東北大学遺伝生態研究センター年報 1997

東北大学遺伝生態研究センター年報 1997

著者

東北大学遺伝生態研究センター

発行年

1997-03

は じ め に

本遺伝生態研究センターは,日鋼口63年に旧農学研究所から新たに設置されて

以来,平成9年4月で10年を迎えます｡本センターが目指した目的は, ｢生態系

における年物種の遺伝的基礎の解明｣でありますが,この10年の間,どのよう

な戦略でこの｢遺伝fl三態｣という新しい研究分野を開拓し,そして発展させて

いくのか,我々は常に自分自身に問いかけながら自己反省と研鍔を心がけてま

いりました｡

我々の新しい試みとその成果を,過去2度にわたって｢自己点検･評価実施

報苦菩｣としてまとめるとともに,さらに国内外の有識者による客観的な評価

として｢外部評価報告書｣を刊行し,世に問うてまいりました｡勿論,このよ

うな数年に一一度の大規模で徹底した点検･評価活動も重要ではありますが,よ

り重要なことは,卜述したように常日頃の絶えざる自己反省と研鍔であること

は言うまでもあr)ません｡この趣旨に立脚して,本センターでは設置以来,毎

年度末に｢年報｣を刊行してまいりましたが,これは 一年間の研究業績を振り

返り,また新たな決意で次年度の研究活動に立ち向かっていく上で,極めて有

意義なことでありました｡

｢遺伝生態研究｣に関しては,平成6年の｢遺伝生態の諸問題｣及び平成8

年の｢遺伝生態情報の可能性｣と越して開催したワークショップに見られるよ

うに,種々の角度から討議を重ね,またこの研究分野の将来における重要性を

確認してまいりました｡今年度は,本センターに課せられた10年時限の9年目

に当たり, ｢遺伝生態研究｣も焦点を結びつつあります｡その意味で,平成8年

度の｢年報｣は単に9年Hの研究業績を振り返るだけでなく,最終年度へ向かっ

て焦点を結ぶべく新たな意気込みとなり,さらにこの｢遺伝生態研究｣が新し･

い学問研究分野-大きく飛躍する原動力となることを願って刊行したものであ

ります｡

関係諸賢のより一一層の御支援と御鞭接をお願い申し上げます｡

平成9年3月

東北大学遺伝/i:_態研究センター良

大 瀧   保

目   次

第1章 部門別研究活動

生態生理研究部門

適応生態研究部門

遺伝子生態研究部門

環境情報研究部門

臨界生態遺伝研究部門

生態システム研究部門(客員部門)

第2章 共同利用研究

ワ ー ク シ ョ ッ フ 共 r司 利 用 研 究

第3章 刊 行 物

刊 行 物 -◎I G Eシリー ◎I S Kシリーズ ◎セ ン タ 一過 ◎ニュースレター

◎外部評価報告書

第4章 そ の 他

外国人訪問者等による特別講義及び特別研究会---･--- 47

人学院学生等名簿

職         員

生態生理研究部門

本研究部門では,植物や徴/1･:物のそれぞれの椎に特異的な遺伝丁情報の発現と/l･:態囚+との関わり を主として研究している｡すなわち,敬/仁物から高等柄物まで,すべての/[:_物が有する特定の形態や 行動(能力)は,その年物に組み込まれている遺伝トに基礎をもつが,その発f射ま光や垂ノJ,さらに 温度や湿度などの/l･:物体を取り巻いている/†三態｢叶子によって人きな影響を受ける｡菌類や単細胞性藻 類などの徴牛物,それに野乍三の高等植物を材料として,これらの遺伝J′一発現に及ぼす/I･:態1人1 i-の影響

とその作刑機作を,主として遺伝学的また牛理学的方法を川いて解析している｡平成8年度における

成果は次のとおりである｡ 接合菌類に属し,光や重力などの外的要l大日こ対して敏感に反応するヒゲカビ(Phycomyces)をHj い,次のような成果を得たo特に今年度は小核的研究機関(COE)研究よしとして11用;茂博十を迎え,

接合反応における細胞骨格の役割に関して人きな成果が得られつつある｡ (1)キチン合成酵素遺伝子卜

の変異の日用旨四:.がある,密なコロニーを形成する形態的突然変異株(遺伝f･ (()I)の接合反応を明らか にした｡ (2)接合反応で対合している前配偶了･嚢を結び付けている繊維を切断したり,細胞の- ･方に障 書を与えたり,また接合を高温卜で行うと,高い頻度で菌糸や胞 (･嚢柄を再fl三するが,これは両前配 偶√･嚢細胞間に認識機構が存在することを示唆した｡ (3)微小管は菌糸,脂(･嚢柄,また接合器官にお いては長軸方向に配向していることが明らかとなった｡ (4)接合器官である前配偶+嚢や配偶(-嚢の中 でも核分裂が起こっていることが明らかとなった｡ (5)ヒゲカどのキチン合成酵素遺伝T･は合計10個の 群から成り17_つていることが明らかになった｡ (6)いくつかの接合反応異常突然変異株を単離した｡ (7) ヒゲカビに近縁なミズタマカビ(Pit()b()lus)の胞丁嚢柄も重力屈性を示すことを明らかにしたo (人瀧帆 宮寄厚,川部茂, 11川奇裕,福井丈) 黄色植物フシナシミドロ( Vaucheria)は管状の多核細胞体制をもつ藻類である｡このLtT_径50-80 /∠mの細胞の基部の 一部を青色光(BL)で照射すると,照射城にすばやく葉緑体が集まり,そのー後, 5-7時間に照射城の中央から1 -数本の枝が発年する｡蛍光抗体法とDAP I蛍光法を川いて, I3

Lによって起こる微小管と核の形態や分布の変化を解析した｡微小管は細胞長軸にまばらに走ってい

るが,葉緑体の集合には関Lj--していない｡微小管は照射開始3 -5時間後にrrJI'滅すが,核分裂に際し

て紡錘体として観察される｡英人な数の核は皮層原形質中で均等に分布しているが,それらは葉緑体

の移動IflにBL照射域へ移動することはなかった｡しかし,登録体集合の完了した照射3時間後に照 射域1^)の核数は増加していたo この増加が核分裂によるものか,移動によるi)のかは検.iJHJである｡ 一方,細胞全体が月瑚すされる,通常の12hL,/ 12hI)のfTJ川音周期ではH朋月開始2 - 4時間後,分裂のピー クを迎える｡微小管のtHl日立と紡錘体の形成,同調的核分裂の光制御機構,枝発/仁-の反応銀と1三態的 意義7LJ:どの研究に着T･し,多核細胞体制の解明を目指す研究グループを作りつつある0 - 1

また,浸透J†:.や膨Ili調節に用いるイオン種が,緑藻や陸l･.植物を含む緑色植物と褐藻やフシナシミ ドロを含む黄色植物で,前者は塩素イオン,後抑ま硫酸イオンであるという点で,大きく異なるらし いことをイオンクロマトグラフイを用いて兄いだしつつある｡このようなアプローチはかつてなされ ていかリが,黄色植物の起源,あるいはマリモの保全を考える卜でも利刷剛bLの高い知見であると期 待している｡ (片l叫博尚) H木花シロイヌナズナの野′I･:集川(12集川)のマイクロサテライト領域に見られるDNA多型から

見た集川の遺伝的難似度と各々の集川の日長及び低温処理に対する衣呪型の類似度との対比を試みた｡

11形質について環境処理に対する反応の大きさ及び様式の類似度をGini係数及びピアソン積率相関で

比較し,平均距離法による系統樹を総平均帆 反応の人きき,反応の様式から作成して集団を比較し

たo この3種籾の系統樹にDNA多賀'_jの系統樹と共通するクラスター,すなわち広島, LIJlrと酒札 LJJ形が得られたが,各クラスタ-を構成する集LIT日詰=二は地理的な連続性が認められなかった｡しかし, DNA多型による系統樹とこれらは良く 一致したことから,刑先をIAl･にする各々の集卜掴ゞ,巽なった

過程で日本に定着し,耕たな分布域の拡大の過程にあることが推察された(京都入学･外底理との共

同研究)0

タネツケバナ集卜射二見られる集川分化と環境適応の機構を各集川の酵素多巧'･!の違いから比較する試

みを遂行している｡国内】3集川を恥､て12酵素椎を対象に変異の解析を現在行っている(京一都入学･ 芝地博幸との)tこいi]研究)｡ (イ1'柴義雄)

1996年1 F]∼12日の問に川行した論文,著書の抄録

Yamazaki, Y., H. Kataoka, A. Miyazaki, MI Watanabe and T･ ()()taki: Action spectra for

photoinhibition of sexual development in Ph_vmm_V川ノ∫ /I/ukHIH,ann.b.･ Photochem･ Photobiol･ 64: 387-392, 1996.

The sexual devel()pment ｡f the fungus I'jz.V('u71_tlm is inhlbited by lidlt･ The action

spectt･a for this photoinhibit(汀y effect were dete1-mined for 4紬continu｡uS eXpOSul･e between 350 and 7OO nm wavelengths duri叩the matinLr prOCeSS･ rl:ffectlVe WとlVelengths weI･e sho上-ter than 490 nm, but the m()st errective wavele岬ths depended ()n the stこIge ()l'S(､xual development･ In ear一y staLreS Of pt･('Lrametanflium formation. the majol･ Peaks appeared neal･:iG() nnl With small sh(,ulders

at 41() nm, I)ul in later _itaHeS, after gametangium fol･mZlti()n. Only siWIe peaks were detected in

the UVA range (350-390 nm). Low-fluence iI･radlatl(m in the later stable. howevell. I-eVealed

inhibit｡l･y effectiveness atニi7()-410 nm. lmplyl叩the existence of a dua一 phut(,.･esp(,IISe and multiple 1-egulato1-y Systems jn the matiniI Pr()CeSS Of I'恒,(,川1_Vr(,LT

Yamazaki, Y. and T. Ootaki: Roles of extracelluar fibrils c()nnecting progametangia in mating of Phycomyces blakeslet,anus. Mycol. Res. 100: 987-988, 1996.

The mating progametangial cells of the Opposite matj叩typeS ()f Phv(Ll)myr(,tb. are

connected by extracellular fibrils. These fibrils were poorly constructed when Phyt.()myct,-q was

mated at hit,h temperature (25Oc) when many pr()Lrameta叩ia were abn()rmally twisted ol-def()rmed and ceased further devel()pmenL Surgical destl･uCti()∩ ()∫ the ribrils also ()ften l`eSulted

in twisting ()r deformati()n ()f pr()gametangia and in cessatl()n Ofthe mating pr()cess. These results

imply that the fibrils may play a r()le t() tietw() progametangial cells alld to maintain their nnrmal three-dimensional configul-ation, which is essential for further mating development.

Yamazaki, Y. and T. Ootaki: Vegetative regeneration on sexual organs in Phycomyces

blakt,sleeanu∫. Mycoscience 37: 2691275, 1996.

PhvClwnyces blab(,/(,eanuS pr()duced an abundance of sexual ()rganS When tw() mating typesmet()n solid medium, butonly about 14.7%ofthesexualorgans developed t()the final stages･ On the sexual ()rgans sh()wing arrested devel()pment, vegetative hyphae or dwarf sp｡rangi()ph()res (micr()ph｡res) often I･egenel-ated. This vegetative regeneration was accelerated

when the paired and 1()oped progametangia were isolated from mycelia, when the counterparts of the progametangial cells constructing the loop were surglCally Incised, and when Phyc()my(-('∫ was mated at high temperature (25-27 ℃). A leaky-carotenogenic mutant, wh()se sexual reactl(m was imperfect and arrested at an intermediate stage even when mated with the wild type, also regenerated hyphae with a h短h fre(1uenCy ()n these arrested intermediate ()rgans. The vegetative regeneration seems t() result from interrupti()n ()f a cell-t()-cell recognltion system between cells ()f different mating type, which is believed t() be essential for the mating process nf this fu叩uS in addition to the pherom()nat acti(1nS.

Kudoh, H., Y. Ishiguri and S. Kawano : Phenotypic plasticlty ln age and size at maturity and its effects on the integrated phenotypic expression ()f life history traits of Ca71damineflexuosa

(Cruciferae). ∫. Evol. Bio1. 9: 541-57(), 1996.

We analyzed varlati()∩ in phenntyplC plasticity ()∫ life hist()ry traits between tw() C〟rd〟mけlCflexu()∫〝 p()pulations based ()n differences in plasticity ()f age and sIZe at maturity. C

flL,Xu().WI (Cruciferae) is a facultative, vernalization-sensitive, long-day annual, and ltS phenology

and the phenotypic expressions Of many life history traits al-e largely controlled by photoperiod

and vernalization ln natural popularions. We used plants from two populations which dlfrered

in their responses to chilllng and potopel-iod treatments. The timing of devel()pmental pr()Cesses

was changed by controlling tempel-ature and photoperjed regimes in growth chambers. Plasticity in size at maturity was analyzed as cha叩eS in a tfr()Wth traject()ry using two parameters, age at maturlty ( △ I) and gr()wth rate (k). B()th traltS Sh()wed plasticity, but differences between the populati()ns were found mostly for △ /. r)istinctive differences in size at maturlty Of individuals ln the tw() populations were mainly due to different amounts ()i plasticlty in △ /. Variati〔)ns in plastlCity of nine other life history and thelr associations to age and size at maturity were also analyzed. Variati()n lor elght of the traits can be described, /at 一east in part, as a functi()n ()f age

and size at maturlty f()r b()th p()pulati()ns, and m()st ()fthe variatl()∩ in the total number ()∫ seeds

was explained by age and s17Je at maturity. Only age at maturity had any effect on changes in res()urce allocation. The nine life hist()ry traits were integrated thr()ugh ass()ciated chatactel-expressions with age and size at matul-ity. Changes in the ass()ciation between a tralt and affe

and / or size at maturity wet-e rather conservative compared to changes in the plasticlty ()f atralt

between the two populations Associat10nSwith age and size at maturlty are mostly explicable

- 3 -in terms of - 3 -inferent relationships - 3 -in the developmental process, and they may llmit the ecol()gical

range expansion and the adaptive evolution of plasticity in Cl. /lexu()tm. The negative correlation

between repr()ductive allocati()∩ and age at maturity can be a c()st r)f delaylng maturatl()∩ in C

fl(,xunLm.

Shibaike, H., Y. Ishiguri and S. Kawan(): P()pulation differentiati()n in fl()l al and life hist()ry traits of Oxalis cwniculaia L (Oxalidaceae) with style length polymorphism. J. Plant Res. 109:

315-325, 1996.

A quantitative genetic analysts Was C()nducted ()∩ the am()unts and distribution of variation of 20 floral, reproductive and life histoIY traits of a self-compatible perennial. ()xall∫

mrnz'(7Llata 1, (Oxalidaceae). This species comprises two floral morphs, homostyled and

long-styled, with different breeding systems. The hierarchical design ()∫ the experiments ()∩ three homostyled and three long-styled populations allowed partitionlng ｡f variatlOn into four levels

()f organization using nested ANOVAs. Seven of the 2O traits examined were differentiated

between h()m()styled and 1()ng-styled populations, Significant genetic varlanCe COmp()nentS Were

detected in the major traits (114 ｡f the 120 tl-aits) examined for six p｡pulati()ns. Average values

of variance components among families within a population across 20 traits for hom()styled

population were hlghet- than those of long-styled population. These responses likekly reflect the

consequences of different levels of selfing and / or mixed mating on genetlC Variation in the tw()

fl()ral morphs ()I a. (()rnlrld(/ta. Pearson product-moment correlations for famlly means ()f seven traltS Selected were also calculated. Tw() gr()ups of trait combinations (i. e., between fl()ral traits,

and between reproductive and life hist()ry traits) sh()wed significant family mean correlatlOn

coefficients. The origins of these variati()n patterns found in different populations of ().

C()rnlCZilata are discussed in terms of the underlying selective regimes operating in each p()pulati()∩.

学会での口頭発表,展示発表

人瀧 保:ヒゲカどの形態形成と行動｡ ｢きのこの新基礎科学とバイオテクノロジー｣講演会(1996年 1月25,東京) 大瀧 保,山崎 裕:ヒゲカどの接合器抑こおける栄養菌糸及び胞子嚢柄の軸/I:.｡日本菌学会第4OkuJ 大会(1996年5月25-26日,筑波) 官軍 厚,大瀧 保:マルチゾーンファミリーを形成するヒゲカビキチン合成酵素遺伝｢｡日本菌学 会第4O巨｣大会(1996年5月25-26日,筑波) '喜L.}1.1摩,人瀧 保二糸状菌ヒゲカどのコロニー形成変異体(col)について｡日本植物学会第60lPl大 会(1996年10月10-12日,鳳叫) 大瀧 保, lLJ崎 裕:ヒゲカどの接合器官F･.の1ヰ/I-:｡日本植物学会第6O回大会(1996年1O月1O-12H,

福岡)

rH部 茂,大瀧 保:接合菌ヒデカどの/冒古環における細胞骨格の分布｡日本植物学会東北支部入会

(12月14日,仙台) 一 4

山崎 裕,片岡博rl!.'J,官軍 厚,大瀧 保:ヒゲカどの接合- f一形成における光阻害.日本植物学会東 北支部大会(12)j14U,仙台)

Miyazaki, A･, T･ Ootaki: Multiplegenes for chitin synthases in a zygomycete fungus Phycomyces

blaかJJetY1nZiS. 2nd Internati()nat Symposium on Chitin I工nzymology (1996年5月8日∼1川,

Senigallia, Italy )

Miyazaki, A., T. Ootaki: Cloning and characterization of chitin synthase genes fr()m Phyc()my(:e∫

blackleeamts. Asian International Mycological C｡ngress '96 (1996年- 7 )i 3口,千葉)

LIJn奇 裕, JIT･岡博尚,宮掲 厚,渡辺正勝,大瀧 保:ヒゲカビ接合J丈応における光r汀借の作用スペ クトル｡日本植物/l三和学会(3月27-29日,鹿児島)

高橋文雄,菱沼 仏,片岡博尚:青色光局所照射が誘発するフシナシミドロの同調的核分裂｡ H本植

物学会東北支部第10担j大会(12月13-14H,仙台)

Shibaike, H., Y. Ishiguri, S. Kawano: Genetic variation and relati()nships of Japanese population of Oxalis (I()rniculat(1 L. (Oxalidanceae) detected by random amplified polymorphic DNA (RAPII)). International symposium: "I)ifferentiatinn patterns nf plant populations and adaptive mechanisms" (April, Kyoto).

1､()d()ko1-0, S., Y. Ishiguri, S. Kawano: Ecological genetic analysis of natural populations ()f Arabidopsis in Japan. International Symposium: "Differentiation patterns of plant populations and adaptive mechanisms" (April, Kyotn).

Ishigut･i, Y., H. Kudoh, S. Kawano: Environmental regulation of life cycle and population

differentiation in the species of Cardamine. Korean Ecological Congress (May, Seoul, Korea)

Shibaike, H., Y. Ishiguri, S. Kawano: Breeding systems and genetic variation of natural

populations of Oxalis c()rm'culata with style length polymorphism･ Fifth International

適応生態研究部門

当研究部門では,耕地′Ⅰ-:態系を含む'{態系に存在する植物の遺伝的変異を解明し,椎々の環境スト

レスへの適応に有川な遺伝了･資源の開発に資するとともに,これら特定環境に対する植物の反応性

適応性を研究している｡ tf7-成8年に得られた成果は次の通りである｡ 乾燥ストレス1日I避のために機能すると考えられる根の水分lEIi.性発現のための条件および発現様式を, 新たに確､II･_したモデル実験系によって解析してきた｡前年度の研究で,この水分屈性のための偏差生

長が伸長帯の細胞壁伸展性の偏差的な変化を伴うことをはじめて明らかにした｡そこで今帖ま,その

細胞壁仲展性を制御するとされるエン門竺キシログルカン転移酵素遺伝/-(EXGT)を突然変異体エ

ンドウから単離し,その遺伝子発現と根の水分屈性の関係を明らかにした｡

(高橋秀幸,藤井伸治,高野 守) また,水分fEg･FLl･･.における刺激感受とシグナル伝達機構を明らかにするため,刺激感受部分の根冠か

ら械曲反応部位の伸長滞-のシグナル伝達の特件,根の刷iにおけるカルシウムの関与について,水

分屈性と垂ノJ屈性を比較しながら解析し, I山州件反応に異なるシグナル伝達機構の存在することを明

らかにした｡       (C. Ⅰノ. Stinemetz,高橋秀幸) 地球外環境における植物/tI台の問題点を探る手段として,重力に対するll-A.常な反応を失った変異体 を用いて研究を行い,これまで明らかにした特件を遺伝的に理解するため,サブトラクト法によって

オオムギ突然変異体と野生種の問の遺伝子発現の差を解析した｡ (藤井伸治,高橋秀幸,阿部清美)

また,重力形態形成としてij:_Hされるウリ科植物のペグ形成機構を解明するために,キュウリ芽′1三 えからオーキシン制御遺伝+ (AliX/SAUR)およびエチレン受容体遺伝+ (ETRl)を単離し,普 /I-:えの発育およびペグ形成とそれら遺伝1･発現の関係を明らかにした｡ (藤井伸治,高橋秀幸) さらに,ペグ形成のためのタ-ゲット細胞を特定し,それらの′l:_長極性の変化･亜力感受と細胞骨

格の関係を解明するために,チューブリン染色を行い,ペグ形成における微小管の配向変化の役割を

研究している｡      (高橋秀幸,小林真由美)

強磁場が植物の発育∴量佃勺変異に及ほす影響を明JJかにするため,本学強磁場超伝導材料研究セ

ンターとの共同研究を行っている｡これまで,植物の′1･満は4テスラの強磁場によっても阻害されず, 逆に,アラビドプシスの発芽と芽′I-:iの伸長隼長は強磁場卜で有意に促進されることがわかった｡ (高橋秀幸,藤ナ日中治,阿部清美)

6 -植物資源保全に関する研究では, (1)シバ(Zt)ysia)属の一種であるコウシュンシバ, Z matrellaの

九州北部生丁場の分布が確認され,本属の人型種と小型種とが海辺地域において隣接生育する希な例

と考えられた｡ (2)暖温帯に自′けるネザサ, Pleiobla.dus chinovar. 1'iridis.の開花結実は, 1992年

頃に本学のスタンドで観察されたが,本税象の解析に資するため,本年は九州阿蘇産の本椎を導入し,

実験スタンドの育成を行っている｡       (庄pl舜一)

乾燥地への適応にイ川とされる植物の深播き耐性に者目し,禾本科植物の節間伸長制御機構とその

遺伝的変異に関する研究を行っている｡前年度は中国在来種の超深播き耐性のコムギ占占種の節間伸長

が,エチレンによっても著しく促進されることを兄いだし,陸上植物の節間伸長におけるエチレンの 役割を示したが,今仙ま,日本のコムギ品種にもエチレン感受性の著しく高いものが兄いだされた｡ また,これら深播き耐性種と一磯品種の雑椎(Fl, F2)を作出して,深播きおよびエチレンに反応し て′1三じる節間伸長の遺伝解析を行った｡         (西洋武恥骨 洋,高橋秀幸)

1996年1 ll-12月の間に刊行した論文,著書の抄録

stinemetz, C., H. Takahashi and H･ Suge. Characterization of hydrotropism: the time of perception and signal movement from the root cap in the agravitropic pea mutant, ageotroPum･

Plant Cell Physi()1. 37 (6): 800-805, 1996.

In this study, 〟ge('trt'Pum pea mutant was used to determine the threshold tlme for

perceptinn ｡f an ()sm()tic stimulation in the lWt Cap and the time requirement for transduction

and transmissl('n ('f the hydrotropic signal from the rnnt cap t(, the el(,ngation region･ The

thresh()ld time for the perception of an osmotic stimulation was c()mpared to current estimates

of threshold tlmeS for graviperception in roots･ The time re(1uired for transduction and

transmission ln the hydrotropic response of agE!''tr''Pum was compared to the time requirement in the gravity resp()nse (-∫ Alaska pea r｡('ts･ We determined that threshold time ∫(,r perception of an (Ism('tic stlmulati('n ln the root cap is very rapid, occurri叩in less than 2 min following the applicati('n ''fsorbltOl to the root cap･ Furthermore, a single5min exposureofsorbit('l to the root

cap fully induced a hydro,t1-0Pic response･ We also found that transduction and transmission of

an osm()tic stimulus requires 90112() min i(W movement from the r()Ot cap to more basal tissues involved in differential growth leadi叩tO r(I('t Curvature. The very rapid threshold time for

perception of root hydrotropism is similar to those times reported for root fUaVitropism･ However,

the time required f()rthe transduction and transmission of an osmotic stimulati(,n fr()m the ro()t

cap lS Significantly 1()nlirerthan the time re(1uired in iiraVitropISm･ These results suggest that there

must exist some differences between root hydrotropism and graVitr()pism in either the rate or mechanisms of transduction and transmlSSion of the tr()pistic signal from the root cap･

一一一 7 -Takahashi, H., M. Takan(), N. Fujii, M. Yamashita and H. Suge. Induction of hydrotr()pism in

clinorotated seedling roots of Alaska Pea, Pislim SatiJノ㍑m L. J. Plant Res. 1O9: 335-337, 1996･

Roots of the ail,raVitropic pea (PJJJLm J〟/tt,Hm L.) mutant (LgH)tr()f･lWt Sh()w positive

hvdr()tr('plSm, Whereas r()I)ts ｡r Alaska peas are hvdrotl･OplCally almost non-resp()nsIVe･ When

the i,raVitr()plc I-eSpOnSe Was nullified by l-()tatlOn On Clinostats, however, roots (,f Alaska peas sh()wed une(1uiv()cal positlVe hvdTOt1-0PISm in response to a water p()tential gradlent･ These I･esults suggest that ro()ts of Alaska peas possess normal ability tO I-esp()nd hvdr()tr()pically and

theil- Weak hyd1-OtrOPic I-eSpOnSe results from a counteracti叩effect (,i graVitr｡pism･

Abe, K., H. Takahashi and H. Suge. Lazy gene (la) responsible for both an agravitropism of seedlings and lazy habit of tiller growth in rice (()ryza LWltzll,lI L.). J. Plant Res･ 1()9: 381-386, 1996･

Using an isoLrenlC llne ('f rice havinきI lazy gene (lu), we studied the correlati()n between the aLlraVitroplC response at the y()un ff Seedlinti, Stage and the 一azy ha一).t (prostrate脚1)Wth (,f tillers) at the more advanced stage ()fgrowth. In this study, itwas found that both a灯aVltrOpism and lazyhabitwerecontrolled bythesinglerecessIVe /(1gene･That is･F2Se即e糾ntS()fKamen()0 ×

lazy-Kamen｡0. which had an agl･avit1-0Pic response at their y()unLr SeedlinLi, Stage･ Showed a lazy

habit ()f gl-OWth in the more advanced stage of veLletative抑)Wth･ On the ()ther hand･ seedllnfIS that showed normal gravitropic curvature at their early stage Of gr')Wth had an upllght g1-0Wth in the mature stage.

Takahashi, H. and H. Suge. Promntinn nf callus formati()n by nun-injuri()us mechanical

stimulati()n in bean stems. Bi()logical Sciences in Space. 10 (1): 8-13, 1996.

we have examined the effect ()f nun-injuri()us mechanical stimulation on callus

f()rmati()∩ ()ど stem tissues. Mechanical stimulation by l･ubbi叩Substantially pr()m()ted the

w()und_induced callus formation on the stems of beans (J'haW,()luLH'Zl/i,(IrlJ I. ). 'llle pr()m()tlOn

of callus f()rmation also was observed in zn t'7/rl)Cultul-e Of the tissues excised from mechanically stimulated stems of beans. The results Imply that mechanica一 stimulati()n induces s()me physi｡logical change preference for cell division in deve】opiniI Callus･

I.I.:I.Y.･j藤乱菅 洋.イネ( OryzaLmtil'aL.)の潮は処埋による種了･稔件の低卜と穂におけるr^J′f･:ジ ベレリンとの関係.育種学雑誌. 46:173-178, 199G. 榔止冊′1三に弟少!･がある染分とササニシキを供試して.葉耳rHH圭一′1から+ Hcmまでの穂の発脚立 附のpijf-,たものをHinun15oC夜温1()oCの榔且で1(川rHJ処理し,その椎/一稔性に及ぼす影響を調べるとと い二.穂の内'fIジベレリン分局を調たしたo冷7tLLに遭遇させる時期かtli一いほど柁/僚F'′lA.は低卜したが, r"..椎Ftりでその柑狛二美歩きが.,思められ,ササニシキのjjが稔性低卜が苦しか-)たC潮温処押しtiLいものに 比較すると,冷温処椎によ-,て穂のr^J′l:ジベレリン付足はIll･j.I..1,椎とい二著しく低卜したが,冷温処押卜 でのジベレリンの減少fL,l=.T生はササニシキでむしろ少なく,冷温処理しないものとの比較ではササニシキ の)}-がジへレリンの伐†rする比率は大きかった｡ササニシキにジベレリン′Iイナ成l;lL'rriI剤のS-t'127I)杏 処押してから榔昆処理を5 L川口処理したものでは,薬剤処坤によ-'てFJ,J'1-:ジベレリン合墓が低卜すると IilJH与に,粕に築耳聞長が() ∼4(､mの発ffA段階での冷温処坤に対して.ジベレリン′卜合成l;J措剤処坪によ る椎(一稔作の向Lが-.思められたoこれらのことから,減数'JI裂期の冷温処LIIHこよる椎(稔作.の低卜には l^11二ジへレリンのレベルが問Ij･しているnl能性が′Jミ唆される｡ 8

酉揮武明,菅  洋.イネ科植物芽′ト:えのPhenotypic plasticityにおけるエチレンと二酸化炭素の相 El二作用.日作東北支部報. 39 : 75-77, 1996. 睦卜植物をmいて, (･菓紺,中辛.第 -節間の伸長に対するエチレンと 二酸化i･k素の作用を検討 した｡ ･椴にエチレンは水/l三,平水/1二植物の縦jj向の伸長を促進し, A.酸化)Lk素はその作用に協調的に 働くことが多く,随卜植物では,エチレンは縦方ILu)の伸長を[)'rl'.ifして,二酸化J夫素はその作TI)に打抗す る｡しかし,本研究結果から,エンバク,トウモロコシ,コムギの陣L植物でもXJ-′I-:えのある器付はエ チレンによって伸長か促進されることがりJらかになったo この場合, _酸化7,11素は,トウモロコシの申 貨およびエンバクの†.紫抑･ rf.貨の伸長を促進し,水/用a-_物の場合とIliJ様にエチレンとの協調作用を′Jミ したが,コムキの第 -節問ではエチレンの促進作用と才封)'LL,伸長を抑制したo

その他の川行物

藤井伸治,高橋秀幸,菅  洋:キュウリ芽/l･:えにおけるオーキシ制御遺伝子(Ala/IAA)の発現 解析｡宇ILil利用シンポジウム(第f-三川).日本学術会議･宇宙科学研究所｡ 13 : 15-18, 1996.

学会等での目頭発表,展示発表

高橋秀幸:無串-_力と植物 一植物の宇宙実験-｡東北宇宙/I-:命科学シンポジウム(第2山) ｢宇宙科学 の未来｣ (1996年31130日,福島)

Takahashi, H.: Gravimorphogenesis: the gravity-regulated formation of peg in cucumber

seedlings. Internati()nal W()rkshop on Plant Bi()1()gy in Space (June 24-27, Bonn, Germany)

藤什伸治,高橋秀幸,菅  洋:キュウリ芽/1-:えにおけるオーキシ制御遺伝+ (Aux/IAA)の発現 解析｡宇柄利用シンポジウム(1996年7月30-31日,東京)

藤Jr伸治,高橋秀幸,菅  洋:キュウリ芽件えの電ノJ形態形成における遺伝月毛現の解析｡日本宇

Idi/l･:物科学会(1996年9日5-6円,京都)

Stinemetz, C., H. Takahashi, H. Suge : Characterization of the hydorotropic response of roots. H本宇宙牛物手中学会(1996年9月51(Hl,京都)

Stinemetz, C., H. Takahastli, H. Suge : Ca2+ -induced root curvature in the nongraviresponsive

l1g(,()tr()Pumpeamutant. (1996年9月5一6日,京都)

ド･摘H育英,藤井伸治,高橋秀幸,督  洋:突然変異体を利用したオオムギ芽牛えの重力反応の解析｡

H本芋揃/I:.物科学会(1996年9日5-6日,京都) 菅 11-羊,西洋武明,武凹和義:コムギの深播きによる第 一節間伸長の可塑性とエチレンによる伸長 促進o H本作物学会(1996年4H3-4日,宇都宮) 菅  洋,州等武目礼 武川和義:コムギの深播き適応性:節-･節間伸良性のエチレン反応性の遺伝｡ 日本作物学会(1996年10月2-4日,秋山) 西洋武明,菅 洋:イネ科植物芽牛えのPhenotypicplasticityにおけるエチレンと二酸化炭素の相 互作川o 日本作物学会東北支部会(1996年8H22-23tl,崇41-) 高橋秀幸:根の水分屈性に関する研究｡口本根研究会学術功労賞受賞講演(1996年1OH26日,名rfr屋)

･遺伝子生態研究部門

当研究部門では, ｢人為的に遺伝f-を改変した′I:_物の'T･'.態系における動態｣を享:.要テーマとして,植 物および徴′1二物を対象に研究を進めている｡本年度は以卜のような研究をおこなった｡

細胞融合研究の新展開｢植物ゲノム改変法の開発｣をlH持して,本年度も遠縁間植物の細胞融合と

その雑種植物の遺伝召芭税について検討した｡その 一つとしてオオムギの有する低温や塩に対する抵

抗性をイネに導入するために,細胞融合法を用いて体細胞雑種植物の仲山を試みた｡プロトプラスト

の単離･培養条件等について検.けした結果,オオムギにおいては無菌的に't-_育させた幼植物の葉肉細

胞を用いた場合,イネにおいては懸濁培養細胞を用いた場合,プロトプラストの調整が最も容易であっ

た｡また,融合後, 1%NaClを含む借地で選抜することにより,明らかに塩に対して抵抗性を持つ細

胞が得られることが分かった｡しかし,選抜した細胞から植物は細分化せず,塩に対して抵抗性を持

つ植物は得られていない｡さらなる検討が必要である｡

トウモロコシ培養細胞とその細分化植物および長期間保存した種子の分裂中期の染色体を,間接蛍

光抗体法により,観察した結果,反復配列の多いトウモロコシゲノムにはDNAのメチル化が高頻度 で認められた｡さらに,その染色体のメチル化は, -テロクロマチンこぶにおいて多く牲じているこ とが明らかなり､染色体異常には, DNAのメチル化が関係していると考えられる｡ 食用アスパラガス( Aspar'lguS ''NicinaliLtl L. )は雌雄異株植物であるが系統的にアスパラガス属植 物の多くは雌雄r,iJ株である｡このアスパラガス属植物の系統関係を葉緑体T)NAのRFLP及びRA

pD法により解析した結果,雌雄異株のアスパラガス属植物は雌雄同株の種から幣系統的に生じてき

たことが明らかになった｡また食用アスパラガスのリボソームDNAのクローニングを行い,その制 限酵素切断パターンの,r77.4_垂問差異を解析した結果,食用アスパラガスの品仲間では差がなかったこと から針fげスパラガスの裾"I.種は遺伝的に非常に近いことが明らかになった｡食mアスパラガスの核 型(Karyotype)分析では,食用アスパラガスの染色体2()本のうち4本にサテライトが存在すること がわかった｡また食用アスパラガスの花芽形態形成遺伝√∵単舵を試み, APETARA3遺伝 (･のホモロ グをRT一Ⅰ,CRにより単離した｡(木坂広軌六川押一郎,アントニオ･フルミニヤン,津久井利広, エフェンディ,北澗絵里奈,菅野 nJl,亀谷寿Hli) 遺伝f-改変徴′1ミ物の′Iミ態とその利川:柄物紬歯痛の防除剤として汎用されている釧剤との仲川を吋

能にし,減農薬に資するため′Ⅰ勃防除剤の銅耐性化の研究を進めた｡軟腐病菌410肉林の硫酸銅のMIC

は400/Lg/mEに1つのピークを形成する分/h-パターンを示した.硫酸銅80O/1g/mEで′用する年三物防除

剤を得たo鋼耐性の程度については琉酸銅と市販の銅剤との間で相関性は認められか､｡ -クサイ汁

川

液中のバクテリオシン誘矧大けの検定法を確定し調べた結果,誘矧大11-はpH4.5-9.0で安定であり, 酸性,アルカリ性の両条件卜で,クロロホルム,酢酸エチル, n-プチルアルコールなどの分画で抽出 されなかったTn5 (pJB4JI)を用いリファンピシン耐性の軟腐病菌との接合体約5500菌株を分離し, これによりバクテリオシン産/l三能の欠失した数菌株を得た｡これらり菌株を使用し, TAIL-PCR法に よりバクテリオシンの産/I:.に関わる遺伝子の約500塩基配列を決定した(郡F,l祐一,荘 敦寛,チメレ･ アンバービン･ジェドゥ,菊本敏雄)

1996年1月∼12月の間に刊行した論文,著書の抄録

Yoshida, R., A. Kanno, T. Sato and T. Kameya: Cooトtemperatue-induced chl｡rosis in rice

plants. 1. Relationship between the induction and a disturbance ofetioplast development. Plant

Phys101. 110: 997-1005, 1996.

We have established an experimental system for mlmicking the phenomenon of

cool-temperature-induced chlorosis (CTIC) in rice plants (Oryza satll,a L). Rice seedlings Were

initially gr()wn in darkness under co()I-tempel-ature C()nditinns and then exposed t() light and

warm conditions to f()ll()w the expression ()f CTIC. Induction of CTTC in the sensitive cultivar

(cv Surjamukhi) was bim()dally dependent ()∩ the tempel atureS experienced during the initial

growth in darkness. CTIC was maximally insuced between 15 and 17cc. A positive correlation was demonstrated between inducti()n ()f CTIC and the gl･()Wth activity of shoots during growth in darkness. Electr()phoretic and immun()blot analysis I-eVealed that accumulatir)n ()i NADPH-pr()t()chl()r()phyllide ()Xidoreductase in plastids was als() blm()dally dependent ()n the

temperatures duri叩thegrOWth in darkness wlth minimum accumulati()n berween 15 and 17cc ,

suLrgeStlng that reducti()n ()f NAT)PH-pr()t()chl()r()phylide ()xldoreductase accumulati()n in

plastids might be cl()sely linked t() a disturbance ln tranSf()rmati()ns ()f plastids to etioplasts

during the dal-k growth under the critical temperatul`eS and thereby to the CTIC phenomenon. This was corrobol･ated by electron micl･()SC()pie observations. These results suggest that growth

is one of the determining factors for the expression of C'HC phenotype in rice under cool

temperature.

Yoshida, R., A. Kanno and T. Kameya: Co()1-temperatue-induced chl()rnsis in rice plants: ⅠⅠ.

Effects of cool temperature on the expression of plastid-encoded genes during shoot growth in darkness. Plant Physi01. 112:585-590, 1996.

It has been proposed that c()()I temperature-induced chlor｡sis (CTIC) in hl(h'(･(1CultivaI-S

of rice (Oryz(1 Sllfit,〟 I,.) is caused by cell gr()wth and plastid development being impeded at cool temperatures. Since it is well known that the overall rate of tl･ansCription of plastld-encoded genes changes dramatically during the early phases of plastid development. in this study we focused on the patterns of expression of these genes. Northern blot artalvsis revea一ed that the level of 16S

rRNA is decreased in a CTIC-sensitive rice cultivar Llr'()wn at a cool temperature, The expr'ession of the gene for the B subunit of plasmid RNA polymerase (rf1()B) was sh()wn to be s()mewhat disturbed, particalarly in terms ()f its resuppressi()n under c()ol c()mdltions. The level of

transcripts ()r pr･oteins of plastid-encoded photosynthetic genes was also decreased in a

CTIC-sensitlVe Cultivar at a cool tempt.rature. These results suggest that the

dependent inhibition of the onset of gene expressi()n enc()ding the transcript10n / translati()n

apparatus may be primarily involved in the mechanism causing CTIC.

valizadeh, M., K. K. Kang, A. Kanno and T, Kameya: Analysis of genetic distance among nine

Mcdicag(I species by using DNA polym()rphisms. Breeding Science 46: 7-10, 1996･

The relationship of 9 MddlragOSpeCies belonging to 4 subgenera Was analyzed by using

restriction fragment length polymorphism (ItFLP) meth()d()I()tries, We ana一yzed 85-132 RFLl'

band patterns, which were caused by chloroplast I)NA variations, t() estimate thegenetic distance

am()咽the species, These species were clustered together at around O･l to O･4 level of distance f()r marker, indicating that the Mt,di(･〟gl)specleS have a la1-ge genetic similarlty. The m()st similar specleS Were M litt')yuliJ and M. fran(､〟tlilu and the most dissimilar ()ne was M. /uf"Llin〟. The cluster analysis based on RFLP band patterns differentiated 9 species in an()ther4gr()ups: a) 〟

littoralis, M. trun(･atLila, M. srlitellata alldM ∫〝tlL'a: b) M. (H′blrul(Jn5 〝n(lM radwlt〟 ; C) M･ rt,gldlll(I an(I M. mmtma ; d) M. luf,u/ina. Compari叩the previous classificati()n I,f M"l打〟g,) SPeCleS With

that in this study, there are tw() discrepancies･, M lliPulin'I is the most dlStant Species from othel-s

and M twltWa (subgenus Medi'.ag'') was cl()sely clustered with M ､rNf`,ll〟tu. M ll'ff'7m/l∫ and M･ trunl.lJtula classified in subgenus Splrl)ClLrPu∫.

Kisaka, H., M. Kisaka and T, Kameya: Characterization of interfamilial snmatic hybrids

between 5-methyltryptophan-resistant (5MT-resistant) rice ( Oryz(I s〟ti7)〟 Ⅰ..) and 5MT-sensitive

carrot (Daucus carota L.); Expression of resistance to 5MT by the somatic hybrids. Breeding

Science 46:221-226, 1996.

The production of the asymmetrlC hybrid plants between

5-methyltryptophan-resistant (5MT-5-methyltryptophan-resistant) () satu'(1 and 5MT-senstive /). ((lr')f〝was reported previously. Alth()ugh morphology of the s()matjc hybrid plans cl')sely resembled that ()f the parental carrot plants, all

()I the somatic hybrids were resistant to 5MT･ In the present study, we investigated theexpressi()n ()f resistance t() 5MT in cells ()f these somatic hybrlds, The calli induced from hybrld plants and their parents grew in medium that contained a high c()ncentl･atlOn Of 5MT when th()se calli were

supplied with anthranilic acid ｡r tryptophan･ However, ch()rismic acid was ∩(,t effective in

reducing the inhlbition of cell growth by 5MTI The activities of anthranilate synthase and

tryptophan synthetase of cells of the somatic hybrids and 5MT-resistant O･ S〟tz'Z,a were about 5 times and 2 times as high as those ()fceHs of5MT-sensitive D. `･〟rofu. 1･eSpeCtively. These 1-eSults

lndlCated that anthranilate synthase was involved in the mechanism of resistance t(- 5MT･ However, anthranilate synthase actlVlties of the somatic hybrids and 5MT-resistant () tvl/Zl'(lWere quite sensitive to feedback inibitation by tryptophan, as was that of 5MTISenSitlVe I)A (-ur,'t(1･

N()rthern hybridizati()n using a gene for anthranilate synthase as pr(,be revealed that levels of

expression of the gene in the somatic hybrids and 5MT-resistant () ∫〟tz'zv/ wet-e h画一er than that of 5MT-resIStant I). (〟t()fa. Furtherm()I-e, the somatic hybrids c｡ntalned the gene fol anthranilate synthase that originated from 5MT-resistant r)･ ∫〟tH,'I･ These suggested that the l･eSistance to 5MT in cells ofthesomatic hybrids was tI･anSferred fr()m that ()f5MT-resistant () Ldz7,〝thr(,ugh cell fusl()ll.

Fluminhan, A. and T. Kameya: Behaviour of chr｡m｡somes in anaphase cells il- embl･yOgenic callus cultures of maize (Zed mlIyS I,.). Theor. Appl. Genet. 92: 982199(), 1996.

Mit()tic anaphase cells ()f hlghly friable and embry()genic caHuses which had been

induced from immature embryos of two inbred lines of maize that have c('ntrasting levels of

haterochromatic knobs were analysed f()r the presence ()i abn()rmallties 3, 6, 9 and 12 monhts after

the initlat10m ()fculture. A total or500typical anaphases was scored at each time p()int, and various

aberrations. such as delay in the separation of sister chromatldes, chrom()some bridged (single, d()uble and multiple) and chr()mns(1me fragments, wet-e revealed t(日)ccur extensively in the cultures ()f both genotypes. Prepatati()ns after C-ban°ing revealed that primary breakages often occurred inside kn()bs ()r at junction regi()ns between the euchr()matin and the heter｡chr()matin ()f the knobs. FlgureS Characterized by the delayed separati()n ()f sister chromatids, which orlginated preferenitlally at the knob level and was considered to be an initial ln thedevelopment of bl-eakages, were obsel･Ved at constant frequencies throughout the experlment. Increaslng

numbers ()i aberrant cells were detectedwith time, mainly due to the accumulation of cellswith

chr｡m()S()me bridges and fragments. Several nit()tic figures suififeSted the occurrence of

breakagefusion-bridge cycles that were initiated by br()ken chr()m()S()mes. The overall

fl`equenCies of aberrant cells were similar ∫()r both gen｡types, despite the differences in kn()b

composition. However, callus cultures Induced from thegen()type having the higher level of knobs

had m()re aberrant cells with abnormalities that involved several chromos()mes, such as multlPle briges and multiple fragments.

Niwa, T., A. Kanno, N. Tsutsumi and A. Hirai: Detailed mapping ()f the chloroplast genome of

barley, H()rdL,lLm I)ulgare L Genes. Genet. Syst. 71: 175-180, 1996.

The chloroplast I)NA (ctDNA) of barley (H()rdeum HJlglIrl,IJ.) was is()lated from y()unLr

green leaves and fragments after partial digestion with St7u3A were cloned into a lambda phage

vect()r, Using an overlapping clone bank ()f the entire chloroplastきIenOme Of barley, We mapped

the cleavage sites for the enzymes XbaI, Hindlll, PtM, S(Jlland Ptil,IIprecisely on the circularl)NA.

The chlor()plast genome of barley was found to be 137 kbp long and to contain a pail･ ()f inverted

repeat reか)ns of23.7 I 21.1 kbp that separated two single-copy regions of81.7 - 81.1 kbp and l3.2 I

1().6 kbp, respectively. The restrlCti()n map ()f the barley chloroplast genome showed a high deifree

()f c()nservat10n Of restriction sites relative to those in the chloroplast genomes ()fwheat and rye.

The ii,enes for 13 transfer RNAs and 33 chl()roplast proteins were identified and I()cated ()n the

barley chl()r()plast gen()me by hybridizati()n with fragments ()∫ rice ctI)NA that c()ntained the

corresponding genes. The locations of the various genes are very similar to the respective

p()siti()ns ()n the chloroplast genome nf rice and maize.

学会での目頭発衣,展示発表

菅野 明,亀谷寿昭:食川アスパラガス属柄物の系統解析｡ u本百柁学会(4月2-3日,東京) 鈴木良1-,菅野 n仇亀谷寿昭: RAPD法を川いたアスパラガス属植物の系統解析｡ H本育種学会(4 日2-3日,東京) 沈一札朴棚龍､妾権圭､康一一隻､亀谷寿昭‥ RFI-P及びFinge/rprinting法によるトウガラシのDNA マ-か-と類縁関係｡日本育種学会(4日2-3日,束京) Fluminhan,A.,近il二),A仲子,福井希 -,亀谷寿昭: FISH法を川いたトウモロコシ長期紺呆存種1･ における染色体異常の分析｡日本育椎学会(4日2-3H,東京) 13

吉｢11牡一郎,菅野 明,佐藤稚志,亀谷寿昭:イネの低温クロロシス感受性とストレプトマイシン感 受性との関連性｡日本育樺学会(4月2-3日,東京) 李栄口,妄権圭,亀谷寿昭:サツマイモにおける2-aminoethyl-Lcysteine耐性株の選抜｡日本育種学 会(4月2-3日,東京)

木坂広明,菅野 明,亀谷寿昭二ニンジンとオオムギの科間体細胞雑種類植物の解析. H本育種学会

(4112-3日,東京) Efendi,木坂広明,亀谷寿昭こアグロバクテリウムをもちいた大豆( Glycinemax)の形質転換体の 作出と解析｡日本育種学会(9月27-28日,仙台) 菅野 明,亀谷寿昭:アスパラガス属植物におけるrDNAの構造の比較解析o R本育種学会(9月271 28日,仙台) Fluminhan, A.,近江戸伸｢,福井舟一,亀谷寿昭:間接蛍光抗体法を朴-た植物細胞に置けるDNA メチル化の分析｡日本育種学会(9月27-28日,仙台)

木坂広明,木坂真由美,菅野 明,亀谷寿昭:細胞融合によるイネとオオムギの属間体細胞雑種植物

の作出と解析｡ H本育種学会(9Tl27-28日,仙台) チレメ･アンビン･ジェドゥ,荘 敦克,郡司祐 -,菊本敏雄:野菜類軟腐病菌の銅耐性｡日本植物 病理学会(10月3-4日,盛岡)

14 -環境情報研究部門

当研究部門では, t壌徴牛物の生態･機能および土壌の化学性を研究することによって,地問につ

いての稚解を深めることを目標に研究活動を行っている｡本年度は以卜のような研究を行った｡

極めて多数のRSα, RSβなどの挿入配列のコピーを有するダイズ根粒菌超反復配列保有株(HRS

柿)が特定の圃場から分離され, HRS株は土着の通常株から挿入配列の介在するDNA再編成によっ

て各圃場Jf二態系の中で/f･:成したと考えられた｡そこで, HRS株が遺伝子水平･伝達の供与体になってい る可能性を考え,その遺伝/f･:態的意義の検討を行った｡低温処矧刈こおいて, BradyrhizobiumjaPonicum

HRS株NK 5株のnod遺伝了･がnod遺伝子を破壊した根粒菌B. elkaniiUSDA94 △ NODに水If'-一伝 達された｡ nod遺伝f-を獲得した菌は機能的にも州吏していた｡以上の結果は,ダイズ根粒菌HRS株

のような激しいDNA再編成を受けた細菌が,一卜壌環境中において様々な遺伝子の供与体になってい

る[･(能性を示唆していると考えられた｡また,人部分の:t壌細菌が培養困難な細菌であることの分+ 諭的基礎を明らかにする一環として,アルファルファ根粒菌を対象として,グローバルな転写調節因 子である各種シグマ朴f･のクローニングを行った｡       (南洋 究,三井久幸)

作物生産に開通した土壌環境条件の変化に対応した土壌ミクロフロラの変動について検討を行なっ

た｡ (1)農薬と土壌ミクロフロラ:16年間ベンチオカーブを連用した水田土壌の細菌フロラを明らかに

するために分離した約300菌株の純化とベンチオカーブ耐性能の検討を行った結果,ベンチオカーブ耐

性能の差異よりはむしろ,農薬の利用が積極的に行われていることを推定させる!上帝状況を示す南棟

の存在が明らかとなったo (2)大型成層モデル水田土壌のミクロフロラ:成層の理化学的変化と極めて よく対応したミクロフロラ変動の要lkJをさらに詳細に実証.するために,程化学的性質を組み合わせた

4種類の小型成層モデルを組み立てて前年度の追試を行った｡ (3)次年度実施をf･定している令鴨利用

水川土壌の微生物フロラの予備調査を行い,土層の違いによって利用･非利用の間で差のあるこ･とを

推定させる結果を得た｡       (佐藤 匡)

植物の炭化物が火山灰土壌の腐植の供給源となっていることを明らかにするため,種々の温度条件

卜で植物から生成される炭化物の性質を検討した｡空気中の炭化では, 200-300度処理で生成物の炭

素含量が最大となった｡クロム酸に対する抵抗性と腐植酸含量も同様の傾rl-沌示した｡ X線凹折分析

およびNMR分析からは,炭化の過程はセルロース等の構造が炭素を｢卜｣､とした構造に変化して行く

ものと推定された｡したがって,火山灰土壌の腐植酸の供給源を高温に曝された植物体とすれば,そ

の過程に適した条件は, 300度付近で,空京の供給のある条件と推定される｡この温度は,火山灰土壌

から得られた炭化物と推定される粒子の熱的な性質とも一致した｡また,融雪剤散布の街路樹土壌に

対する影響の評価も行った｡      (佐藤 孜) -

15 -1996年1円∼12Jlの間に刊行した論文,著書の抄録

Hattori, T.: Advances in soil microbialecology and biodiversity. Edited by It. A. Samson, J. A.

Stalpers, D. van der Me主, and A. H. Stouthamer. Jn Proceedings of the E短hth

International Congress for Culture Collections. pl18-122, 1996.

1n soil microbial ecol(材y, One Of the m()st imp()tant unanswered (lueStions is: "Why does there exist a large discrepancy between the vlable count and dlreCt microscopic count ()f s()il bacteria?''T()wards this抑)al, asystematlC analysts Ofthe plati叩melhod ()Ⅰ` bacterial colony

formation on plate may be useful. Analysis of the colony formation of soil bacteria revealed i1

new approach t｡ this question. I constructed bactel･ial ecocollections of soils and invest厄ated phylogeny ()f isolates belonging to diffel ent SubgmupS ()f the collecti(-ns.

Wakao, N., H. Kumagai, H. Haga, T. Yasuda and T. Hattori : Analysis of arsenic-t()lerant

bacterial populations in a paddy field soil according t｡ rates ｡f devel()pment ()∩ snlid medial

J. Gen. Appl. Microbi()1. 41: 437-448, 1995.

Thecolony-forming process Of bacteria in a paddy fie一d soil on 1()0-f()ld diluted nutrient broth (I)NIi) plats containig As(Ⅲ) (250-1,OOOppm) was analyzed by the firsトorder reacti()n (F()R)

model. The process on plats with 250 ppm As(lII) was simulated by a superimposlti()n ()f thl ee FOR m()del curves, which are respecltively referred t() as c()mponent c()1()ny-fol`ming cul Ve (CCFC)

I, TT, ()r Ill. fiacterial is()late§ fr()m the 25() ppm As(HT) plates wel･e divided into three groups

according to CCFC, al()ngwhich each respective bacterium produced its colony. The three CCFC

groups showed diffel･ent trends of physiological p1-Operties: (1 ) the range of tr, which lS the watlng time f()r the appearance of the first colony of each si叩le population in the presence ()r absence of As(IH), (2) the range ()f the maximal tolerant As(I一l) concentratl()n for each lS()late and s()me

of its taxon()mic pr()perties. Twelve ()ut ()f 72 strains examined harb()red ()ne or m()re plasmids,

sugg,estinLr I()cati()n ()f As(lII)-tolerant genes on the chroml)S()mal lJNA.

Minamisawa, K., K. Ogawa, H. Fukuhara and J. Koga : Indolepyruvate Pathway for

lnd()1e-3-Acetic Acid Biosynthesis in Bradyrhizobilim elkanii. Plant Cell Physiol. 37: 449-453, 1996･

Indole-3-acetaldehyde (IAAld) was detected in the culture supernatant of

Brad_vrhlZOb7JLm (,lkami. I)euterium-labelled Ltryptophan (Trp) was incorporated into IAAld and

indole-3-acetic acid (1AA). suggesting that B. C/kaml produces IAA via IAAld from Trp･ In β･

e/kanit cell suspension, indo1-3-pyruvic acid (lPyA) was converted t() TAAld, and ex()genously

added lAAld was rapidly cnnverted t() IAA. Ful-therm()re, the activity or in°()lepyI-uVate

decarboxylase (lPr)C), which catalyzes the decarboxylati()n ()f IPyA t() produce lAAld and is a

key enzyme for IPyA patllWay, Was detected in B. elkLnu'l CelHree extl･aCt The ll'l)C activity depended ｡n Mg2+ and thiamine pyrophosphate. co fact()rs of decarb()xylatlOn This m(-untinLl

evidence strongly suggeststhat JAA synthesis occurs ∼,)'alPyA pathway(Trp - IPyA- lAAld - IAA)

in B c/kaTZZt.

Minamisawa, K. and K. Ebihara : Hydr()genase activlty ()fs()ybean nndules doubly infected with

Brlulyrhiz()bilim jaPt)nicum and B. (,lkanii. Soil Sci. Plant Nutr. 42: 917-92O, 1996･

Rhizobitoxine (2-amjn0-4- (2- amino- t'3- hydr()pr()p()xy卜lr(lns- but-.'i- enoic acid) is a phytotoxln

produced by some strains ()f Bra(/yrhlZ('blum species. In the previ()us report. rhizobitoxine

inhibited ∫/(, n〃抑ノSynthesis ()f uptake hydr('genase ln free llViniI B j〟fMjH.I/nt. In tllis study, we

16 -investigated the possibility that co-modulation ('f soybean by rhlZ')bitoxine-pl･Oducing (RT･ ) B. tJlk"nlZ and hydrogen-uptake positive (Hupl ) B jaP'nw･lLm may give rise to an inhibitory effect of rhizobitoxine on hydr()ffenaSe Synthesis in the symbl()tlC ass()Ciati()ns･ Hydrogenase activlty

increased llnear】ywith increasing bacteroid occupancy of Hupl strain･ In particular, slgnificant

hydr()genase activity was ()bserved even in the presence of rhizobitoxine- producing bacteroids.

This result indicated that rhizobit()xine pr()duced by B t,li"zm･Z. does not inhibit hydrogenase

synthesis of B. jab,"zzrz川l Hup+ strain in the doubly infected soybean nodule with both species.

Mistui, H･･ S･ Hasezawa, T･ Nagata and H･ Takahashi : Cell cycle-dependent accumulation of

a kinesin-like pr(,tein, KatIう/ C, in synchronized tabacco BY-2 cells･ Plant Molecular Biology 30: 177-181. 1996.

Immunobl(,t anaysis with antibodies prepared against highly purified recombinant truncated kinesln-like pr(,teins, Katli(5-249) and KatC(207-754), encoded by the katβ and katC

genes of Arabidopsis thaliana revealed the presence of a kinesinlike polypeptide, termed KatB /

C, in cultured tabacco BY-2 cells, The KatB/ C polypeptide cosedimentedwith microtubules in

the presence of a nonhydrolyzable ATP analogue and was released from mlCrOtubules in the

presence of ATP, both of which are characteristics ()f kinesin proteins. The amount of Katfう/ C polypeptide in synchrnn()us lうY-2 cells increased during M phase of the ce一l cycle.

Micl･｡tubule-based structures present ln Cells at M phase, such as the spindle and phragmoplast,

may be the site ()f acti()n ()i the KatIう/ C protein.

嗣く 究,遊橋催･‥ 根粒厨の′Ⅰ採するりポキチンオリゴサッカライドの波秩,化学とLll:物, 34‥

3451348, 1996.

Sat｡, K･ and SIB･Lee: Effect of glycine,glutamate, and glucose ()n proliferation ()f PCP

(pentachlorophenolトdegrading microorganisms in soil. Soil S°i, and Plant Nutr, 42 : 905-910, 1996‥

Pentachl()rophenol(PCP) was aerobically incubated in soll suspension in the presence

of some (,rganic c(,mp(,unds which may be utilized as a nutrient by micro()rganisms in sou

suspension･ A t(,tat vlable c(,unt of bacteria increased much greater in the presence ('fthe organic

c(Imp()unds than in the absence (,∫ th(,set Number nf Gram-negative bacteria changed similarly

to that of the total vlable bacteria･ On the contrary, PCP-degradingmicroorganisms did no

increase in the presence of the organic c()mpounds. r)egradation of PCP also declined after an

initial rapid disslpatlOn in the presence of theorganic compounds while it proceeded linearlvwith

the time-course in the absence of the c｡mpoundsI All the comp('unds were deifraded, and pH of

soil suspensions did n()t differ among different treatments.

Sat(), K : Effect of glucose on proliferation of PCP (pentachlor叩henol)-degrading

microorganisms in soil･ Soil Sci. and Plant Nutr. 42: 9111916. 1996.

1Jentachlorophen()1(PCP) was aernbically incubated in soil suspensl｡n in the presence

of dlfferent concentrations of glucose which may be utilized/as a nutrient by micl-OOrganisms in s(一il suspension･ A totalviable c(,unt ('f bacteria lnCreaed ace()rding to the increase ln the

c()ncentration ofglucose･ This increse also c()rresp()nded t() that of the glucose-utilizing bacteria.

Number of Gram-negative bacte一･ia was very small in the belirinniW ｡f the incubation of soil suspensi()n and it increased abruptly with incubation and changed simjlar】y als() I() that of the

total vlable bacterial On the c('ntrary, the increase in the number of PCP-degrading

17 --mlCrOOrganisms delayed in the presence of glucose and the higher the c()ncentration of glucose,

the more delayed the start of the increase. The delaying effect by the additon of higher

concentration ()f gluc()se was not observed in the presence of large amount of PCP because the large am()unt of PCP itself inhibited the proliferaton of the PCP-degrading microorganisrns･ The amount of C()2 evolved from the soil suspensions corresponded approximately t() that of glucose introduced and the PCP-degrading p-lCrOOrganisms started to proliferate acc()rding t() decline of C()i, evolution.

Menyah, M. K. and K. Sato : Survival of inoculant Bradyrhizobium jaPonicum in an Andosol･ Biol. Fertil. Soil. 23: 105-109, 1996.

The survival ()f an antibi()tic-resistant mutant of a commercial in()culant Bradyrhiz''bium jaPoni'･lim Strain, A1017ks, was studied ln a VOIcanic ash soil (Andosol) in comparison with a non-volcanic ash soil (Fluvisol) over a period of 84 Jdays.In a n()n-sterile s()il

system, the population decline in theAndosol (15% or 1.2 1ogunits)was largerthan in the Fluvisol

(6% or 0.54 log units). In both soils, however, the inoculant bradyrhizobium survived at fairly high

population levels after the period of incubation l1()Hand lO7 col(,ny-formi叩units (CFU)g 1 dry

soil in the Andsol and FluvISOl, respectively L In sterile c()ntr()1 S()il, viable bradyrhizobium cells

c()uld not be detected after 1 week ()fincubati()∩ in the And()sol, whereas in the Fluvisol populati()∩

of introduced bradyrhiz()bium was maintained throughout the period of incubation･ Overall changes in the populati()n of indigenos bacteria and fungi were also monitored･ However, no clear pattern ()f interaction between the inoculant Bradyrhzz()bizim jaf,(mlrZun and the indigen()us micr()bes could be identlfied. The anitibiotic-resistant mutant maintained its resistance in the

Fluvisol throughout the 3-month period of lnCubation, making it a useful m()del for conducting ec()logigal studies in the s()il,

Menyah, M. K. and K. Sato : A proposal for re-evaluatingthe most probable number procedure

for estimating numbers of Bradyrhizobium spp.Biol. Fertil. Soil. 23: 110-112, 1996･

The reliabHity of the m()st pr()bable number (MPN) method for estimating bradyrhlZJObial numbers was evaluated bv comparison with the plate count procedure. MPN

estimates increasedwith time of modulation scoring after seedling inoculation throug,h 6 weeks

of incubatl()∩. Ratios of MPN t｡ plate counts Increased as the bradyrhiz()bial cell suspension

concentration incl･eased. The MPN method could not detct Bmdyrhiz()bium jaPum(.tim numbers

at concentrations of 103 colony formi叩units (CFU) ml 1 and below. A proposal for re-evluating

MPN estimates is discussed.

Sato, K. and H-Y. Jiang: Gram-positive bacterial flora on the root surface of wheat (Triti(:um

〟(,stiI'um I,) grown under differnt soil conditions. Biol. Fertil. Soil. 23: 1211125, 1996･

we identified 108 Gram-p()sitive bacterial strains isolated from the root surface of

wheat gr()wn tlnder different soil c()nditi()ns･ The strains were divided intn four groups based (一m m()rpll()logica一 aTld physi()logica一 characteristics, but most appeared t() be corynef()rm･ The

taxon()mic position of the varinus groups was vet-ified by the guanlne + cyt｡Sine I)NA c()ntents

of the strains. In general, the ranges of these values agreed with those described f()r the respective taxonomic positions ln the literature, with a few exceptlrⅢS･ With s()il improvement the distrlbution of the various groups on the root surface changed, wlth the coryneform group

becoming dominant. This ilrOup Was further divided into five subgr()ups, according to cell wall

c()mp｡nents, cellulose-decomp()siti｡1-, and m()rphological chal･aCterStics, and were Identified t()

Lq,emus level. The distributi()n of these subgroups ()n the root surface of wheat did n()t alter wlth

一一一18 -S()il improvement. The genus Ar/hub(ir/(,Y. the dominant subgr()up, pred()minated in every plot

Sato, K. and HIY. Jiang: Gram-negative bacterial flora on the root surface of wheat (Triticum

aestiuum) grown under differnt soil conditions. Biol. Fertil. Soil. 23: 273-281, 1996.

We identified 161 Gram-negative bacterial strains isolated from the root surface of

wheat grown under different soil conditions. The strains were divided into seven groups based on maJ()r mOrphological and physiol()gical properties. Taxonomic allocation of the groups was verified by guanine + cytosine contents of DNA. Except for one group, which may be assumed

t｡ include bacteria belonging to the genera Flauobacterium and CytoPhage. the various groups were taxonomicalIy united. The distribution of the groups changedwith soil improvemenL

Pseudomonads pred()minated in unimproved soil, but Flat,obarferium and Cytof)haga spp. were pred()minant in the m()st improved soil. As all the strains were nun-fermentative by Hugh and

Leifs()n's test, APT 20NE identificati()∩ was applied. H()wever, many strains were misidentified

by this system, especially in the Tll(JT)()b(Lrtl,rium and Cyt()phaga spp. gr()up. Forec()logical studies,

the strains were classified t() species level by the APT 20 NE system and by the results of a

c()mbination of guanine + cyt()sine (mol粕)and isoprenoid quin()ne data. The pattern of distribution of the bacteria on the root surface of wheat varied at species level within one genus dependjng on soil conditions.

Yamamoto, H., K. Sato, A. Katayama, I. Watanabe, K. Inubushi, and K. Senoo: Recommended

tests for assessing the side-effects of pesticides on s()il microflora of paddy fields. Proceedings

of the 2nd International Symposium on Envir()nmental Aspects of Pesticide Microbiology (ed. by Anderson,J. P. E. et al) ISBN 90-56071004-5. Soc. ofEnviron. Toxic()1. and Chemistry (Brussels,

Belgium). 44-46, 1996.

Un projet de rec()mmandati()n est pr()pose p()ur testel 1es effets secondaires sul 1a

microflore des s()1s rizi占re. Quels processus et quels organismes sont les plus importants pour le maintien de la qualitさdu sol? Quelques concepts pour la sさlection des param占tres appropriさs p()ur l'占valuation sont d'abord discut6S. I.'effet du s6chage a l'air sur l'ammonofication, la min6ralisatlOn de la mati占re organique, la nitrificati()n, la d占nitrification, la cr()issance des algues, 1a fixati()n n()nsymbi()tique de l'az()te, la bi()masse microbienne sont retenus comme paramとtres a tester.

Sato, K.: Effect of possible dechlorinated compounds of the pesticide pentachlorophenol (PCP) on bacteria in soil. Proceedings of the 2nd lnternational Symposium on Envir()nmental Aspects of Pesticide Microbiology (ed. by Anderson, J. P. E. et al)ISBN 90-5607100415. Soc. of Environ.

Toxicol. and Chemistry (Brussels, fielgium). 51-52, 1996.

L'effet de quel(1ueS COmpOS占s d6chlor6s du pentachloroph占nol (PCP) sur la microflore du sol a 6t6 6tudi6. La prol()f6tation des celluled tol占rant ces compos6S, prise comme index d'effet, est suivie apres applicati()n. Parmi les compos占s testis, le 2, 4, 5-trichloroph6nol est le plus n()elf, 1e 2, 3, 4, 5-t占rachloroph6nol l'est moins et le 2, 4, 6-trlChlotop/h占nol trとs peu.

佐藤 匡:東北地jJ-における徴年物資材の試験状況とその結果. ｢徴牛物を利用した農業資材の評価｣

に関する研究.社団法人日本l二壌肥料学会. 1 -5, 1996.

学会での目頭発表,展示発表

南沢 究,伊沢 剛,二L朋｢,阪井 満,市毛秀則:ダイズ根粒菌超反復配列保イ7A株におけるDN

A再編成と遺伝(水平伝播 (第1報)超反復配列保有株の特徴とDNA再編成の証拠,日本 上壌

肥粁学会(4月3-5日,東京) 佃尺 剛,三卜朋子,阪井 満,南沢 究:ダイズ根粒菌超舶妄摘己列保有株におけるDNA再編成と 遺伝/-水平伝播 (第2報)挿入配列の特徴と分ffi,日本土壌肥料学会(4月315H,東京) 皆川律｢,磯田香保里,人什憲邦,献尺 究,五十嵐太郎,人山卓爾: gus一代謝産物のフェノール抽 出測定法によるgus一根粒菌株の挙動の解机 日本卜壌肥粁声会(4H3-5日,束京) 伊沢 剛,三上朋+,板倉 学,南沢 究:ダイズ根粒菌のI)NA再編成-jI;･L招貞城のマッピング, 植物徴/1-:物研究会(10月3-4日,東京) 南沢 究,伊沢 剛,遊橋健 -, Hf毛秀則,鈴木稚十:ダイズ根粒菌における根粒形成遺伝+の水平 伝達,植物徴/l二物研究会(1()lJ3-4日,束京) 竹川律f-, llJM信也,磯田杏保里,佐藤 孝,人件憲邦,人山卓軋 南沢 究,遊橋健･,赤尾勝･ 郎: l二項中におけるGUS標識根粒菌数の測定,植物徴′†物研究会(1()月3-4日,東京) 鹿野秀一一,三井久幸,服部 勉:草地L壌細菌群集における種構成の時間的変化,日本徴′f-:物′1三態学 会(11月16-17日,束京) 服部繁子,三拝久幸,鹿野秀 一,服部 勉: -L壌DNB細菌の食塩感受件とカルシウム要求性,日本 微生物/ti:態学会(11月16-17日,東京) 南沢 究,伊沢 剛,遊橋健-I,市毛秀則,鈴木雅子,三卜朋上 板倉 学:ダイズ根粒菌における DNAlヰ編成と根粒形成遺伝+の水1;-伝達,日本徴/LI物/I-:態学会(11H16117日,東京) 佐藤 Ll三,妾 紅英:小麦根面のグラム陽性細菌フロラ｡日本l二壌肥料学会1996年度入会(1996年4 月3-5日,束京) 小関 茶,佐々木l主市,佐藤 Lli.,小幡n希:人型成層モデル水lljの浸透判と物質の動態(1)開放系に おける物質の変化｡日本f-.壌肥料学会1996年度大会(1996年4月3 -5日,束Ij.,-)

Sat(), K∴ Effect nf possible dechlnrinated compounds of the pesticide pentachl()rophen()1 (PCP)

on bacteria in soil. 2nd International Symposium on Environmental Aspects of Pesticide

Micr｡biology (July. 4-ll, 1996, Beaune, France)

Yamamoto, H., K, Sat(), A. Katayama, Ⅰ. Watanabe, K. Inubushi, and K. Sen()().:Recommended

tests for assesslng the side-effects of pesticides nn s()il micr｡flora of paddy fields. 2md

lnternatinnal Symposium on Envi1-0nmental Aspects ()f Pesticide Microbi()1°gy (July. 4-ll,

1996, Beaune, France)

佐藤 匡:異なる椎類の土壌での資材試験の必要な理由の実例について｡日本f･_壌肥料学会公開シン

ポジウム｢徴/1:_物を利用した農業資材の現状と将来｣ (1∼)96年8 1123日,東京)