東北大学遺伝生態研究センター年報 1995
著者
東北大学遺伝生態研究センター
発行年
1995-03
i;コLIT
｣
挨 拶
本研究センターは,平成7年4日で発足8年目を迎えようとしています.私
どもの中心的課題は, ｢生態系における種の生活の遺伝的基礎｣の解明でありま
すが,平成7年には,ワークショップ｢遺伝生態の諸問題:｣を開催し,この
分野における到達点と今後の課題についての検討を行っております｡
分子lI二物的研究を中核とした今日の作物研究の目覚ましい進歩を地球環境中
の多様な生物の具体的な牛活の解明にどのように牛かすか､また地球史的な視
点と地球外遊Hlも含む人間活動の未来-の展望とを加味した｢臨界環境｣へど
う挑戦するか､この-一年の諸活動を通じて､こうした新しい問題意識を発酵さ
せつつあります｡
ここに､年間の研究業績のご報告をさせていただくと剛封こ､関係者各位
の-一層のご鞭桂とご支援をお願い致す次第であります｡
､打戊7年3月
東北大学遺伝生態研究センター長
服 部 勉
目 次
第一部 各部門の研究
生態生理研究部門
遺伝子生態研究部門
環境情報研究部門
臨界牛態遺伝研究部Pr]
生態システム研究部門(客員部門)
第二部 共同利用研究
ワークショッフ
共同利用研究
I GEシリーズの紹介
I SKシリーズの紹介
センター通信及びニュースレター-の寄稿
第三部 その他の研究活動
外国人訪問者等による特別講義及び特別研究会･--･-センターの大学院学/I:. ･研究/ト:等の名簿
センタースタッフ
41第一部
生態生理研究部門
本研究部門では､植物や微生物のそれぞれの樺に特異的な遺伝[-JI育種の発現と生態閃子との関わり
を主として研究している｡すなわち､徴/仁物から高等植物まで､すべてのlli物が有する特定の形態や
行動(能力)は､その/I-:物に組み込まれている遺伝+に基礎をもつが､その発現は光や垂ノ)､さらに
温度や湿度などその年物体を取り巻いている/r_態凶子によって大きな影響を受ける｡菌類や単細胞件
藻類などの徴!_l二物､それに野牛の高等植物を材料として､これらの遺伝了･発現に及ぼす/l三態.大l l･の影
響とその作用機作を､主として遺伝学的また生理学的〟法を用いて解析している｡
接合菌類に属し､光や車力などの外的要lJ;Hこ対して敏感に反応するヒゲカビ(Phycomyces)を用
い､今年度は次のような研究を行った｡ (1)ヒゲカどの細川包壁の亨:_戊分の -つであり､このカどの光屈
性や光形態形成などに重要な働きをしていると思われるキチン合成酵素遺伝子のクローニング｡ (2)追
伝子機能相補を利用した遺伝f･単離にイ7-効で､Li人DNA導入をHT能にするコスミドベクターの開発｡
(3)硝酸レダクタ-ゼ遺伝+をネガティヴ･セレクション･マーカーとした遺伝+タ-ゲッテイング系
の確､Lf:の試み｡ (4)野/I:.株及び高感度束JJfLLiJJ･_'l:_異変株における束)J屈性の解析とその屈性速度を制御し
ているパラメーターの解析｡ (5)接合の際に観察される細胞間接着繊維の電(一顕微鏡的解析｡ (6)日本学
術振興会外国人特別招-い研究員であるGalina Lazarovaとの共同研究で､糸状酵母( Sporobol()myces )
における光屈性の発見とその解析o そして(7)近畿入学の.キ凹元イi言助教授との共同研究､接合反応にお
ける細胞間情報交換機構の解析を行った｡ (人瀧 保､官軍 厚､ GalinaLazarova､山崎 裕､福
井 丈)
先端!1-:長をする糸状黄藻フシナシミドロ( Vaucheria)は光強度が増すと負光放任を示して強い光
から逃れる｡負光屈性が起こる光強度は種や生態的条件により変わる｡種々の/に哩的実験から､.細胞
先端での高強度青色光による急激なCa2十流入が細胞内Ca2+濃度を一時的にある臨界値以上に上げるーこ
とが負光Jtg･作の偵L*Jであることが分かった｡現在､細胞内Ca2+濃度を実測する方法を開発中である｡
青色光による先端年長や細胞内柚性の制御機構を調べるため､細胞骨格の形態的機能的変化を蛍光
抗体法を用いて調べている(山形入学･菱沼ら､広島入学･峰雪､人阪入学･永井らと協同)｡青色光
は細胞長軸に平行に走る微小管束を寸断し､その配向を乱した｡青色光刺激の変換過程におけるCa2+
や細胞骨格の関与を調査中である｡
淡水産フシナシミドロは汽水産種に比べ､耐塩性が低い｡耐塩性の違いは､ NaClの透過性と蓄積能
力の違いに起関するらしいことを､イオンクロマトグラフを用いて明らかにした｡ (片岡博尚)
ー 1一一年生草本の生活環は種召木眠が関与する発芽と発育棚が栄養成長から牛殖成長に転換する花芽分
化の二つの過程で制御されている｡様々な植物種のフェノロジーはこれらの過程が環境条件とどのよ
うな関わるかによって決定されている｡このようなf暮三活環制御機構の集川分化の解析をタネツケバナ
( Cardamineflexu〃sa /winter annual )の∫‡:.再地が異なる6集川(北緯25度から40度まで)を用い
て試みた｡
その結果､高緯度の集川ほど花成誘導に対して長日およびバーナリゼーション要求性が高く発育相
の転換が特定環境に強く支配されているが､北緯350より低緯度の集川ではそれらの要求性が非常に低
く発南柏の転換がサイズ依存であった｡ -jJ-､種子休眠の推移を高緯度集凹(北緯400)､中緯度(北緯
360)および低緯度(北緯250)の3集[1Jの種+を室温乾燥条件で貯蔵し採取時から一年間にわたって発
芽様式を経時的に調査した結果､高緯度集川では温度による休眠誘導反応が見られず､低緯度集団は
高温域で強い休眠誘導を示した｡中緯度集団は高緯度と低緯度集川の中間の発芽様式を示した｡
このように､高緯度集川の発芽には全く制御機構が機能していないが栄養成長から牛殖成長への転
換には強く温度と日長による制御機構が機能している｡対月朗加こ低緯度集L寸任は発芽が強く温度によっ
て制御されているが発育相の転換には全く制御機構が機能していない｡この機能分化は高緯度集団が
冬期の乾燥と低温に耐え得るロゼットを形成することを､低緯度集団では発芽時期を制御することに
よって他種との競合を避けることを叶能にしていることが考えられる0 (41-乗義雄)
1994年1月∼1994年12月に印刷発行された本研究センター職員の論文,
著書の抄録
Ootaki, T. : Phototropism of Phycomyces sporangiophores. J. Photoscience. 1 : 69-73, 1994.
Sporangiophores (spphs) of Phyc()myc∫ blake,Jeeanu5 are p()Sitively phototropic to
unilateral visible (blue) light over a range of fluence rates 10 9 to 1 W /m2. The maximal bending
angle is always 7()-75 0 from the vertical. Many mutants with abnormal phototropism have been
isolated. C｡mplementation tests revealed that the genetic grouping is completely consistent with
the phen｡typic classificati()∩ scheme, based ()∩ sensory resp()nses Other than th()se t() light. The spph of the pilob｡1()id mutant, the glr()wth zone of which gradually ceases elongation but expands spherically, and the β-car()tene-｡verpr()ducing mutant sh()w negative ph｡t｡tr()pism, in c()ntrast
to the wild type spph We hypothesized that the phototropic orientation of spph is determined
by the ratio of the maximal light fluence 1-ate at the proximal side to that at the distal side of the
spph. Based on this hypothesis, we found that the maximal bending anglewas larger in thin spphs
than in thick (mes, and larger in spphs c()ntaining smaller amount of β-carotene than in carotene-rich spphs. In additi()n to our hypothesis, gravitropic experments revealed that the maximal bending angle ()fthe wild type spph results fr()m a balance am()ngp()sitive ph()t()tr()pism,
negative gravitripism, and the opitical properties ()∫ the spph. F()r further advancement ()∫ this
study, We developed a mutant with a high proportion ｡f uninucleate spores, and designed an efficient microinjection method for obtaining transformants.
大瀧 保,官軍 厚,ガリナ ラザロバ:ヒゲカビ(Phycomyces)は重力刺激にどのように反応す
るか一重力屈性の研究の現状と問題点一口菌報 35 ･ 111-125, 1994.
Gravlty is one ｡fthe fact()rs guiding the growth in fungi. We summarize what is known
about gravitropism in Phycomyct,s sporanglOphore一一一One Of the most developed model svstems considering "stimulus percepti()∩ stlmulus transduction resp()nse" system in fungi.
Comparedwith response t() light, gravitropism in Phyc()my(:es appears to be less
effective in respect t() the latency peri()d and the speed ()∫ resp()nse. Maybe this is the reason why studies on gravitropism have been less intensive, resulting in obscure and s()metimes contradictory information on receptors and involved mechanisms.
There are several parameters influencing the gravitropic response : developmental
stage and diameter of the sporangiophore, absolute growth rate, ratio of differential growth･ The
interplay between gravlty and light is expressed in tw() ways: influence ()∫ light ｡n gravisensitivity
and tropic equilibrium when b()th stimuli are present simultane()usly.
Attempts t() dissect the mechanism of gravitropic response and to model its kinetics
inv()lve experiments in a micr｡gravity environment as well as application of centrifugal force.
The gravireceptor is suspected to be localized in thegrowth zone but has not yet been indentified.
Further progress in the gravitropic studies could be achieved using mutants with impaired ()r
enhanced of gravitational stimuli.
Lazarova, G., T. Ootaki, K. Isono and H. Kataoka∴ Phototropism in yeast : a new phenわmenon
to explore blue light induced respones. Z. Naturforsch, Section C. 49 : 751-756, 1994.
Although yeasts have been intensively Investigated in photobiology, directional
resp()nse ()∫ yeast growth to light never been observed. The present data demonstrate for the first
time phototropism in yeast, the basidiomycetous yeast SPorobol()myccs salmonicolor. The effective
spectral band is blue light - suggesting that a blue-light receptor similar to that in other plants is involved in yeast photophysiology. Further studies on yeast phototroplSm C()uld help identification of the photoreceptor and throw new light on the mechanisms ()f signal transduction
andresponse.
Ishiguri Y., H. Kudoh and S. Kawano : Effects of different photoperiods and chilling treatments
on growth and reproduction of Cardaminej7exuosaWith. and its ecol()giCalimplications. Plant
Species Bio1., 9 : 75-84, 1994.
Phenotypic variabliity ()f Cl171damlnej7exuusa (Cruciferae) was examlnd in response to
different lengths of exposure to low temperature (5cc) at the juvenile stage, and to two
photoperiod regimes (8 and 16 hrs daylengths) in the subsequent growth period. The results indicated that this species had a facultative chilling or long-day requirement for fl()wering. The
long-day and chilling treatments both caused an earlier onset nf stem internode elongation･ L(mger chitling treatments reduced the number ()f n()des and increased internode length under
b()th long and short ph()toperi()d regimes. Pr｡1()∩ged chitling treatments followed by long-day
photoperiod remarkably induced more numerous basal branches and inflorescences, as a result
producing more siliques. Remarkable rosette leaves were formed at the base of the main stem when partial chilling and the short-day treatment suppressed stem internode elongation. The
responses to chitling and long-day treatment closely resembled the synchronized floweringofthis
species in spring in the field. Delayed flowering under the sh()rトday treatment resembled
size-or age-dependent fl()Wering in late summer to autumn in the field p()pulations.
その他の刊行物
官署 厚:根の動力屈性とホルモン｡根-ンドブック 根研究会下り pp.63-64.
学会での口頭発表､展示発表
Ootaki, T. : Phototropism of Phycomyces sporangiophores. '94 Ann. Meeting of the Korean
SocietyofPhotoscience. (6月11日,韓国･太田市)
人瀧 促,宮等 厚, LIJ崎 裕:ヒゲカビ(Phycomy(:e∫)における横合反応と細胞間認乱 日本植
物学会束北支部第8lPJ大会(12月10日∼11口､福島)
宮笥 厚,大瀧 保:糸状菌ヒゲカどのキチン合成酵素遺伝f･の構造と発現｡日本植物学会第58回入
会(9日20-22日,札幌)片岡博路'J :フシナシミドロでrd川寺に見られる垂直と､I'一行の2種の偏光),117.件｡日本柄物LtiT型学会(3 H
28-30日,つくば)高橋文雄,菱沼 拓,片岡博尚:黄緑藻フシナシミドロにおける細胞骨格o 日本植物学会第58回入令
(9月20-22日,札幌)高橋文雄,菱沼'仏,片岡博尚:フシナシミドロの側枝形成時における微小管配llnI｡日本柄物学会東
北支部会(12月10日∼11日,福島)
石乗義雄,工藤 洋,河野昭一-･ :タネツケバナの口長反応性における地理的集団分化｡日本植物学会
第58kp]大会(9月20-22日,札幌) - 4適応生態研究部門･
当研究部門では､耕地生態系を含む/I･:態系に存在する植物の遺伝イ･的変異を解明し､樗々の環境ス
トレス-の適応に有用な遺伝了.資源の開発に資すると共に､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｡平成6年度に得られた成果及び次年度以降-の展望は次の通りであるo
地球外環境における植物生再の問題点を探る手段として､重力に対する正常な反応を失ったイネの
変異系統を用いて研究している｡重力刺激による植物の屈曲反応には植物ホルモンのオーキシンが関
与しているとされるので､この変異系統(もつれ亀ノ尾)をJL-.常な系統(亀ノ尾)と比較して内生オー
キシンの含量を調査したo 屈曲反応は植物のエージに依存するので､変異系統がまだ重力刺激に反応
するステ-ジと反応しなくなるステージの2｢ロ1に渡ってオーキシン量を比較した｡前者の時期にオー
キシンは変異系統においてⅠ｢常系統の約倍呈検出され､後者の時期には両系統間に差異は検出されな
かった｡更に検討を要するが､今のところこの変異系統の重力刺激不感受性の原因としてオーキシン
含晃の差異が関与する吋能性は少ないのではないかと判断される｡ (菅 洋､高橋秀幸､阿部清美)0
植物の根に水分の多い方を感知して屈曲する性質すなわち水分斥副生が存在することを､重力定則-!仁を
失ったエンドウの突然変異系統を用いて始めて科学的に証明できたが､今年度はその機作の解明のた
めの研究を始めた｡水分屈性の存在をよりL由二接的に証明するため､根の先端や伸長部に浸透圧の異な
るソルビトール溶池を含む寒人小片を付着させる実験系を確立した｡これにより水分屈性の存在がよ
り直接的に証明され､さらにその機作を研究するための方策が確立された｡水分屈性の発現にカルシ
ウムが大きな役割を演じていることなどが明らかにされた｡ (高橋秀幸､菅 洋､高野 守)｡
一方､チャンバー内の空気湿度に勾配を作って根の水分屈性を調べる実験系を用いて研究した結果
(東京農工人草との共同研究)'1根の水分屈性においては湿度差が根の先端で感知され､これによって
伸長組織の水伝導度と細胞壁の伸展係数が影響を受けて屈曲が起こるものと考えられた｡ (平沢If:_､
高橋秀幸､骨 洋､石原 邦)｡
近未来に想定される気候温暖化が植物群落や生産性に及ぼす影響を知るため､亜熱帯相当高温環境
下のミニシバ型草地の第5年日の動態を検討した｡構成種の生育は､高温継続区のシバの減少､アキ
メヒシバ､シロツメタサの増加､また初年戸外区のシバ､シロツメタサ共存体制の存続と昨年同様に
推移していた｡
資源植物保全と生産機構についての研究では､オーストラリア東北部における飼料マメ科樹の多目
的利用実態を調査した｡深根性のマメ科樹は､浅根性の飼草類と異なり乾季における飼料生産に､ま
- 5 -た立体的生産構造の展開に大きく寄与することが明らかとなった｡オセアニア地域に分布するシバ
(zoysia)属の2種の生態についてみると､ニュージーランド南島のZ. minimaは海浜砂地における
先駆種として､また東部オーストラリア海岸のZ. macranthaは最前線のSpimfix種と内陸部のCynodon
種の中間に生育城をもつことが判明した｡ (庄司 舜-)0
植物の発芽期における器官の形態形成の可塑性は､環境適応上秘めて重要であり､興味ある課題を
内蔵している｡禾本科植物の中茎､第一節間は樺7-が地中深く位置した時に､ ′壬三長点を地上近くに押
し上げるため重要な役割を果たしている｡本年度はトウモロコシの巾茎伸長について､エチレン､二
酸化炭素などの役割を研究し､その縦方向の伸長が赤色光中でエチレンと二酸化炭素によって促進さ
れることを発見した｡さらにこの両者は協力的に働くことも確認された｡しかし､興味あることにこ
の中茎の伸長は完全暗黒下ではエチレンにより阻害され､二酸化炭素はそのエチレンの阻害作用に桔
抗した｡ (西沢武明､菅 洋)0
1994年1月∼1994年12J=こ印刷された本研究センター職員の論文,
著書の抄録
Takahashi, H., M. Kimura, H. Suge and T. Saito : Interactions between vernalization and
photoperiodic effects on the flowering of turnip plants and their varietal differences･ J･ Jap･
Soc. Hort. S°i. 63 (1): 99-108, 1994.
The interactions between vernalization and photoperiodic effects on the flowering ｡f
I2 turnip varieties were examined under controlled environment. Seedlings ()f all varieties bolted
and flowered under a long-day condition ()f 24 h day-length (LD) when the germinated seeds had
been per-exposed t() low temperature at 3 ℃ (TノT) for 30 days. Under the LD c()ndition, the ratio
of flower formati()n ()f all the varieties except for `Tennojl'slgnificantly decreased as the duration
of LT treatment was shortened to less than 7 days. With LT treatment of more than 14 days, 80
to loo‰ of plants in all varieties formed flower buds under LD. When the seedlings were subjected
to elther LT and subsequently grown under a short-day condition of 8 h dayllength (ST)) or LD
without LT treatment, the number of plants that formed flower buds substantially decreased. Furthermore, the effect of seed vernalization was counteracted by subsequent SD conditions
under which the vernalized seedlings were gr()wn thr()ugh｡ut the experiment. Namely, flower
formation and boltingofthe vernalized seedlingswere significantly inhibited when the LT-treated seedlings were subsequently grown under SD. The flowering responses of turnip plants to
temperature and photoperiod significantly differed among the varieties used･ We have classified
the turnip varieties into five groups. `TennoJi', `Shog｡in', and `Hakatasuwari'strongly responded to the single treatment of either LDorLT, resultingin a high ratio offlowerformation (Type I ),
1
whereas either treatment hardly induced the formation of flower bud in `Yorii', `Hinona , `ohnobeni', and `Kanamachi'(Type II ). `Ohyabu', `Ohmi', and `Atsumi'showed an intermediate degree of flowering ratio between the Type I and II in reponse to either LD or LT treatment (Type llI ). In `Yamauch', LD itself did not induce flower formation of non-vernalized plants, but
the LTcaused a high ratioofflowerformationeven underSD (TypeⅣ ).Bycontrast, `Narusawana'
- 6 -showed a substanti()al ratio of flower formation due to LD without LT treatment, while the seedlings treated with LT did not flower under the f()llowing SD in this variety (Type V ). Thus,
the flowering ()f turnip plants is dramatically influenced by photoperiod as well as by temperature, and the responses to the tw() factors significantly differ among the varieties.
Abe, K., H. Takahashi and H. Suge : Graviresponding sites in shoots of nomal and `lazy'rice
seedlings. Physiol. Plant. 92 : 371-374, 1994.
We have examined the graviresponding sites in the shoots of seedlings of rice ( Oryza
sati7)a L) and their relation to the agravitropic growth of a `lazy'line. The graviresponding sites
｡f the seedling shoots of a japonica type of rice, cv. Kamenoo, shifted from the mesocotyl/cole-optile region to the leaf-sheath base when the shoots grew in the dark. A lazy line of rice,
1azy-Kamen()0, showed gravicurvature in the mes()cotyL/coleoptile region at the early stage of
growth, but eventually 1()st its graviresp()nse as the seedlings grew. The loss of
gravi-responsiveness of lazy-Kamenoo was attributed to a reduced response ()∫ the c()1eoptile and a
diminished response of the leaf-sheath base to gravity. Later, the leaf-sheath base of
lazy-Kamenoo become gravitropically incompetent, causing agravitr()pic growth of the shoots. Thus, shoots of lazy-Kamen()o lose graviresponsiveness in an organ-dependent fashion ･
Takahashi, H. and T. K. Scott : Gravityィegulated formation of the peg in developing cucumber seedlings. Planta 193 : 580-584, 1994.
It has been pr()posed that peg formation in the vascular transition region (TR zone) between the hypoc()tyl and the ro()t in Cucurbitaceae seedlings is a gravimorphogenetic
phenomen()n. Initiation of the peg became visible 36 h after imbibition when cucumber ( Cucumis satiuus L. cv. Burpee Hybrid II ) seeds were germinated in a horizontal position at 24 0 C in the
dark. Simultaneously, sedimented amyloplasts (putative statoliths) Were apparent in the sheath cells surrounding the vascular strands, and in the cortical cells immediately adjacent to them,
in the TR zone. In contrast, the other cortical cells, S()me of which were destined to develop into
the peg, contained amyl()plasts which were ∩()t sedimented. These results suggest that the
graviperception mechanism for peg formation may be like that()fstatoliths in shoot gravitr()pism.
By 48 h following imbibition, the cells of the TR zone stiH had sedimented amylr)plasts but had
lost their sensitivlty tO graVlty, possibly because of their maturation.
Takahashi, H∴ HydrotroplSm and its interaction with gravitropism in roots. p′ant and S〇･日65 :
301-308, 1994.
We have studied hydr()trr)pism and its interaction with gravitroplSm in agravitropic
r()ots of a pea mutant and normal roots of peas ( Pi∫〟m satit'um L.) and maize ( Zea maysL.). The interaction between hydrotr()pism and gravitr()plSm in normal ro()ts ()f peas were also examined by nullifying the gravitropic response on a clinostat and by changing the stimulus-angle for
gravistimulation. Depending on the intensity of both hydrostimulation and gravistimulation,
hydrotroplSm Of seedling roots strongly lnteraCt With one another. When the gravitropic response
was reduced, either genetically or physiologically, the hydrorropic response of roots became more
unequivocal. Also, roots more sensitive to gravlty appear tO require a greater moisture gradient
for the induction of hydr()tropism. Positive hydrotroplSm Of roots occurred due to a differential growth in the elongati()n zone ; the elongation was much more inhibited ｡n the moistened side than on the dry side of the roots. It was suggested that the site of sensory perception for
hydrotropism resides in the root cap, as does the sensory site for gravitropism. Furthermore, an
ー 7 -auxin inhibitor, 2, 3, 5-triiodobenzoic acid (TIBA), and a calcium chelator,
ethyleneglyco1-bis-( β-aminoethylether)-N, N, N', N'-tetraacetic acid ethyleneglyco1-bis-(EGTA), inhibited both hydrotropism and
gravitropism in roots. These results suggest that the two tropisms share a common mechanism in the signal transduction step.
Abe, K., H. Takahashi and H. Suge : Localization of cells containing sedimented amyloplasts
in the shoots of normal and lazy rice seedlings. Biol. S°i. in Space 8(4): 221-227, 1994.
We have examined the localization of the cells containing sedimented amyloplasts
(putative statocytes) and its relation to the graviresponding sites in the shoots of n()mal and lazy
rice seedlings. All graviresponsive organs of the shoots ｡f normal rice seedlings, the mes()C()tyl, the coleoptile and the leaf-sheath base, were found to possess the statocytes. This is the first
indication that mes()cotyl senses gravity by its ()wn cells in inducing gravitr()pic bending in rice
seedlings. In lazy-Kamenoo, although the sh()()ts lt)st their gravitr()pic respt)nse with the advance
- of age, sedimentation of amyloplasts itself might not be attributable to the agravitropic growth
of the shoots because, including those of the leaf-sheath bases that had lost their response to
gravlty, the sedimented amyloplasts appeard to be identical to those of normal Kamenoo and alsr) of younger seedlings of lazy-Kamenoo whose gravitropism is still apparent.
Suge, H. and T. Kusanagi : Ethylene and carbon dioxide in the regulation of initial growth
in Sagittaria trlfolia L Weed Res., Jap. 39 : 237-242, 1994.
1nitial growth of Sagittana trlfolia shoots in darkness from tubers was controlled by
ethylene and carbon dioxide. The initial growth was reduced in air from which ethylene and/or
carbon dioxide had been removed, Compared to growth in air where endogenously ev()lved
ethylene and carbon dioxide were present. Growth was maximum in air where both ()f ethylene and carbon dioxide were present. The ethylene concentrati()n that induced maximum gr()wth was
lOFILI/1.
Takahashi, H. and H. Suge : Gravitropicmutants in studyingplantgrowth in space. Advances
in Space Biology and Medicine. JAI Press lnc. Vol, 4 : 127-158, 1994.
Ⅰ. Introduction
II. Mutants in Studying Gravitropism A. Statoliths in Gravitropism
B. Growth Substances in Gravitropism lll. Mutants in Studying Hydrotropism
A. Hydrotropism and Its Interaction with Gravitropism B. Hydrotropism and lntenslty Of Gravistimulation C. Hydrotropism and lntenslty Of Hydrostimulati()n Ⅳ. Mutants in Studying Other Plant Movements
A. Other Tropisms and Circumnutati()∩ B. F()rmatir)n and Opening ()f Plumular H｡｡k V. Simulation of Space Experiments by Using Mutants
A. Growth Orientation in Space B. Seed Pr()duction in Space Ⅵ. Conclusions
References
- 8 -高橋 秀幸(分封l執筆) :根の-ンドブック｡森円 茂紀･阿部 淳 編,根研究会発行, 1994.
本吉は､ -ンドブック式に17･馴こ解説された根の一?･･術吉であり､以下の13章から構成されているo第 1草 根の構造､第2農 相の作肖､第3寮 根と植物ホルモン､第4草 根の脚隼と伸長ガrl)1､第5 章 根系の形成､第6章 いろいろな根系､第7草 根と環境条作､第8卓 根と栽培管稚､第9草 根の遺伝･分f-JI･:物学､第10草 根の機能､第11草 根周､第12草 根系のモデル･竹丘解析､第13草 根系調査jJ'は｡この小の第3章および第4章において､根とアブシジン醸(p.55-56)､根とエチレン (p.57-58)､雌の重力fttiJl生(61-62)､根の接触在副生(p.73-74)､根の水分屈性(p.71-72)､の5 ffiHについて分担執筆したo内藤 俊彦,西条 好辿, ll･:司舜･ :峰山高原のチマキザサ(Sasapalmata).草地生態,第30号
12-27,1993. 兵庫胆人inHAJ町峰山高原(標高1,02()m)におけるカラマツ植林地内防火滞(毎年刈り払われる)の チマキザサについて調査を行った｡チマキザサの農長､腰幅､射lTT一棟および柴乾燥奉呈との間には.E;い相関が認められ､防火帯のチマキザサは柴の小判化や押掛女の増加によって連年の刈り払いに対応し､
個体群の維持を計っていると推察された｡
その他の刊行物
骨 洋:氏族の生存賭け成立一食文化の視点｡荘内日報1月23日号
菅 洋:植物｡宇宙環境利用の展望,宇宙環境利用推進センター: 119-144.
菅 洋:花成刺激による開花の誘導｡バイオサイエンスとバイオインダストリー,バイオインダス
トリー協会: 52巻5号7-8. 菅 洋:にっぽん育種物語一日本人が育てた/I-:物たち-イネ｡遺伝, 48巻6 U,,･63-67.菅 洋:く脚注)ーL藤吉郎兵衛の｢Hの丸｣｡荘内日報12月11日号
高橋 秀幸･菅 洋:ウリ科植物の垂)J形態形成二キュウリ芽!l三えのペグ細胞の発達と垂ノ]感受機
構｡宇宙利用シンポジウム,宇宙科学研究所p67-68, 1994.
高橋 秀幸･菅 洋･小柳 敦史･平沢 正･石原 邦:宇宙環境下における植物の定位反応:
根の水分屈性発現機構｡宇宙利川シンポジウム,宇宙科学研究所p69-71, 1994.
高橋 秀幸:車JJが植物の形を決める｡最新科学論シリーズ24,形の科学,学習研究社p1261131,
1994.高橋 秀幸:根の環境応答と屈性｡農業および園芸,養賢堂 69:423-428, 1994.
高橋 秀幸:根の水分蛸性は機能するか｡根の研究,根研究会3(4) : 991102, 1994.
一 9学会での口頭発表,展示発表
高橋 秀幸:ウリ科植物の重力形態形成｡第16回宇宙ステーション利郎h句ワークショップ(1月18-19日,東京)高野 守･高橋 秀幸･菅 洋:/ィンゲン(PhaseolusuulgarisL.)の茎の空洞化現象に及ぼす
接触刺激とジべレ1)ンの影響｡日本植物!上理学会年会(3月28-30El,つくば市)
小柳 敦史･高橋 秀幸･菅 洋‥コムギの根の水分屈性とその品種間差異｡日本作物学会春期大
会(4月6-7日,東京)I.i,-一沢 止.･高橋 秀幸･菅 洋･小柳 敦史･石原 邦=エンドウの根の水分屈性における生長
反応の解析｡日本作物学会秋期大会(8月28-29日,札幌)
高野 守･高橋 秀幸･菅 洋二インゲン(PhaseolusuulgarisL.)の茎の空洞化現象における
ジベレリンの作用｡植物化学調節学会(10月13-14日,和光市)
小柳 敦史･高橋 秀幸･菅 洋:コムギ種了一根における水分屈性および重力斥副生の品種間差異｡
日本宇宙!1-:物科学会第8担1大会(9月16-17H,奈良)
阿部 清美･高橋 秀幸･畑田 清隆･菅 洋:イネ｢もつれ亀の尾｣の轟ノJ屈性と内生オーキシ
ン含量｡日本宇宙生物科学会第8回大会(9月16-17日,奈良)
高野 守･高橋 秀幸･菅 洋‥根の水分屈性におけるカルシウムの役割｡根の研究会(11月5
日,東京)
Takahashi, H∴ Significance of long duration space experiments on plant grnwth･ International
symposium for Promoting Applications and Capabilities of the Space Environment (Oct･ 3ト
Novこ1, Tokyo)
高橋 秀幸･菅 洋:ウリ科植物の重力形態形成:キュウリ芽牛えのペグ細胞の発達と重力感受機
構｡宇宙利用シンポジウム(10月9-lou,東京)
高橋 秀幸･菅 洋･平沢 正･小柳 敦史･石原 邦‥宇IEh'環境卜における植物の定位反応二根
の水分屈性発現機構｡宇宙利用シンポジウム(1011 9-10口,東京)
-10 -･ 10 -･遺伝子生態研究部門 10 -･
当研究部門では､ ｢人為的に遺伝子を改変した植物および徴/I-.物の生態系における動態｣の基礎的研
究を進めている｡本年度は以下のような研究を行った｡
環境ストレス耐性植物の作出と遺伝子発現:突然変異体の選抜; E IあるいはEMS処坤によって
得られたイネとトウモロコシの5-メチルトリプトファン(5MT)耐性株のアンスラこル酸シンタ-ゼ及びトリプトファンシンタ-ゼ遺伝子の発現について検討したところ､突然変異体のアンスラニル
酸シンタ-ゼの遺伝子の発現量がコントロール植物のものより高いことがわかった｡細胞質突然変異
による薬剤耐性株を作出するために､種々の突然変異誘発源について予備的実験をおこなった｡培養
細胞のソマクローナル変異を解析するために､トウモロコシの細胞分裂後期の染色体を観察したとこ
ろ､種々の染色体の構造変異が認められた｡
細胞融合による体細胞雑種の育成とその遺伝子解析; 5MT耐性のイネとニンジンの体細胞雑種の
5MT耐性機構について検討したところ､その耐性はイネ由来の遺伝子によるものであることが明ら
かになった｡細胞融合による遠縁異種間の遺伝子交換の可能性を探るために､材料の選定を試みてい
る｡植物の形態形成に関する生理学的･分子生物学的研究;イネ低温感受性(クロロシス)品種は低温
(15oC)暗崇下でタロロシス変異を起こし､これは単一一遺伝子により調節されている｡この品種の低
温時崇条件下における色素体分化を調べた結果､エチオブラスト形成の阻害が電子顕微鏡観察により
明らかになった｡また色素体DNAにコードされる遺伝子の転写に関してもいくつかの異常が認めら
れた｡
食用アスパラガス( Asparagus oNicinalis L. )は雌雄異株柄物であるが､系統的に近いアスパラガ
ス属植物の多くは雌雄同株である｡このアスパラガス属植物に見られる性分化を系統学的に解析する
ための基礎的研究として食尉アスパラガスの葉緑体DNAを抽出しクローニングを行い､制限酵素地
図を作成した｡また数種のアスパラガス属の葉緑体DNAの制限酵素切断パターンを比較した結果非
常によく類似していることから､アスパラガス属植物は系統的に非常に近いことがわかった｡
また食用アスパラガスの性決定因子の探索のためにRAPD法により雄雌間差を見たところ､異なる
バンドパターンが得られた｡現在この異なるバンドが雌雄間差か個体間差かを検討中である｡
(木坂広明､木坂真由美､吉田理一郎､李 柴玉､アントニオ･フルミニヤン･ジュこオル､大堀雅
子､鈴木良子､妾 権圭､菅野 明､亀谷寿昭)
遺伝子改変微生物の生態とその利用: -クサイ軟腐病の生物的防除法の確立をめざして研究を進めて
いる.優れたfl三物防除剤を開発するために､新たに360菌株を採集し通性テストの結果､有望な数菌株
-ifl -が見つかった｡次に､生物防除剤としての利用を目的に作出した3南棟のErwinia car()i()u()ra subsp.
carotouoraの非病原性変異菌より､
I)フアンピシン耐性菌を分離したo これらの耐性菌を使用して-クサイ種子のバクテリゼイションを行い､は種後から収穫期まで定期的に-クサイ根圏および菓両に
おける添加処理丙の動態を追跡した｡処稗博は発芽後ただちに√一葉へ移行し､は種1か月後に葉面の
歯数は1株当たり104のレベルに連する/が､その後漸減して収穫期には101-103となった｡一･方､は種
2 -3週間後､処理菌は-クサイ根系のほぼ全体に移行しており､根園の菌数は1個体当たり105-106で
あった｡しかし､収穫期には101-102のレベルにまで減少した｡収穫期まで処押菌がJti存していること
から､病原力を除き野性株の形質を保持した変異菌を作出することができれば､バクテリゼイション
は防除剤の簡易な施用法として利用できることが示唆される｡
1994年1月∼1994年12月に印刷発行された本研究センター職員の論文,
著書の抄録
Kisaka, H. and T. Kameya, : Production of somatic hybrids between Daucus car()ta L and
Nicotiana tabacum. Theor. Appl. Genet. 88 : 75180, 1994.
Pr()toplasts of a kanamycin-resistant (KR, nuclear genome), streptomycin-resistant
(SR, chloroplast gen()me) and chlorophyll-deficient (Al, nuclear genome) Nil()ti(IFl(1 tabarum
(KR-SA) cell suspension cultures or X-ray-irradiated mesophyll prot()plasts ()f Kanamycin-and
streptomycin-resistant green plants (KR-SR) were fused with p一ot()plasts ()f a cytoplasmic
male-sterile (CMS) Daucus carota L cell suspension cultures by electrofusion. Somatic hybI-id plants were selected for kanamycm resistance and the ability t() produce chlorophylL Most of the
regenerated plants had a normal JJ. (･〟r"ta morphology. Callus induced from these plants
possessed 23132 chromosomes, a number lower than combined chromosome number (66) of the parents, and were resistant t() kanamycin, but they segregated for streptomycin resistance, which indicated that N. labaclim Chloroloasts had been eliminated. Genomic I)NA from several regenerated plants was analyzed by Southern hybridizatlOn for the presence ()f the ne｡mycln phosphotransferase gene ( NPT II ) ; all of the plants analyzed were found to contain this gene･ Mitochondrial (mt) DNA was analyzed by Southern hybridization ()f restriction endonuclease
digests of mtDNAwith two r)NA probes, PKT5and (I(Jx II･ 'me results showed that the two plants
analyzed possessed the mitochondria of L)I (･〟γ')tat These results demonstrate that the regenerated
plants are interfamilial s()matic hybrids.
Kisaka, H., H. Lee, M.Kisaka, A. Kanno, K. Kang and T･ Kameya, : Production and analysis
of asymmetric hybrid plants berween monocotyledon ( Oryza satiua L) and dicotyledon ( Daucus
carota L.). Theor. Appl. Genet. 89 : 3651371, 1994,
Asymmetric hybrid plasts were obtained from fused protoplasts ()f a m()nocotyledon
( C)ryza satlVa L. ) and a dicotyledon ( Daucus t･arotaL. ). X-ray irradiated prot()plasts isolated from
a cytoplasmic male sterile (cms) carrot suspension culture were fused with iodoacetoamide-treated protoplasts isolated from a 5-methyltryptophan (5MT)-resistant rice suspension culture
by electrofusion･ The complementary recovered cells divided and formed colonies, which were
12 -then cultivated on regeneration medium supplemented with 25 mg/ 1 5MT to eliminate any escaped
carr()t cells. Somatic hybrids were regenerated fr()m 5 of the 5MT- resIStant col()nies. The m｡rphologies of most ｡f the regenerated plants closely resembled that ()f the parental carrot
plants. A cytological analysis of callus cultures induced from these plants indicated that most
of the cells possessed 20-22 chromosomes and were resistant to 5MT. An isozyme analysts revealed that several regenerated plants had the peroxidase is()zyme patterns of both parents.
A Southern hybridization analysiswith non-radioactively labelled DNA fragments of the rgpl
gene showed that regenerated plants had hybridzing bands from both rice and carr()t. Chl()roplast
(cp) and mit()chondrial (mt) DNAs were also analyzed by S()uthern hybridizati()∩ by using several
probes. CpDNA patterns of the regenerated plants were indistinguishable from those of the carr()t parent. However 1 of the regenerated plants had a novel band pattern of mtDNA that was not
detected in either of the parents, indicatlng a possible recombination of mitochondrial genomes.
Watanabe, N., M. Nakazono, A. Kanno, N. Tsutsumi and A. Hirai, : Evolutionary variations in
DNA sequences transferred from chloroplast genomes to mitochondrial genomes in the
Gramineae. Curr. Genet. 26 : 512-518, 1994.
The transfer ()∫ fragments ()f DNA fr()m chl()roplast gen()mes to mitochondrial gen()mes is considered t() be a general phen()men()∩ in higher plants. In the present study, Southern
hybridization, together with amplification by PCR and DNA sequencing techniques, was used
to examine the regions homologous to chloroplast rps 19 in the mitochondrial genomes of several
gramineous plants. In all the mitochondrial DNAs from the gramineous plants examined, except
for that fr()m wheat, the transferred fragments of chloroplast DNA were found t() be maintained
and the same junctions ()f mitoch()ndri()∩-specific and chloroplast-like sequences were found at
one terminus. This finding indicates that the transfer of the chl()roplast sequence ()Ccurred in the
distant past during the evoluti()n of gramineous plants. Subsequent analysis revealed that the
fragments had been vari()usly rearranged among species with respect to the Other terminus.
Consldering the current diversity of this one particular transferred fragment of chloroplast DNA,
we pr()pose that chloroplast-derived DNA sequences that have lost their original functions tend to be rearranged during evolution in mitochondrial genomes.
Nakazono, M., A. Kanno, N. Tsutsumi and A. Hirai: Palindromic repeated sequences (PRSs)
in the mitochondrial genome of rice : evidence for their insertion after divergence of the genus
Oryza from the other Gramineae･ Plant Moll Biol･ 24 : 273-281, 1994･
We have identified a family of small repeated sequences (from 60 to 66 bp in length)
in the mitochondrial gen()me of rice ( Oryza satiua cv. Nipponbare). There are at least ten c()pies of these sequences and they are distributed throughout the mitochondrial genome. Each is
potentially capable of forming a stem-and-loop structure and we have designated them PRSs
(palindr()mic repeated sequences). Their features are reminiscent of the small dispersed repeats in the nit()chondrial I)NA (mtI)NA) of some lower eukaryotes, such as Sacchar()myces cereuisiae,
Neur(JsP(Jr() (,･raJs〟 and Chlamyd()m()nag reinhardtii. Some of the PRSs rice mtDNA are located in
the intron of the gene for ribosomal protein S3 ( rps3) and in the flanking sequence of the gene
for chloroplast-like tRNAAsn ( trnN). An analysis of PCR-amplified fragments of these regions fr()m
the I)NA of some Gramineae suggests that the PRSs were inserted into these regions of the Oryza
mtl)NA after the divergence of Oryza from the other Gramineae.
13 -その他の刊行物
菊本敏雄:牛物防除--クサイ軟腐病を中心に- :東北地JJAにおける作物病害研究の歩みと展望(日
本植物病理学会東北部会創立30周年記念誌)鶴岡印刷株式会社: 223-226, 1994
その他の記事
Toriyama, K., T. Kameya and K. Hinata, : Somatoc hybridization between Brassica and Sinapis･
In : Bajai, YPS(ed) Somatic hybridization in crop impr()vement I" Biotechnology in
Agriculture and Forestry 27. Springer-Verlag, 334-341, 1994
学会での口頭発表,展示発表
妾 権圭,菅野 明,亀谷毒昭:ジベレリン/l三合成阻害剤(Uniconazol)によって発現するトウモロ
コシのcDNAクローンの単離及びその特徴｡日本育種学会第85回講演会(4月2-3日､東京農l二
人)
木坂広明,李 孝淵,木坂真由美,菅野 明,妾 権も 亀谷毒Hli:イネとニンジンの科間体細胞雑
種植物の解析｡日本育種学会第85lIiJ講演会(4月2 -3口､東京良し人)
李 菓玉,菅野 明,亀谷毒Hli :アスパラガス(Asparagusofficinalis L.)葉緑体DNAのクロー
ニング及び制限酵素地凶｡日本育種学会第85回講演会(4日2-3日､束京農⊥大)
妾 権圭,佐野 浩,亀谷寿昭:トウモロコシのGTP結合タンパク遺伝+の特性｡日本育種学会第
89回講演会(10月9-10日､宮崎大)
李 孝潤,輩 昌休,林 容杓,金 東吉吉,闇 庚深,亀谷劃Ji:ホースラデッシュにおけるトーモ
ロコシのトランスポゾン導入によるAC/DC形質転換体の選抜｡日本育種学会第89凹講演会(10月
9-10日､宮崎大)丹羽 毅,菅野 明,堤 伸浩,平井篤志:オオムギ葉緑体DNAの制限酵素地図と遺伝子地r3(1｡円
本丙種学会第89回講演会(10月9-10円､宮崎人)
14 -･環境情報研究部門･ ･
本研究部門の目標は､微生物を中心とした土壌環境の動態を遺伝牛態の立場から解明する基礎を構
築することである｡今年度から､大学院博士課程で分子生物関係の研究を行なった三井久幸氏が本部
門に参加し､遺伝生態的立場が強化された｡新しい陣容を生かし､長期的展望をつくりつつある｡本
年度に取り組んだ主要な研究は､以下のようである｡
微生物遺伝生態の基礎づくり:(1)昨年までの仕事を引継ぎ､細菌のエコ･コレクションの構築とそ
の意味付けに､取り組んだ｡このエコ･コレクションは､各対象1二壕に住む細菌群集を､平板上での
コロニーの形成に要した時間をH安に､増殖速度グループに頬別し､各グループから､それぞれ無作
為に選び､単離した細菌株(各グループ;30-50株)よりなる｡現在､二つの草地_l二項コレクション
とひとつの水Hコレクションを整備しつつある｡昨年､岩手人若尾氏らと行なった水凹コレクション
の各菌株のG+C含量比のデータを解析した結果､ (i)コレクション所属菌株全体についての､本含量
比の分布は､ 50%モル比を境に､低含量比グループと高含量比グループとに分かれる､ (ii)人半の菌株
は､後者のグループに属する､ ‖後者の分布のピークは､ 68%付近であることなどが､判明した｡こ
の結果は､ Harrisら(1994)が米国の複数の耕地土壌から直接抽出した各DNAのG+C含量比の分
布と､ほぼ一一致している｡ Harrisらの試料には､培養困難な細菌のDNAも含まれている｡両者の- ･
致は､エコ･エココレクションは､十の細菌群集の構成を相当程度よく反映していることを､意味し
ているといえる｡
(2)草地t壌コレクション所属各菌株のhopanoids化合物含有量を測定し､どの速度グループでも､70%
以卜の菌株にこれらの化合物が多量(人部分で数mg/g-drycell以上)に兄いだされた｡これらの化
合物は､細胞膜を補強する機能があるとされ､酸性の草地土壌条件､または_l二項 一般にかかわる条件
下で/冒舌する細菌群集の特徴と思われる｡現在､この点を解明中である｡
(3)水【tはよび草地コレクション所属の低栄養細菌の系統分類的類別のため､ 16SrRNAの塩基配列の-汰
定とこれらの細菌の形態的､生理的性質､細胞の微細構造の検討を行なっている｡また､各南棟のキ
ノン種の分析も開始した｡
(4)1二壌細菌の遺伝生態的研究を本格的に進める長期的目標として､土壌中における細菌の生理状態の
解明を取り上げることにした｡上壌中の細菌の大部分は､非増殖状態であるが､この状態を培養にお
ける定常期細胞の生理状態によって近似し､定常期細胞内における遺伝子発現とその制御機構の解明
を開始した｡すなわち､最初のモデル細菌として､遺伝子構造とその発現機構がもっともよく研究さ
れた人腸菌を選び､定常期細胞に特徴的な遺伝子発現に関連するRNAポリメラーゼのoBBLXJ子の遺伝
子rpoSの発現調節機構の解明を行なっている｡ (服部 勉､三井久幸､ E.アデル､李亨珍､斎藤明
宏)
-15 -農薬分解菌の解析‥異なった濃度で農薬分解を営む卜壌細菌の解析を行なっている｡これまでの結果
は､農薬分解菌は､高濃度条件と低濃度条件とで､異なっている可能性を示唆している｡ (佐藤 匡)
L壌炭化物の定立法‥ニュージランドの土地保全研究所で､卜壌炭化物の測定法開発をめざして､垂
クロム酸酸化にたいする抵抗性の研究を行っている｡ (佐藤 孜)
1994年1月-1994年12月に印刷発行された本研究センター職員の論文,
著書の抄録
Adel E. and T. Hattori : Comparative study of bacterial populations in agrassland soil in 1987
and 1992. Bull. Jap. Soc. Microb. Ecol. 9(2) : 67173, 1994.
Bacterial populations in a grassland s(一il (sampled in 1992) was studied in terms ()f
component colony-forming cuⅣes (cCFCs) t('be c('mpared with that in soil sampled in 1987･ The
simulated colony-forming curve (CFC) pattern was essentially similar to that (,f Hhe former
study ; that is, four cCFCs were Observed during 163h of incubation time･ Bacterial lS(〉lates were
picked up from colonies appearing along each cCFCs and clustered acc()rding to their morphological and physi()logical characteristics (biotypes)･ The histograms of the frequency
distribution of ir value for the isolates correspounding to CCFC gr()ups 1 , II and Ill showed a similar pattern as previously･ The trend of appearing of oligotrophic bacteria among the isolates ｡f cCFCs groups was also similar to that ()f the f()rmer study although the percent of ｡ligntr｡phic
bacteria differed ; that is, Oligotrophic basteria were not found among isolates (,f cCFCs groups
l and II , appeared at 30(yo in CCFC group Ill and increased to 68(ガ, in CCFC tfrOup Ⅳ ; aS theoligotr()phic bacteria increased, the sensitivity to 1 % Nacl also increased･ 1､he bacterial
populationof the grassland soil is considered to be comprised of at least four component groups
(CcFC groups) thr('ugh yearly variations, althoughthe biotype composition of the respective
groups varies either widely or narrowly.
Mochizuki, M. and T. Hattori : Effect of culture age on the kinetics of microcolony formation
using a soil oligotrophic bacterium. J. Gen. Appl. Microbiol･, 40 : 297-SOB, 1994･
The microcolony formation of a soll olig('tr｡phic bacterium, S2336, isolated from a paddy soil was observed by using microculture chamber and phase-contrast optlCSI The kinetics
｡f the microcolony formation was fnrmulated by the f()ll()wing m←)del : The micr()C()I()ny number N,attlme tisgivenby; N- N∞[ 1 - exp巨人( i- tr)H whereN∞ istheexpectednumber
of micr()colonies when time g('es to infinity,入is the rate ()f microc('l()ny appearance per unit time,
and tr is the retardation time. The model was, in form, the same as that of a first order chemical
reaction and thus called the first order reaction (FOR) m()del. In the previous studies using
Agroml)nas sp･ and Eshceri(/･hia ")li･ the tr values of the formation ofmicrocolonies were the same
whatever the culture agH)f parent cells was･ ln the present study'however, we ()bserved another
case in which the fr values ()∫ the bacterium, S2336, increased with the culture age of inoculum although the generation time was almost the same regardless of the age nf the inoculum･
ー16 -Sigalevich, P. A. T. Hattori and D, Ⅰ. Nikitin : Effect of UV-irradiation on the species diverslty
of culturable heterotrophic bacteria from paddy field soil. Bull. 丁ap. Soc. Microb. Ecol. 9(1) : 1-6,
1994.
The effect of moderate UV-irradiation (45 J /m2 ) on species diversity of aspor(噌enic
heterotrophic bacterial isolates from paddy fiels soil was studied. Although the isolates from
irradiated Petri dishes had less pr()n()unced hydr()1ytlC abilities and eutr()phs were less numerous,
irradiation d()d n()t result in specific selecti()n ()f UV-resistant bacteria. Species diversity indices were higher f()r the set of isolates from irradiated dishes･ This can be due to the fact that the
number of cells in()culated onto irradiated dishes was about one hundred higher than onto contr()1 dishes ; there may be a greaterchance for soil bacteria of minorgroups to form isolated c()I()れies on Irradiated dishes.
Shingaki, R" K. Gorlach., T. Hattori, K. Samukawa and H. Morisaki : Analysts Ofthe cell surface
charge of fast- and slow-growing bacteria isolated from a paddy soil. J. Gen. Appl. Microbiol"
40 : 469-475, 1994.
1n this study, thecell surface charge of 109 strains of the bacteria isolated from a paddy
s()il, whlCh showed a wide range of growth rates (0.7-15.1h in doubling time), were examined･ As
found in the case ()f grassland-soil bacteria previously (Morisaki etal. 8), among the strains,
fast-gr()wlng lSOlates showed a greater level of negative charge at the cell surface at pH71'o
compared with the slow-growing isolates. To determine the pH-dependence, the cell surface
charge was measured as a functlOn Of pH varylng from 2.4 to 9.(). Under acidic conditions, the
negative cell-surface charge became lower. At the most acidic conditi()n (pH 2.4) almost all of the
fast一growing isolates showed positive surface charge. This change in the cell surface charge
caused by pH-shift fr()m neutral to acidic c()nditi()n, which was considered to be due to that
charged functl()nal gr()ups (weak acid such as carboxylic acid) existing or exposed at the cell surface lost their negative charge, was greater for the fast一growing isolates than that f()r the sl｡W-growing ()nes.
The similar observations between the growth rate and the cell surface charge and the
pH-dependence of the cell surface charge, for three different type ()f soil bacteria, paddy soil
bacteria (this work), grassland soil bacteria (Morisaki et al.8) and Rhizt)bium sp. (Marshall 7), may
rerlect a general feature ()∫ the cell surface for s()il bacteria.
Gorlach, K., R. Shingaki, H. Morisaki and T. Hattori : Constructi()n of eco-collection of paddy
field soil bacteria for population analysis. ∫. Gen. Appl. Microbio1., 40 : 509-517, 1994･
When bacteria of a paddy field soil were incubated on counting plates the number ()f
colonies increased intermlttently with broadening inteⅣals. To analyze the bacteria populations,
30 to 51 bacteria were respectively isolated from the colonies appearing in each of the incubation periods : from 22 to 3Oh,二il to 51h, 52 to l14h, and 115 to 265h. The isolates from each period were
divided intogroups I , II , lIl , and Ⅳ.Thegeneration time()f bacteriaofeachgroup,grown on the liquid medium ()∫ the same composition as used for counting, increased in order from group l to group Ⅳ. Frequency distribution of generation time in each group was of Ltype･
M｡rphological and physiologlCal characteristics of the isolates differed among the types･ The
percentage of oligotrophic bacteria among isolates increased sharply fr()m group i t() group Ⅳ ･
Yamamoto ll･, K･ Sato, A. Katayama" S. Kuwatsuka, I. Watanabe, K. Inubushi and K. Senoo :
Recommended tests for assessing the side effects of pesticides on soil ecosystem.
Pesticides / Environment : Moleculae Biological Approaches (ed. by T. Mitsui, F. Matsumura
and I･ Yamaguchi), Pesticide Sci. Soc. of Japan, Tokyo pp. 333-344, 1994.
Some ()f possible tests were proposed for environmental assessment ()i the
pesticide-application to agriculturaHield based on the results obtained by the studies conducted
by the authors_ The main contents of this paper were as follows :
lntroduction. Which processes and organisms are of major importance?
Recommended laboratory tests :
Test conditions, 1. Selection of soils, 2. Soil storage, preparation and pre-incubati()∩, 3. Pesticide treatment, 4. Test peri()d,
Test under upland field conditions, 1. Mineralization of organic matters, 2. Nitrification, 3. Microbial biomass,
Test under paddy field c()nditi()ns, 1. Air-drying effect on ammonification, 2. Mineralization of
organic matters, 3･ Nitrification, 4･ Ⅰ)enitrification, 5･ Algal growth, 6･ Nonsymbiotic
nltrOgen-fixation, 7. Micr()blal biomass,
Signlficance of microbial counts
Methods ofmicrobialcounts,
Interpretation and evaluation ()f data,
Concrusjons
K･ Sato: Chapter 4 Effect of nutrients on interaction between pesticide pentachlorophenol and
microorganisms in Soil. Bioremediation through Rhizosphere Technology (ed. by Anderson
T. and ∫. R. Coats)
American Chemical Soc, Washington, DC pp.43-55, 1994.
An investlgation was conducted ()n the interatinn between the pesticide PCP
(pentachlorophenol) and bacteria in soil supplemented with amin() acids and carbnhydeates in light of the fact that nutrient concentrations for microorganisms are greater in rhizosphere
soil than in nonィhizosphere soil. PCP did not markedly delay the start of degradati()n ()i the
amino acids and glucose, and the numbers of bacteria also increased in connection with the
degradation･ Bacterial flora established by PCP application were modified by the addition of
amino acids. Degradation ()f PCP, and the increase in the number of PCI'-degrader(S) Were
delayed in the presence of amino acids and glucose, but not in the presence ofcellulose. These
results suggest that, in general, the interaction between pesticides and micrnorganisms in rhizosphere soil is different than in non-rhizosphere soil.
Lee Sang-Bok., K. Sato and Jae-Don∴ Influence of repeated application of chlorothatonil and
cellulose on the bacterial populations in soil suspension culture. Korean Soc. Soil S°i. Fertil.
27(1) : 48-53, 1994 (Korean with English Summary)
This study was c()nducted t() find out the influence of single and ′′′ or repeatedly combined application of ceHulose and chlorotharonil (TPN) on bacterial population and
dissipation of these chemicals by microorganism in the soil suspension culture.
1･ The number of total bacteria and Gram-negative bacteria were rapidly increased for lst
week, afterthe time, decreased in the single application but maintained in repeatedly c()mbined
applicati｡n for 5th week and that were higher at combined application ｡f TPN and cellulose
than at slngle application ｡f these.
一18 -2. TPN-degrading bacteria were gradually increased by the repeated application of TPN, and
elevated the increaslng extents Of those with the repeatedly combined application of cellulosewith
TPN.
3. Cellulose-degrading bacteria showed the peak at lst week, and was increased in the repeated
application of cellulose, but the bacteria was decreased in the repeatedly application of TPN with
cellulose.
4. The dissipation of TPN were faster at the combined application of both than at the single application of TPN, wheras that was delayed by the repeatedly combined application.
5. The content of reducing suger was rapidly increased at lst week and after 4 th week except for the TPN single application, thatwas higher in the combind application than the cellulose single,
but there was no difference between them.
Jiang, H-Y, and K. Sato: DNA base composition of bacterial groups differentiated by a diagnostic
scheme used for soil isolates. Soil S°i. Plant Nutr. 40 : 675-681, 1994.
In order to confirm the relations between the phenotypIC Characteristics and genetic character the bacterial isolates from the root surface of wheat grown under different soil
c()nditions were investigated. A total 161 Gram-negative and 108 Gram-positive bacterial strains
were ass()rted int() respective 8 and 4 groups using the conventional phenotyplC Criteria.
Guanine-Cytosine % of DNA of all the bacterial strains of the respective groups was determined. Although most of the groups were justified by the genetic criterion, a few group such like Flauobacterla and CyioPhaga group and coryne-from bacterial group was not assorted as a
homogeneous group from the genetic criterion.
Jiang, H-Y, and K. Sato: Interrelationships between bacterial population on the root surface of
wheat and growth of plant. Soil S°i. Plant Nutr. 40 : 683-689, 1994.
The relationships between populations of several bacterial groups on the root surface of wheat and the growth of wheat were studied. A linear correlation was found between populations and growth of plant for phosphate-solubilizlng bacteria, FPP-Pseud(Jm(masspp., and decomposing bacteria. The numbers of phosphate-S｡1ubilizing and
cellulose-dec｡mpsing bacteria on the r()ot surface tend t() be higher when the gr()wth of wheat increased,
while the numbers of FPP-PLb･eud()mt)nag spp., decreased following the increase in the growth of
plant. However, no slgnificant correlations were obtained for total bacterial counts and NH4
-Oxidizing bacterial group.
Mitsui, H" K Nakatani, K. Yamaguchi-Shinozaki, K. Shinozaki, K. Nishikawa and H.
Takahashi: Sequenching and characterization of the kinesin-related genes kaiB and katC of
Arabidopsis thaliana. Plant Mol. Biol. 25 : 8651876, 1994.
Complementary DNAs of two kinesin-related genes, kaiBand kale were isolated from
ArabidoPsis thallanaand and sequenced. The carboxyl-terminal regions of the polypeptides encoded by these genes, especially the presumptive ATP-binding and micr()tubule-binding
domains, share significant sequence homology with the mechanochemical motor domai｡n of the
kinesin heavy chain. The predicted secondary structures of KatB andKatC proteins include a
large globular domain in the carboxyトterminal region and a small globular domain in the amino-terminal region that are separated by a long α -helical coiled-coil with heptad repeats. A
truncated KatC polypeptide (KatC (207-754)), which includes the carboxyl-terminal region of KatC , was expressed in Escherichia colt and was shown to possess microtubule-stimulated ATPase activity and to bind to microtubules in an ATP-sensitive manner, both of which are
19 -characteristics ()f kinesin and kinesin-like proteins.
Hattori, T": Soil microenvironment. Soil Protozoa, ed. by J. E. Darbyshire, CAB International,
0Xon, U. K. pp. 43-64, 1994.
Introduction
I)evelopment of the concept of the/Soil microenvironment Microfloral distribution within soil aggregates
Microscopical ()bservations of s()il aggregates
Distribution and behaviuor of prot()zoa within ahd am()ngst s()il aggregates Future invetstlgati()ns ()f the soil microenvir｡nment
ln this chapter, the devel()pmentoftheconcept ofthesoil enviroment is dlSCuSSed briefly, roll()Wed by a more detailed treatment of the distribution of protozoa and other micr()nrganisms in this environment. As indivldual s()il aggregates are c()nvenient units ofs()il structurre, the dlStributi()∩ and behavlOur Of soil micr()organims in soil aggregates are emphasized. Finally, S()me aspects nf the s()il envir()nment that clearly need t() be investigated in the future are discussed.
学会での目頭発表,展示発表
Hattori, T.and M. Mochizuki: Kinetics of dividing of stationary phase-cells on a fresh
medium.Ocean Research lnstiture Symposium. (January 10 and ll. Tokyo.)
Adel,E. -B. and T.Hattori: H()panoids in grassland soil bacteria.口本1._壌肥料学会( 4日2 - 4
日､京都)
服部繁子､渡辺 階､外崎 昭､服部 勉:低栄養細菌S213の形態におよはす塩･イJ一機物の影響｡日
本土壌肥料学会(4月2-4日､京都)
芳賀英樹､若尾紀夫､服部 勉:ゲノムDNAのGC含量比とゲノムサイズからみた_l二壌細繭群｡日
本土壌肥料学会(4J12-4日､京都)
若尾紀夫､芳賀英樹､笠原康裕､服部 勉:ゲノムサイズからみた_卜壌細菌群の特性.｡日本微/I二物/l:.
態学会(12日16-18日､大阪)E:B.アデル､服部繁子､服部 勉:草地細菌群におけるホパノイドの分布｡ u本微!l二物生態学会(12
月16-18日､大阪) 服部葬√-､渡辺 暗､外崎 昭､服部 勉:低栄養細菌の細胞構造｡日本徴/1物生態学会(12j116-18日､大阪)析垣隆資､寒川喜三郎､森崎久雄､服部 勉:水田土壌より単離した細菌の細胞表面特性｡日本徴/1･:
物/II態学会(12月16-18日､人阪)小関 茶､佐藤和犬､佐藤 匡､一条邦夫:水H L壌および水稲の/I:_再に及ぼす融雪剤の影響に関す
る調査｡
1.土壌の化学的性質について｡日本土壌肥料学会(1994. 4.京都)
佐藤利夫､小関 茶､一条邦夫､佐藤 匡:水田上壌および水稲の年育に及ぼす融雪剤の影響に関す
る調査｡
2. _l二壌の窒素の変化と水稲の生育について｡口本卜壌肥料学会(1994. 4.京都)
Sato, K. and H-Y. Jiang, : Bacterial flora on the root surface of wheat grown under different
soil conditions, International Congress of Myclolgy and Bacteriology, IUMS '94 (7. 3-8, Praha,
Czech).
臨界生態遺伝研究部門
当研究部門では､ ^｣二的に創り出した紫外線や二酸化炭素濃度の増大などの複合環境安内の変動が植
物や徴牲物の年商､生態に及ぼす影響を実験生態学的に解析し､ LtI態系における種の動態や生物生産
の動向のT･測に資すると同時に､臨界環境に耐性をもつ遺伝資源の探索に寄与する基礎研究を行って
いる｡紫外線など複合環境要因の変動がイネの牲青に及ぼす影響の生理学的､遺伝学的解析:我々はこれま
で､ Inl LlI-:態型や品種群に属する品種でも紫外線に対して異なった感受性を示し､紫外線量の多い南
方地域の栽培イネが必ずしも強い抵抗性を示さず､ u本型水稲､ boro刊イネに強い抵抗性を示す品種
が多く含まれていること､ U本当-.!水稲グループのうちササニシキは強い紫外線抵抗性を示すが農林1
号は弱い抵抗性を示すことを見Jl=ノ､生理学的､遺伝学的解析を行ってきた( Physiol. Plant., 91, 234,
1994)｡ところで､これらはUV-Cを約10%含むUV-Bを川いて得られてきた成果である｡本年度
は純粋なUV-B環境を作r)だし､ UV-Bがイネの/1:.再に及ぼす影響を調べた｡
(1)UV-Bはイネのバイオマス､分げっなどの生育､葉身窒素含量､ Rubisco含量などを抑制するこ
と､品種間差異は厳しい条件になると顕在化すること､エネルギー効果は低いがUV-Bの生物効果
は基本的にはUV-Cと異なった機能を持たないこと､ UV-Bは蛋白合成､窒素の取込みに影響し､
この面での差異がキーの一つであることを示した｡ (2)蘭農度C02は純粋なUV-Bの生物効果を打
ち消す｡ここでも品種間差異が認められた｡ (3)UV -Bによって誘導されるフラボノイドなど紫外
側又物質の蓄積の仕方において占占椎間差異が認められた(1994､植物学会で発表)｡ (4)ブルックへ7､
ン研究所のSutherland夫妻と共同研究を行い､ DNAピ1)ミジンダイマ-の作成と光修復速度で品種
間にも差異を見出した｡今年度も共同研究の継続を計画している｡ 2つの同際会議"Climate Change
and Rice" , "Plant Responses to Environmental Stress"にて招待講演を行った｡
