R e la tive expr es si on
A
B
R e la tive expr es si on
a
b bc
bc bc
c d
a
b bc
bc bc bc
c
Figure 15. Transcription of AtMATE and ALS3 in Arabidopsis roots in response to various treatments.
Transcript levels of Al-responsive genes (AtMATE; A and ALS3; B) were determined by real-time PCR in wild-type (Col-0) seedling roots after 6 h treatments with IAA (10ȝ0), ABA (100 ȝ0), H2O2(300 ȝ0), AlCl3(10 ȝ0), flg22 (10 ȝ0), or low pH (pH 4.7). Transcript levels were normalized to that of UBQ1, and relative expressions (treatment/control) were calculated. Values are mean 㼼SD (n = 3). Different letters indicate significant difference from transcript level in control (P< 0.05, Tukey’s test).
⪃ᐹ
ᮏ❶࡛ࡣ, ࢩࢢࢼࣝㄏᑟᅉᏊࡉࢀࡿᗄࡘࡢ᳜≀࣍ࣝࣔࣥ, Ꮫ≀㉁ࡀ▷ᮇ (6 㛫௨ ෆ)࡛ࡢAtALMT1Ⓨ⌧ࢆㄏᑟࡋࡓ. ᳜≀࣍ࣝࣔࣥ (IAAABA), H2O2, పpHཬࡧflg22 ࡀ᭷ពAtALMT1㌿㔞ࢆቑຍࡉࡏࡓ(Figs. 9 and 13). ࡇࢀࡣ, AtALMT1ࡀ」ᩘࡢࢫࢺ
ࣞࢫᛂ⟅ࡋ, ࠸ࡎࢀࡢࢩࢢࢼࣝㄏᑟᅉᏊࡀ⏕ࡌࡿࡇࢆ♧ࡋ࡚࠸ࡿ. IAA ཬࡧABAࢩ ࢢࢼࣝኚ␗య࡛࠶ࡿnph4-1arf19-1ཬࡧabi1-1ࢆ⏝࠸ࡓゎᯒࡼࡾ, IAA, ABAᛂ⟅ࡋࡓ
AtALMT1 Ⓨ⌧ࡀ, ࡑࢀࡽࡢཎᅉ㑇ఏᏊࡢ㛵㐃ࡍࡿ⤒㊰ࡼࡗ࡚௰ࡉࢀ࡚࠸ࡿࡇࢆ᫂
ࡽࡋࡓ (Fig. 10). nph4-1arf19-1 ࡣ, ARF-Aux/IAA ࢱࣥࣃࢡ㉁ SCFTIR1/AFB ࡢ
ARF-Aux/IAAࢱࣥࣃࢡ㉁ศゎࡼࡗ࡚ไᚚࡉࢀࡓ IAA ࢩࢢࢼࣝఏ㐩⤒㊰ࡀ㐽᩿ࡉࢀ࡚࠸
ࡿ (Quint and Gray, 2006). ྠᵝ, abi1-1 ࡘ࠸࡚ࡣ, PP2C/SnRK2 ࢆࡋࡓṇᖖ࡞
ABAࢩࢢࢼࣝఏ㐩ࡀ⾜ࢃࢀ࡞࠸ (Umezawa et al., 2009). ࡇࢀࡽࡢIAAཬࡧABAࢩࢢࢼ
ࣝఏ㐩ࡀ, Al ࡼࡿ▷ᮇ࡛ࡢAtALMT1ࡢ㌿άᛶ┤᥋ⓗ㛵ࡍࡿ࠺ࡣࡉࡽ
࡞ࡿゎᯒࢆᚲせࡍࡿࡀ, ࡇࢀࡽࡢኚ␗య࡛ࡣ, Alฎ⌮ࡼࡿAtALMT1ࡢㄏᑟࡣ㔝⏕ᰴ࡛
ࡢㄏᑟྠ⛬ᗘ࡛࠶ࡿࡇࡀ♧ࡉࢀࡓ (Fig. 10). ࡲࡓ, Al ฎ⌮ࡉࢀࡓ㔝⏕ᰴ࡛, ᪤▱ࡢ IAAཬࡧABAᛂ⟅㑇ఏᏊࡢㄏᑟࡣㄆࡵࡽࢀ࡞ࡗࡓ (Fig. 11). ᚑࡗ࡚, AtALMT1Ⓨ⌧ࡢ Alㄏᑟࡣ, ༢ࡇࢀࡽ࣍ࣝࣔࣥࡢ1ࡘࡼࡗ࡚ไᚚࡉࢀ࡚࠸ࡿࢃࡅ࡛ࡣ࡞࠸⪃࠼ࡽࢀࡿ.
ࡲࡓ, IAAཬࡧABAࢩࢢࢼࣝఏ㐩ࡣ, flg22ࡼࡿ▷ᮇ࡛ࡢAtALMT1Ⓨ⌧┤᥋ⓗ㛵
ࡋ࡚࠸࡞ࡗࡓ (Fig. 13). SAཬࡧMeJAࡣ, ⏕≀ⓗࢫࢺࣞࢫᛂ⟅࠾࠸࡚㘽࡞ࡿࢩࢢ ࢼࣝᅉᏊࡉࢀࡿࡀ, AtALMT1 Ⓨ⌧ࡢㄏᑟࡣㄆࡵࡽࢀ࡞ࡗࡓ (Fig. 9). ࡇࡢࡇࡣ,
flg22ࡼࡿⓎ⌧ㄏᑟࡑࢀࡽࡢࢩࢢࢼࣝᅉᏊࢆࡍࡿࢩࢢࢼࣝఏ㐩ࡀ┤᥋ⓗ㛵ࡋ࡚࠸
࡞࠸ࡇࢆ♧၀ࡍࡿ. ୍᪉࡛, H2O2ࡲࡓࡣపpH࡛ࡢࢩࢢࢼࣝࡀ, Alཬࡧflg22ࡼࡿㄏᑟ ᶵᵓྵࡲࢀࡿྍ⬟ᛶࢆṧࡋ࡚࠸ࡿ. ࢩࣟࢾࢼࢬࢼ࡛ࡢ᳜≀ཎ⳦ឤᰁ (Pst DC3000)
ᑐࡍࡿ㑇ఏᏊⓎ⌧ᛂ⟅ࡀ, పpHᑐࡍࡿᛂ⟅㢮ఝࡋ࡚࠸ࡿࡇࡀࡑࢀࡒࢀࡢࢺࣛࣥࢫࢡ
ࣜࣉࢺ࣮࣒ࡢẚ㍑ゎᯒ࡛♧ࡉࢀࡓ (Lager et al., 2010). ࡲࡓ, flg22ࢆྵࡴᚤ⏕≀㛵㐃ศᏊ
ࣃࢱ࣮ࣥࡢㄆ㆑ඹᙺࡋ࡚ H2O2⏕ᡂࡀ⏕ࡌࡿࡇࡀ▱ࡽࢀ࡚࠸ࡿ (Torres et al., 2006).
H2O2పpHฎ⌮ࡣAtALMT1Ⓨ⌧ࢆㄏᑟࡍࡿࡇࢆ♧ࡋࡓࡀ, Alฎ⌮ࡣ᰿➃࡛H2O2ࢆ 㞟✚ࡋ (Kobayashi et al., 2005), ⣽⬊ෆpHࡢపୗࡘ࠸࡚ࡶ☜ㄆࡉࢀ࡚࠸ࡿ (Moseyko and Feldman, 2001). ࡇࢀࡽࢆ㋃ࡲ࠼, ᚋ, Alཬࡧflg22࡛ࡢAtALMT1ᛂ⟅㛵ࢃࡿᅉ Ꮚࡢ㛵ಀᛶࢆ᫂ࡽࡍࡿᚲせࡀ࠶ࡿ.
ゎᯒ⏝࠸ࡓIAA, ABAࢩࢢࢼࣝኚ␗ᰴࡣ, Al᰿㛗㜼ᐖ࠾࠸࡚ឤཷᛶࢆ♧ࡉ࡞ࡗࡓࡅ
ࢀࡶ, IAAཬࡧABAࡀ㛵ࡍࡿᛂ⟅ࡣ, Al⪏ᛶ㈉⊩ࡍࡿࡶࡋࢀ࡞࠸. ᰿ࡢ᰿㛗㜼ᐖ ࡣ, Alẘᛶࡼࡾ㢧ⴭ⾲ࢃࢀࡿ㞀ᐖ࡛࠶ࡿ. ⮬↛⏺࠾࠸࡚, ᰿ࡢᵓ㐀ࡣ, Ỉࡢ⋓ᚓࡸ
⇱⪏ᛶᙳ㡪ࡍࡿ (Xiong et al., 2006). ഃ᰿ᙧᡂࡢ㛤ጞࡣIAA㞟✚ࡼࡗ࡚ไᚚࡉࢀ࡚࠾
ࡾ, nph4-1arf19-1 ࡛ ࡣഃ ᰿ ᙧ ᡂ ࡀ ᦆ ࡞ ࢃ ࢀ ࡚࠸ ࡿ (Okushima et al., 2007). ࡲ ࡓ, AtALMT1promoter::GFPࢥࣥࢫࢺࣛࢡࢺࢆᑟධࡋࡓᙧ㉁㌿య࡛ࡣ, ࢩࢢࢼࣝᅉᏊࢆฎ⌮
ࡋ࡚࠸࡞࠸᮲௳࡛,ഃ᰿ᙧᡂ㒊࡛ࡢGFP⺯ගࡀほᐹࡉࢀࡓ (Fig. 16). IAAࡼࡿㄏᑟ㛵 㐃ࡍࡿ㒊ࡣ, Al᥋ࡍࡿࡼࡾ๓AtALMT1ࡀᒁᅾ࡛ࡁࡿ⪃࠼ࡽࢀࡿ. ୍᪉, ⇱
ࡉࢀࡓ᰿㒊ࡣ, 㛗㊥㞳ࢩࢢࢼࣝࢆࡋ࡚ẼᏍ㛢㙐ࢆ㛤ጞࡍࡿ ABA ࢆྜᡂࡋ, ⇱⪏ᛶࢆ⋓
ᚓࡋ࡚࠸ࡿ (Zhang et al., 2006). ABAฎ⌮ࡼࡾAtALMT1ࡀㄏᑟࡉࢀࡿࡇࢆ♧ࡋࡓࡀ, ࡇࡢᛂ⟅ࡣ⇱ࢫࢺࣞࢫୗ࠾࠸࡚, ᰿ࡢⓎ㐩㜼ᐖࡼࡾ⇱ឤཷᛶࢆࡉࡽᝏࡍࡿࡇ
࡞ࡿAlẘᛶࡽ᰿ࢆಖㆤࡍࡿࡇ㐺ࡍࡿࡶࡋࢀ࡞࠸. Alฎ⌮࡛ࡢABA㞟✚ࡣ࢜࢜
࣒ࢠࡸࢲࢬ࡛ሗ࿌ࡉࢀ࡚࠸ࡿ (Kasai et al., 1993; Hou et al., 2010). ᚑࡗ࡚, IAAཬࡧ ABA㛵㐃ࡍࡿᛂ⟅ࡀ⮬↛⏺࠾࠸࡚ࢩࣟࢾࢼࢬࢼࡢAl⪏ᛶ㈉⊩ࡍࡿࡶࡋࢀ࡞࠸.
Lakshmananࡽ (2012)ࡣ, ࢩࣟࢾࢼࢬࢼᆅୖ㒊ࡢflg22ฎ⌮ࡼࡗ࡚, ABA㞟✚
ẼᏍ㛢㙐㝶ࡋ࡚᰿㒊࡛ࡢAtALMT1ࡀㄏᑟࡉࢀࡿࡇࢆሗ࿌ࡋࡓ. ABAࢩࢢࢼࣝఏ㐩
ࢆࡋࡓ AtALMT1 Ⓨ⌧ࡣ, 㛗㊥㞳ࢩࢢࢼࣝࢆࡍࡿ⏕≀ⓗࢫࢺࣞࢫ⪏ᛶᶵ⬟ࡍࡿࡇ
ࡀ♧၀ࡉࢀࡿ. ୍᪉࡛, ᰿㒊ࡢ┤᥋ⓗ࡞flg22ࡀฎ⌮ᚋ6㛫࡛AtALMT1ࢆㄏᑟࡋࡓ
GFP DIC Merge
Figure 16. Histochemical analysis of AtALMT1 expression during lateral root formation in Arabidopsis. Transgenic Col-0 harboringAtALMT1promoter::GFP (GFP reporter fused with -1738 from the first ATG) was grown for 10 days in control solution (pH 5.5). Expression of GFP at lateral root initiation site was observed by an LSM 710 laser scanning microscope (Zeiss, Tokyo, Japan) with excitation at 488 nm (Argon laser) and emission at 490 to 540 nm to detect GFP.
Images were processed using ZEN 2009 software (Zeiss).
(Fig. 13). ࡇࡢᛂ⟅ࡣ, Bacillus subtilis strain FB17ࡢࡼ࠺࡞᭷⏝᰿ᅪ⣽⳦ࢆຠ⋡ⓗ㞟✚
࡛ࡁࡿ⪃࠼ࡽࢀࡿ. FB17 ࡣ, ࣜࣥࢦ㓟㉮ᛶࢆ᭷ࡋ࡚࠾ࡾ, ᰿ࡢ⾲㠃㞟✚ࡉࢀࡿ᳜
≀ཎ⳦ឤᰁࡢ㌟ㄏᑟᢠᛶࢆㄏᑟࡋ, AtALMT1ࢆࡋࡓࣜࣥࢦ㓟ᨺฟࡣFB17ࡢ㞟
✚ᚲせ࡛࠶ࡿ(Rudrappa et al., 2008). ࣮࢜ࢺࢡ࣮ࣞࣈࡋࡓFB17ᇵ㣴ᾮࢆ⏝࠸ࡓFB17
⏤᮶ࡍࡿ࢚ࣜࢩࢱ࣮ฎ⌮࡛ࡣAtALMT1ࡢㄏᑟࡣㄆࡵࡽࢀ࡞ࡗࡓࡀ (Lakshmanan et al., 2012), ࡇࢀࡣ, 㠴ẟ࠾ࡅࡿflg22࣌ࣉࢳࢻࡢಖᏑ㓄ิࡀ␗࡞ࡿࡇࡀ⪃࠼ࡽࢀࡿ. ᰿ ᅪᏑᅾࡍࡿflg22࣌ࣉࢳࢻ㓄ิࢆಖᣢࡍࡿูࡢ⣽⳦✀ࡀ, AtALMT1౫Ꮡࡍࡿࣜࣥࢦ㓟 ᨺฟࢆᙉࡍࡿࡇࡼࡾ᭷⏝⳦ࡢ㞟✚ࢆቑຍࡉࡏࡿࡇࡀணࡉࢀࡿ.
ࣉ࣮ࣟࣔࢱ࣮ゎᯒࡣ, ྛ✀ࡢࢩࢢࢼࣝᅉᏊᑐࡍࡿ」㞧࡞ AtALMT1 Ⓨ⌧ᶵᵓࡢ୍㒊ࢆ
᫂ࡽࡋࡓ. ABAᛂ⟅㓄ิࡀ, 㛤ጞࢥࢻࣥࡼࡾୖὶ-317 bpࡽ-1110 bpࡢ㡿ᇦಖᣢࡉ
ࢀ࡚࠸ࡿࡢᑐࡋ࡚, ࡢࢩࢢࢼࣝᅉᏊࡢᛂ⟅㓄ิࡣ-292 bpࡽ-317 bpᏑᅾࡍࡿࡇ
ࡀ♧ࡉࢀࡓ (Fig. 12). PLACEཬࡧPlantCAREࡼࡾ, ࣉ࣮ࣟࣔࢱ࣮㡿ᇦ (ATGࡼࡾୖὶ -1110 bp)⇱ᛂ⟅ࢩࢫไᚚ㓄ิࡀ᳨ฟࡉࢀࡓ (Table 8). ࡲࡓ, -292 bpࡽ-317 bpࡢ㡿 ᇦࡣ, ࢿ࡛ྠᐃࡉࢀ࡚࠸ࡿ ART1 ࡢ⤖ྜࡍࡿࢩࢫ㓄ิ GGN(T/g/a/C)V(C/A/g)S(C/G) (Tsutsui et al., 2011)ࡀྵࡲࢀ࡚࠸ࡓ. AtALMT1 Ⓨ⌧ࡣ ART1 㧗࠸┦ྠᛶࢆ♧ࡍ STOP1ࡀᚲ㡲࡛࠶ࡿ (Iuchi et al., 2007). STOP1ࡢࡇࡢࢩࢫ㓄ิࡢ⤖ྜࡀAtALMT1Ⓨ
⌧ไᚚ㔜せ࡛࠶ࡿྍ⬟ᛶࡀ㧗࠸. ྠᵝ STOP1 ࡼࡗ࡚ไᚚࡉࢀࡿ AtMATE ࡀ, AtALMT1ࢆㄏᑟࡋࡓࢩࢢࢼࣝᅉᏊᛂ⟅ࡋ࡚࠾ࡾ, ᗄࡘࡢSTOP1ࡼࡾไᚚࡉࢀࡿ㑇 ఏᏊࡣ」ᩘࡢࢫࢺࣞࢫࡢᛂ⟅ࢆྍ⬟ࡍࡿไᚚᶵᵓࢆඹ᭷ࡋ࡚࠸ࡿࡇࡀ⪃࠼ࡽࢀࡿ.
⤖ㄽࡋ࡚, ᮏ❶࡛ࡣ, 」ᩘࡢࢩࢢࢼࣝᅉᏊᑐࡍࡿAtALMT1ࡢ」ྜⓗ࡞㌿ᛂ⟅ࢆ♧
ࡋ࡚࠸ࡿ. ࡋࡋ࡞ࡀࡽ, 㐺ษ࡞ࣜࣥࢦ㓟ᨺฟ࡛ࡣ, AtALMT1 ࢱࣥࣃࢡ㉁ࡀάᛶࡉࢀ࡞
ࡅࢀࡤ࡞ࡽ࡞࠸. ࢱࣥࣃࢡ㉁ࡢάᛶᶵᵓࡶ」㞧ไᚚࡉࢀ, ᰿ᅪࡢࣜࣥࢦ㓟ᨺฟไᚚ ࡢูࡢ㔜せ࡞せᅉ࡛࠶ࡿ. ࡇࢀࡲ࡛, AtALMT1ࡢࣜࣥ㓟·⬺ࣜࣥ㓟ࡀAlక࠺άᛶ
㛵㐃ࡍࡿࡇࡀ♧ࡉࢀ࡚࠸ࡿ (Kobayashi et al., 2007). ヲ⣽࡞㐣⛬ࡣྠᐃࡉࢀ࡚࠸࡞
࠸ࡅࢀࡶ, ᭷⏝᰿ᅪᚤ⏕≀ࡼࡿࣜࣥࢦ㓟ᨺฟࡢቑຍ (Rudrappa et al., 2008)ࡣ, 㢮ఝ ࡋࡓάᛶᶵᵓࢆᚲせࡍࡿࡇࡀணࡉࢀࡿ. ࢩࢢࢼࣝᅉᏊฎ⌮࡛, ABAH2O2ࡣฎ⌮
ᚋ24㛫࡛ࡢࣜࣥࢦ㓟ᨺฟࡀㄆࡵࡽࢀࡓ (Fig. 17). ᚑࡗ࡚, AtALMT1άᛶࡶᗄࡘ
ࡢࢩࢢࢼࣝᅉᏊࡀ㛵ࡍࡿࡶࡋࢀ࡞࠸. ᳜≀ࡀࢫࢺࣞࢫᛂ⟅ࡋ࡚ࡢࡼ࠺ࣜࣥࢦ㓟 ᨺฟࢆไᚚࡋ࡚࠸ࡿࢆ⌮ゎࡍࡿࡓࡵ AtALMT1 ࡢάᛶ㐣⛬ࢆྵࡵࡓࡉࡽ࡞ࡿ◊✲ࡀ ᚲせࡉࢀࡿ.
0.0 0.1 0.2 0.3 0.4 0.5
0.0 0.1 0.2 0.3 0.4 0.5
Malaterelease (nmol/plant /24h) Malaterelease (nmol/plant /24h)
A B
Figure 17. Malate release to various chemicals in Arabidopsis thaliana. The roots of aseptically grown Col-0 seedlings were incubated in basal solutions containing 10 ȝ0 AlCl3, 300 ȝ0H2O2, 10ȝ0IAA, 100ȝ0ABA and adjusted at pH 4.7 (Low pH) (A) and 10ȝ0flg22 (B) for 24 h. Means㼼SE values are shown (n= 3).
⥲ྜ⪃ᐹ
SGCS࡛ࡢ㟼㟁ⓗࣔࢹࣜࣥࢢࡣ, ᚑ᮶ࡢ᰿㛗㜼ᐖࡢࡼ࠺࡞⏕⌮ⓗ࡞ᛂ⟅ࡔࡅ࡛࡞ࡃ, 㑇ఏ ᏊⓎ⌧ゎᯒ࡛♧ࡉࢀࡓࡼ࠺⣽⬊ෆ࡛ࡢศᏊ࡛ࣞ࣋ࣝࡢᛂ⟅༑ศ㐺ྜࡋ, ࢩࣟࢾࢼ ࢬࢼ࡛ࡢ Al3+, H+ẘᛶཬࡧ Ca2+㍍ῶᶵᵓࡢ᳨ドᙺ❧ࡘࡇࢆ♧ࡋࡓ. ᵝࠎ࡞᳜≀✀࡛ࡢ
㏆ᖺࡢAl⪏ᛶ◊✲ࡣ, ࢩࣟࢾࢼࢬࢼ࡛ࡢSTOP1 (Iuchi et al., 2007), ࢿ࡛ࡢART1
(Yamaji et al., 2009)࡛௦⾲ࡉࢀࡿࡼ࠺, Ỵᐃⓗ࡞㌿ไᚚᅉᏊࢆࡋ࡚⪏ᛶ㑇ఏᏊࡢⓎ
⌧ࡀไᚚࡉࢀࡿࡇࢆሗ࿌ࡋ࡚࠸ࡿ. ᮏ◊✲࡛ࡢ⤖ᯝࡣ, Al⪏ᛶ㑇ఏᏊࡢⓎ⌧ᛂ⟅ࡘ࠸࡚, PM࡛ࡢAl3+ࡢཷᐜ ({Al3+}PM)ࡼࡗ࡚ㄏᑟࡀᘬࡁ㉳ࡇࡉࢀࡿࡇࢆ᪂ࡓࡅຍ࠼ࡿ.
㠀⏕≀, ⏕≀ⓗࢫࢺࣞࢫඹ, ࣞࢭࣉࢱ࣮ࢱࣥࣃࢡ㉁ࢆࡍࡿ㌿ไᚚࡢάᛶࡣࡑࢀ
ࡒࢀࡢ⪏ᛶ㔜せ࡞ᙺࢆᯝࡓࡋ࡚࠸ࡿ. Toll-likeࣇ࣑࣮ࣜࢱࣥࣃࢡ㉁ᒓࡍࡿFLS2ࡣ,
⣽⬊እࡢleucine-rich repeatࢻ࣓࡛ࣥflg22ࢆㄆ㆑ࡋ, ཎ⳦ᑐࡍࡿᢠᛶࢆ⋓ᚓࡍࡿ
ࡓࡵࡢᶵᵓࢆㄏᑟࡍࡿ (Gomez-Gomez and Boller, 2000). ࡲࡓ, cysteine-rich repeatࢻ࣓
ࣥࢆಖᣢࡍࡿreceptor-like cytosolic kinase (RLCK)ᒓࡍࡿARCK1ࡣ, Ⓨⱆᚋẁ㝵࡛
ᾐ㏱ᅽࢫࢺࣞࢫཬࡧABAࡢࢩࢢࢼࣝࢆไᚚࡍࡿ」ྜయࡢ୍㒊࡞ࡿࡇࡀሗ࿌ࡉࢀ࡚࠸ࡿ
(Tanaka et al., 2012). PM࡛ࡢ┤᥋ⓗ࡞Al3+ࡢ㟼㟁ⓗ┦స⏝ࢆ⾲ࢃࡍSGCSࣔࢹࣜࣥ
ࢢࡣ, ࣞࢭࣉࢱ࣮ࢱࣥࣃࢡ㉁ࡶࡋࡃࡣ PM ࡛ࡢ Al3+ࡽ⏕ࡌࡿ⣽⬊ෆ࡛ࡢࢩࢢࢼࣝ⤒㊰ࢆ
ྠᐃࡍࡿࡓࡵ, ᚋࡢゎᯒ࠾࠸࡚㔜せ࡞ࣔࢹࣝ࡞ࡿ⪃࠼ࡽࢀࡿ.
ࡇࢁ࡛, Al3+, H+ẘᛶࡢSGCS ࣔࢹࣜࣥࢢᇶ࡙ࡃ᳨ドࢆࡍࡿࡓࡵ, ẚ㍑ⓗ㧗࠸pH ࡢỈ⪔⁐ᾮࢆゎᯒ⏝࠸ࡓ. ᰿㛗㜼ᐖࡼࡾ, pH 5ࡽ5.5࡛ࡣ, {Ca2+}PMࡼࡿ㍍ῶࡀ㛵ಀ ࡍࡿ{Al3+}PM, {H+}PMẘᛶࡀᏑᅾࡍࡿࡇࢆ♧ࡋࡓ. 㓟ᛶᅵተࢫࢺࣞࢫᑐࡍࡿࣇ࣮ࣝࢻ
◊✲╔┠ࡍࡿ, ከࡃࡢᶞᮌཬࡧ∾ⲡࡣ, pH ࡀ4௨ୗࡢ㓟ᛶᅵተ࡛ࡶ༑ศ⏕⫱ࡍࡿࡇ
ࡀྍ⬟࡛࠶ࡿ. ࡋࡋ࡞ࡀࡽ, ᱂ᇵ✀ࡢከࡃࡣ, ẚ㍑ⓗ㧗࠸pH (pH > 5)୰ࡉࢀࡓᅵ ተ࡛ࡶ⏕⫱ࡣ㜼ᐖࡉࢀࡿ (Kinraide and Parker, 1990; Yokota and Ojima, 1995). ࡲࡓ, ୰
⏝࠸ࡽࢀࡿ▼⅊ཬࡧⅣ㓟࢝ࣝࢩ࣒࢘ (CaCO3)ࡢCa⫧ᩱࡣ, ⏕⫱㜼ᐖࢆ㍍ῶࡍࡿࡀ, ◲ 㓟࢝ࣝࢩ࣒࢘ (CaSO4)ࢆᡂศࡍࡿ▼⭯ࡢࡼ࠺࡞ࣝ࢝ࣜࢆᘬࡁ㉳ࡇࡉ࡞࠸ Ca ⫧ᩱ
࡛ࡶ✐≀ࡢ⏕⏘ᛶࡣᨵၿࡉࢀࡿ (Carvalho and vanRaij, 1997; Mora et al., 1999). ࡇࢀࡽ
㓟ᛶᅵተࡢᖜᗈ࠸ᅵተpH࡛ࡢAl3+, H+ẘᛶࡸCa≧ែࡀཬࡰࡍ᳜≀⏕⫱ࡣ, ⏕⌮Ꮫⓗཬࡧ ศᏊ⏕⌮Ꮫⓗ༑ศ⌮ゎࡉࢀ࡚࠸ࡿࢃࡅ࡛ࡣ࡞࠸.
ࡑࡇ࡛, ࢤࣀ࣒㓄ิỴᐃࡉࢀࡓࢩࣟࢾࢼࢬࢼ㔝⏕ᰴ࢚ࢥࢱࣉ (Clark et al., 2007)
ࡘ࠸࡚, ẚ㍑ⓗ㧗࠸pH᮲௳࡛ࡢAl3+, H+ឤཷᛶࢆẚ㍑ࡋࡓ (Kobayashi et al., in press;
Fig. 18). ࡇࢀࡽ᮲௳࡛ࡢ㔝⏕ᰴ࢚ࢥࢱࣉ࡛ࡢ㜼ᐖࡣ, ឤཷᛶኚ␗ᰴࢆ⏝࠸ࡿࡼࡾࡶ, ẚ
㍑ⓗ㧗࠸pHࡢ㓟ᛶᅵተ࡛ࡢ᱂ᇵ✀ࡢ㜼ᐖ㏆࠸ࡣࡎ࡛࠶ࡿ. pH 5.2ࡢǍ0$OࢆྵࡴỈ⪔
⁐ᾮ࡛ࡢ᰿㛗ࡀࢥࣥࢺ࣮ࣟࣝ⁐ᾮ (pH 5.2ࡢAlࢆྵࡲ࡞࠸⁐ᾮ)ẚ㍑ࡋ࡚㜼ᐖࡉࢀ࡚࠸
ࡿ㔝⏕ᰴ࢚ࢥࢱࣉࡀ☜ㄆࡉࢀࡓ. ࡲࡓ, pH 5.0࡛ࡢ᰿㛗ࡀpH 5.5ẚ㍑ࡋ࡚㜼ᐖࡉࢀ࡚࠸
ࡿ㔝⏕ᰴ࢚ࢥࢱࣉࡶ᫂ࡽ࡞ࡗࡓ (Fig. 18). ᚑࡗ࡚, ࡇࡢࡼ࠺࡞㓟ᛶᅵተ᮲௳࡛ࡢAl ཬࡧH+ẘᛶࣞ࣋ࣝឤཷᛶࢆ♧ࡍ㔝⏕ᰴ࢚ࢥࢱࣉࡢᏑᅾࡀᨭᣢࡉࢀࡿ. Lov-5 Bay-0 ࡣ, Ỉ⪔ヨ㦂࡛ࡢ᰿㛗㜼ᐖࡼࡾ, ྠ⛬ᗘࡢAlឤཷᛶࢆ♧ࡍࡀ, Lov-5ࡣpH 5࡛Bay-0ࡼࡾ
ࡶឤཷᛶࢆ♧ࡋࡓ. CaCO3ࢆ⫧ࡋ࡚pH 5.1ㄪᩚࡋࡓ㓟ᛶ㯮࣎ࢡᅵ (100 g࠶ࡓࡾ0.15 g ࡢCaCO3ࢆ⫧)࡛, Lov-5ࡢ⏕⫱ࡣBay-0ࡼࡾࡶ㜼ᐖࡉࢀࡓ. ⁐ゎᗘࡢ㧗࠸CaSO4ࢆࡉࡽ
ῧຍࡋࡓᅵተ (pH 5.0)࡛ࡣ, Lov-5ࡢH+ឤཷᛶࡣ㍍ῶࡉࢀࡓ. ᑦ, Alឤཷᛶ࡛࠶ࡿBay-0 ࡢ⏕⫱ࡶᨵၿࡀㄆࡵࡽࢀࡓ (Fig. 18). ࡇࡢpH 5.1ࡢ㓟ᛶ㯮࣎ࢡᅵࡣ, ឤཷᛶ࢚ࢥࢱࣉ
ᐖ࡞ࡿAl3+ཬࡧH+ẘᛶࣞ࣋ࣝࢆྵࢇ࡛࠾ࡾ, pHࢆୖ᪼ࡉࡏ࡞࠸▼⭯ࡣࡑࢀࡽẘᛶࢆ㍍ῶ ࡉࡏࡿࡇࢆ♧ࡋ࡚࠸ࡿ.㟼㟁ⓗࣔࢹࣜࣥࢢࡢ᳨ド࠶ࢃࡏ࡚, ࡇࡢࡼ࠺࡞㓟ᛶᅵተ࡛ࡢẘ ᛶཬࡧCa㍍ῶࡣ, {Al3+}PM, {H+}PM, {Ca2+}PM࡛ㄝ࡛᫂ࡁࡿ⪃࠼ࡽࢀࡿ. ᚑࡗ࡚, ⫧ཬࡧ
᳜≀ࡢ㑇ఏᙧ㉁ࡢࡘࡢ᪉㠃࡛㟼㟁ⓗࣔࢹࣜࣥࢢࡼࡿ Ca ≧ែࢆ⪃៖ࡍࡿࡇࡀ㓟ᛶᅵ ተ࡛ࡢ⫱✀ࡢⓎᒎᮇᚅ࡛ࡁࡿ.
」ᩘࡢࢩࢢࢼࣝᅉᏊᛂ⟅ࡍࡿAtALMT1Ⓨ⌧ࡣ, Al⪏ᛶࡢ⋓ᚓ᳜≀ཎ⳦ࡢᢠ
˩0$O&ODWS+
S+
5HODWLYHURRWOHQJWKRIFRQWURO
* * *
* *
* *
* *
* *
* *
* *
*
A *
B
Bay-0
g /100 g soil
CaCO3 0.40 0.15 0.15
CaSO4 0.0 0.0 0.20
pH (H2O) 5.5 5.1 5.0
Lov-5
1ID )HL &RO %XU 6KD 7DPP /HU 7V & 9DQ %RU (VW /RY 7VX *RW %D\
1ID )HL &RO %XU 6KD 7DPP /HU 7V & 9DQ %RU (VW /RY 7VX *RW %D\
Figure 18.Comparison of sensitivity of Arabidopsis accessions to Al3+and H+rhizotoxicities at pH 5.0. A) Seedlings were grown hydroponically for 7 d in slightly H+-toxic (pH 5.0) and Al3+-toxic (2PM AlCl3at pH 5.2) solutions and were compared with seedlings grown in the control solutions (Al control: pH 5.2 and zero Al; pH control: pH 5.5 and zero Al).
Means of relative valuesrSE (n = 6) are indicated. Asterisks denote a significant difference between the root length of seedlings grown in the toxic solutions compared with those grown in the control solutions (*P< 0.05, Student’s t-test). B) Lov-5 and Bay-0 accessions grown for four weeks on acidic andosol fertilized with CaCO3 or combinations of CaCO3 and CaSO4. Soil pH (H2O) was also indicated. White bar = 1 cm.
ᛶࢆㄏᑟࡍࡿࡓࡵࡢ᭷⏝᰿ᅪ⣽⳦ࡢ㞟✚ࡢከ㠃ⓗ࡞ᶵ⬟㔜せ࡞ᙺࢆᯝࡓࡋ࡚࠸ࡿ⪃
࠼ࡽࢀࡿ. ࡇࢀࡽ⪏ᛶࡢ㘽࡞ࡿࡢࡣ᰿ᅪࡢࣜࣥࢦ㓟ᨺฟ࡛࠶ࡾ, ⫱✀ࡼࡿ⪏ᛶࡢᨵ Ⰻࡢࡓࡵࡢ㔜せ࡞ᙧ㉁࡞ࡿ. AtALMT1Ⓨ⌧ࡢᨵኚࡣ, 」ᩘࡢࢫࢺࣞࢫ⪏ᛶࢆᣢࡓࡏࡿศ Ꮚ⫱✀ࡢᡭἲࡢ1ࡘࡋ࡚ᮇᚅ࡛ࡁࡿ.
ࡇࢀࡲ࡛, ࢥ࣒ࢠALMT1 (TaALMT1)ࢆ᳜≀✀ࡢ୰࡛Alឤཷᛶ✀࡛࠶ࡿ࣒࢜࢜ࢠᑟ ධࡍࡿࡇ࡛Al⪏ᛶࢆ㧗ࡵࡿࡇࡀሗ࿌ࡉࢀ࡚࠸ࡿ (Delhaize et al., 2004). TaALMT1㐣
Ⓨ⌧࣒࢜࢜ࢠ (cv. Golden Promise)ࡢ㓟ᛶᅵተ࡛ࡢ⏕⫱ࡣ, Al⪏ᛶࢥ࣒ࢠရ✀ྠ⛬ᗘ ࡢ⪏ᛶࢆ♧ࡋࡓ. ࡇࢀࡣ, ᙧ㉁㌿࣒࢜࢜ࢠ࡛ࡢTaALMT1ࡢ␗ᡤⓗ࡞Ⓨ⌧ࡀ, ࣜࣥࢦ㓟ᨺ ฟࢆᮏ᮶ᣢࡓ࡞࠸᳜≀యࣜࣥࢦ㓟ᨺฟ⬟ຊࢆࡋࡓࡇࡼࡿ.
ࡑࡇ࡛, CaMV 35Sࣉ࣮ࣟࣔࢱ࣮࡛AtALMT1ࢆCol-0㐣Ⓨ⌧ࡉࡏࡓᙧ㉁㌿య࡛ࡢ
ྛࢫࢺࣞࢫࡢ⪏ᛶຠᯝࡀホ౯ࡉࢀࡓ (Kobayashi et al., in press; Fig. 19). AtALMT1ࡣ
Col-0࡛ࡣAlࡼࡾㄏᑟࡉࢀࡿࡀ, 㐣Ⓨ⌧య࡛ࡣAlࢆྵࡲ࡞࠸ࢥࣥࢺ࣮ࣟࣝ᮲௳࡛ࡶᜏ
ᖖⓗⓎ⌧ࡉࢀ࡚࠸ࡓ (Fig. 19A). 㐣Ⓨ⌧యࡢAlฎ⌮ࡼࡿࣜࣥࢦ㓟ᨺฟࡣ, 㔝⏕ᰴ
ẚ㍑ࡋ࡚5-10ಸቑຍࡋ࡚࠸ࡓ (Fig. 19B). 㐣Ⓨ⌧యࡢࣜࣥࢦ㓟ᨺฟࡣ, ࢥࣥࢺ࣮ࣟࣝ᮲
௳࡛ࡶ㔝⏕ᰴẚ㍑ࡋ࡚࠾ࡼࡑ 3 ಸቑຍࡋ࡚࠾ࡾ, ᰿࡛ࡢࣜࣥࢦ㓟㉮ᛶࢆ♧ࡍ᭷⏝᰿ᅪ
⣽ ⳦ B. subtilis strain FB17 ࡢ ࡼ ࡾ ከ ࡃ ࡢ ᐃ ╔ ࡀ ㄆ ࡵ ࡽ ࢀ ࡓ (Fig. 19C). ᚑ ࡗ ࡚, AtALMT1ࡢ㐣Ⓨ⌧ࡣ, 㔝⏕ᰴᮏ᮶ࡢࣜࣥࢦ㓟ᨺฟ⬟ຊࢆ㧗ࡵ, ᭷⏝⣽⳦ࡢ㞟✚᭷ຠ࡛
࠶ࡗࡓ. ࡋࡋ࡞ࡀࡽ, Alฎ⌮ࡼࡿ᰿㛗㜼ᐖ࠾࠸࡚, Alㄏᑟࡼࡿࣜࣥࢦ㓟ᨺฟࡀ࠾ࡼ
ࡑ10ಸ࡛࠶ࡗࡓ⊂❧ࡋࡓ㐣Ⓨ⌧యࡢ1ࡘࡣ, 㔝⏕ᰴࡼࡾࡶ᭷ព⪏ᛶࢆ♧ࡋࡓࡀ, 5ಸ⛬
ᗘࡢ㐣Ⓨ⌧యࡣ㔝⏕ᰴྠ⛬ᗘࡢ㜼ᐖࢆ♧ࡋࡓ (Fig. 19D). ࡲࡓ, ࡼࡾከࡃࡢFB17ࡀ㞟
✚ࡉࢀࡿ㐣Ⓨ⌧యࡢPst DC3000ឤᰁᑐࡍࡿᚩࡣ, Col-0ẚ㍑ࡋ࡚ࢃࡎᨵၿࡉ
ࢀࡓ (Fig. 19E). AtALMT1-KO࡛ࡣ, Al᰿㛗㜼ᐖཬࡧFB17᥋✀࡛ࡢPst DC3000ឤᰁ
ᑐࡍࡿᚩࡶ῝้࡛࠶ࡾ, AtALMT1ࡀࡑࢀࡒࢀࡢࢫࢺࣞࢫᑐࡍࡿ⪏ᛶᚲ㡲࡛࠶
ࡿࡇࡣ᫂ⓑ࡛࠶ࡿ.
MockFB17PstDC3000 +FB17
Col-0
AtALMT1-KO 35S-AtALMT1/
Col-0
Col-0
AtALMT1-KO 35S-AtALMT1/
Col-0
MockFB17PstDC3000 +FB17
0 10 20 30 40 50 60 70
Relative root length in Al solution (%)
35S-AtALMT1/
Col-0 0
5 10 15
Malate release (nmol/plant/12h)
35S-AtALMT1/
Col-0
B
D
C
E
a
b b
c AtALMT1
UBQ1
-Al +Al
A
Col-0 #5 #11 35S-AtALMT1/
Col-0
Col-0
Figure 19.Overexpression analysis ofAtALMT1in Arabidopsis wild-type Col-0. A) Expression of AtALMT1in the roots of Col-0 and transgenic Col-0 carrying CaMV 35S-drivenAtALMT1 (35S-AtALMT1/Col-0) with or without Al.UBQ1was used as the internal standard. B) Malate exudation from the roots of Col-0 and 35S-AtALMT1/Col-0. Seedlings aseptically grown for 5 d in MGRL containing 1% sucrose were then incubated in 2% MGRL in the presence or absence of 10ȝ0 AlCl3 for 12 h. Meanss SD are shown (n= 3). C)B. subtilisstrain FB17 colonization on the roots of Col-0, 35S-AtALMT1/Col-0, andAtALMT1-KO (SALK_009629). Three-week-oldin vitro seedlings were foliar sprayed withPst DC3000 (OD600= 0.1), or an equal volume of water as the control (Mock), and rhizoinoculated with or without FB17 (OD600 = 0.001) for 24 h. The roots were stained with SYTO®13 (Invitrogen, Molecular Probes, Eugene, OR) to allow viewing of adherent FB17 cells on the root surface. Bar indicates 50ȝP. D) Al-induced root growth inhibiton of Col-0, 35S-AtALMT1/Col-0, and AtALMT1-KO. Seedlings were hydroponically grown in 2%
MGRL in the presence or absence of 6ȝ0AlCl3(pH 5.0) for 5 d. Means of relative root length (%
of –Al) are shown (n= the longest 10 roots from 25 seedlings). Different letters indicate significant differences (Tukey’s test, P < 0.05). E) Disease symptoms on Col-0, 35S-AtALMT1/Col-0, and AtALMT1-KO plants after being inoculated with Pst DC3000 and rhizoinoculated with FB17.
Three-week-old seedlings were infiltrated withPst DC3000 (OD600= 0.1) or an equal volume of water as the control (Mock), and rhizoinoculated with or without FB17 (OD600 = 0.001). The disease symptoms were observed after 72 h of infection.
ࡇࢀࡽࡢ⤖ᯝࡘ࠸࡚, 㐣Ⓨ⌧యࡢ㔝⏕ᰴࣂࢵࢡࢢࣛ࢘ࣥࢻࡢ₯ᅾⓗ࡞⬟ຊࡀ⪏ᛶ
㛵㐃ࡍࡿணࡉࢀࡿ. Col-0ࡣ, ࢚ࢥࢱࣉࡢ୰࡛ࡶᙉ࠸Al⪏ᛶࢆ♧ࡋ, ࣜࣥࢦ㓟ᨺฟ⬟
ຊࡀ㧗࠸ (Kobayashi et al., 2007). Col-0ࡢ₯ᅾⓗ࡞ࣜࣥࢦ㓟ᨺฟࡣ, Al⪏ᛶཬࡧFB17ࢆ
ࡋࡓᢠᛶࡢㄏᑟᑐࡋ࡚᪤㣬ࡋ࡚࠸ࡿ࡛ࣞ࣋ࣝ࠶ࡿ⪃࠼ࡽࢀࡿ. ࡼࡗ࡚, ࣜࣥ
ࢦ㓟ᨺฟ⬟ຊࡢప࠸Ler-0ࡢ㐣Ⓨ⌧ࡣ, ⪏ᛶࢆᙉࡍࡿྍ⬟ᛶࡀ࠶ࡿ.
༢⣧࡞㐣Ⓨ⌧ࡼࡿᡭἲ࡛ࡶ, AtALMT1ࡢᣢࡘከ㠃ⓗ࡞⪏ᛶᶵᵓࢆ࡛ࡁࡿྍ⬟ᛶ ࡀ࠶ࡿࡇࡀ♧ࡉࢀࡓ. ࡇࡢከ㠃ⓗ࡞ᶵ⬟ࡼࡿ⪏ᛶࡢ⋓ᚓࡣ, AtALMT1Ⓨ⌧ࡔࡅ࡛࡞
ࡃ AtALMT1 άᛶࡶᗄࡘࡢࢩࢢࢼࣝᅉᏊࡢ㛵ࡍࡿไᚚᶵᵓࢆࡍࡿࡇࡀ⪃࠼ࡽࢀ
ࡓ. 㐣Ⓨ⌧ࡼࡿຠᯝᐟࡢ⬟ຊࡀ౫Ꮡࡍࡿࡉࢀࡿࡇࡣ, ࡑࢀࡒࢀࡢไᚚᶵᵓࡢ άᛶࣞ࣋ࣝࡘ࠸࡚, ࢚ࢥࢱࣉ㛫ࡢᕪࡀᙳ㡪ࡍࡿࡶࡋࢀ࡞࠸. ᚑࡗ࡚, ࡑࢀࡽࢆ᳨ド ࡍࡿࡓࡵᮏ◊✲࡛᫂ࡽ࡞ࡗࡓᗄࡘࡢࢩࢢࢼࣝᅉᏊᛂ⟅ᛶࡘ࠸࡚ヲ⣽࡞ゎᯒࡀᚲ せࡉࢀࡿ.
ᚋ, ࣇ࣮ࣝࢻヨ㦂࡛⏕ࡌࡿ⤖ᯝࡘ࠸࡚, ᅵተ⁐ᾮᑐࡍࡿ᳜≀ࡢศᏊ࡛ࣞ࣋ࣝࡢ ᛂ⟅ࢆ㟼㟁ⓗࣔࢹࣜࣥࢢࡼࡾ⤖ࡧࡘࡅࡿࡇࡀ࡛ࡁ, ᐇ㦂ᐊ࡛ࣞ࣋ࣝࡢゎᯒ࡛ド᫂ࡉࢀ
ࡓᶵᵓࢆ㐺ྜࡉࡏࡿࡇࡀྍ⬟࡞ࡿ. ᮏ◊✲ࡣ, AtALMT1Ⓨ⌧ࡢไᚚᶵᵓࢆᐇ㝿ࡢࢫࢺ
ࣞࢫᅵተ࡛ࡼࡾຠᯝⓗᶵ⬟ࡉࡏࡿࡓࡵࡢࣔࢹࣝ࡞ࡿᛮࢃࢀࡿ.
⤖ㄽ
⤖ㄽࡋ࡚, ࢩࣟࢾࢼࢬࢼ࡛ࡢ᰿ẘᛶ࢜ࣥࡢ㞀ᐖཬࡧ Caࡼࡿ㍍ῶࡣ, ࡇࢀࡲ࡛ࡢ ゎᯒྠᵝ, ᰿ఙ㛗㜼ᐖࢆᇶ‽ࡋ, SGCS ࡛ࡢࣔࢹࣜࣥࢢࡼࡿ{Al3+}PM, {H+}PM, {Ca2+}PMࢆ⏝࠸࡚ホ౯࡛ࡁࡓ. ࡉࡽ, Alᛂ⟅ࣂ࣐࣮࣮࢜࢝㑇ఏᏊཬࡧ⪏ᛶ㑇ఏᏊࡢᛂ⟅
ゎᯒ࡛♧ࡉࢀࡓ⤖ᯝࡶࡇࡢࣔࢹࣜࣥࢢᙉࡃ㛵㐃ࡍࡿࡇࡀ♧ࡉࢀࡓ. ࡇࡢ㟼㟁ⓗࣔࢹࣝ
ࡣ, ࣜࣥḞஈ᮲௳࡛PMࡢ㈇㟁Ⲵࡀ㧗ᐦᗘಖࡓࢀࡿpah1pah2ࡢࣜࣥḞஈ᮲௳࡛ࡢAlឤ
ཷᛶ⾲⌧ᆺࡼࡗ࡚ᨭᣢࡉࢀࡓ. ᚑࡗ࡚, PM࡛ࡢ᰿ẘᛶ࢜ࣥ(Al3+, H+)ཬࡧCa2+ࡢ㟼㟁
ⓗ࡞┦స⏝ࢆGEOCHEM-EZSpeciation Gouy-Chapman Sternࣔࢹࣝࢆ⤌ࡳྜࢃࡏ ࡓ㟼㟁ⓗࣔࢹࣝࡼࡾ᥎ᐃࡋ, ࡇࢀࢆᣦᶆࡋࡓゎᯒࡣ, ศᏊ⏕⌮Ꮫⓗᛂ⟅ࡢ⌮ゎ᭷ຠ
࡞ᡭἲ࡞ࡿࡇࢆ♧ࡋࡓ.
ࡲࡓ, AtALMT1ࡣ, IAA, ABA, పpH, H2O2ཬࡧflg22࡛ฎ⌮ࡉࢀࡓ㔝⏕ᰴ᰿㒊࡛ㄏᑟࡉ
ࢀࡓ. ᪤▱ࡢࢩࢢࢼࣝኚ␗ᰴཬࡧࣂ࣐࣮࣮࢜࢝㑇ఏᏊࢆ⏝࠸࡚, Al ཬࡧ flg22 ࡼࡿ
AtALMT1ࡢㄏᑟࡣ, IAA, ABAࡼࡾάᛶࡉࢀࡿࢩࢢࢼࣝఏ㐩⤒㊰ࢆᚲせࡋ࡚࠸࡞࠸
ࡇࢆ᫂ࡽࡋࡓ. ࡉࡽ, AtALMT1ࣉ࣮ࣟࣔࢱ࣮ࡼࡿAtALMT1Ⓨ⌧ࡢࢩࢫไᚚࡣ, ABAAlࢆྵࡴࡢࢩࢢࢼࣝᅉᏊ࡛␗࡞ࡿࡇࢆ♧ࡋࡓ. ࡇࡢᛂ⟅ᛶࡣ, 㠀⏕≀ⓗཬࡧ
⏕≀ⓗࢫࢺࣞࢫᑐࡍࡿ AtALMT1 ࡢᣢࡘከ㠃ⓗ࡞ᶵᵓࢆㄝ࡛᫂ࡁࡿ⪃࠼ࡽࢀࡿ. ࡋ
ࡋ࡞ࡀࡽ, ࡇࡢከ㠃ᛶࢆᢕᥱࡍࡿࡓࡵࡣ, Ⓨ⌧ไᚚࡔࡅ࡛࡞ࡃ, AtALMT1 ࢆࡋࡓࣜࣥ
ࢦ㓟ᨺฟࡢάᛶࡘ࠸࡚ࡶ, ࡢࡼ࠺࡞ࢩࢢࢼࣝࡀ㛵ࡋ࡚࠸ࡿࡢࢆ⪃៖ࡍࡿᚲせࡀ
࠶ࡿ.
ㅰ㎡
ࡇࡢࡼ࠺࡞⣲ᬕࡽࡋ࠸ࢸ࣮࣐ࢆ࠼࡚ࡃࡔࡉࡾ㸪┤᥋ࡢᚚᣦᑟ࡞ࡽࡧ㈗㔜࡞ᚚຓゝࢆ
㡬ࡁࡲࡋࡓᒱ㜧Ꮫᛂ⏝⏕≀⛉Ꮫ㒊ᩍᤵ ᑠᒣ༤அ༤ኈཌࡃᚚ♩⏦ࡋୖࡆࡲࡍ㸬ᮏ◊✲ࡢ
⏕⌮Ꮫⓗࢹ࣮ࢱࢆ⋓ᚓࡍࡿ࠶ࡓࡾ㸪㐺ษᣦᑟࡋ࡚࠸ࡓࡔ࠸ࡓᒱ㜧Ꮫᛂ⏝⏕≀⛉Ꮫ㒊
ຓᩍ ᑠᯘభ⌮Ꮚ༤ኈཌࡃᚚ♩⏦ࡋୖࡆࡲࡍ㸬ࡲࡓ, SGCS ࣉࣟࢢ࣒ࣛཬࡧࡑࡢࣉࣟࢢࣛ
࣒ࢆ⏝࠸ࡓࢹ࣮ࢱゎᯒࢆᣦᑟࡋ࡚࠸ࡓࡔ࠸ࡓ⡿ᅜ㎰ົ┬ࣃࣛࢳ㎰ᴗࢩࢫࢸ࣒◊✲ࢭࣥ
ࢱ࣮ Thomas B. Kinraide༤ኈᚚ♩⏦ࡋୖࡆ࠶ࡲࡍ.
ᮏ◊✲࡛⏝⮴ࡋࡲࡋࡓ㑇ఏᏛⓗᮦᩱࢆᥦ౪ࡋ࡚࠸ࡓࡔࡁࡲࡋࡓ⌮Ꮫ◊✲ᡤࣂ࢜ࣜ
ࢯ࣮ࢫࢭࣥࢱ࣮ ෆ⪷༤ኈ, ᮾிᕤᴗᏛࣂ࢜◊✲ᇶ┙ᨭࢭࣥࢱ࣮ᩍᤵ ኴ⏣ၨஅ༤ ኈ, ⌮Ꮫ◊✲ᡤ᳜≀ච◊✲ࢢ࣮ࣝࣉ ⓑ㡲㈼༤ኈ, ࡲࡓ, ICP-MSࡼࡿAlࡢྵ㔞 ᐃ
ࢆࡋ࡚㡬ࡁࡲࡋࡓᾏ㐨ᏛᏛ㝔㎰Ꮫ◊✲㝔ᩍᤵ Ώ㒊ᩄ⿱༤ኈཌࡃᚚ♩⏦ࡋ࠶ࡆࡲ
ࡍ㸬
ࡉࡽᖖ ࡃᛂࡋ࡚ࡃࡔࡉࡗࡓ᳜≀⣽⬊ᕤᏛ◊✲ᐊࡢⓙᵝឤㅰ⮴ࡋࡲࡍ㸬᭱ᚋ
㸪Ꮫ⏕⏕άࢆ⤒῭ⓗ㸪⢭⚄ⓗᨭ࠼࡚㡬ࡁࡲࡋࡓ୧ぶ㸪ጜᚰࡽឤㅰ⮴ࡋࡲࡍ㸬
ᘬ⏝ᩥ⊩
A
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