Soybean NADP-Malic Enzyme Functions in Malate and Citrate Metabolism and Contributes to Their Efflux under Al Stress.
Soybean NADP-Malic Enzyme Functions in Malate and Citrate Metabolism and Contributes to Their Efflux under Al Stress.
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大豆 NADP-苹果酸酶在苹果酸和柠檬酸代谢中发挥作用，并有助于它们在铝胁迫下的流出
DOI：
10.3389/fpls.2017.02246
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发表时间：
2017
影响因子：
5.6
通讯作者：
You J
中科院分区：
文献类型：
--
作者：
Zhou Y;Yang Z;Xu Y;Sun H;Sun Z;Lin B;Sun W;You J
苹果酸的积累被认为可以平衡铝诱导的大豆根中柠檬酸的合成和流出。为了检验这一假设，我们比较了两种大豆基因型之间铝诱导的柠檬酸和苹果酸积累和流出的特征，并结合对推测编码胞质 NADP-苹果酸酶的 GmME1 的功能分析。济玉70和济玉62品种在Al处理8 h前，柠檬酸盐释放量相似，根伸长受到同样的抑制。 12 h时，济玉70开始分泌更多的柠檬酸，并表现出比济玉62更高的铝抗性。在铝处理 24 小时，吉玉 70 内部苹果酸和柠檬酸浓度持续增加。然而，济玉62在铝处理12小时时苹果酸浓度降低，在24小时时柠檬酸浓度降低。 GmME1 定位于细胞质，与胞质苹果酸酶 AtME2 和 SgME1 紧密聚集，并在根中组成型表达。 Al处理在24 h内诱导了济玉70比济玉62更高的NADP-苹果酸酶活性和GmME1表达水平。与野生型毛状根相比，毛状根中过表达 GmME1 (GmME1-OE) 产生了更高的 GmME1 表达水平，但无论有或没有 Al 处理，都没有改变假定的柠檬酸转运蛋白基因 GmAACT1 和 GmFRDL 或苹果酸转运蛋白基因 GmALMT1 的表达模式。在铝胁迫 4 小时时，GmME1-OE 显示出较高的柠檬酸盐和苹果酸盐内部浓度和外部流出量。 GmME1-OE毛状根的根尖中较浅的苏木精染色和较低的铝含量表明较强的铝抗性。综合实验结果表明，维持铝诱导的柠檬酸流出取决于大豆根尖中的苹果酸库。 GmME1 编码一种胞质苹果酸酶，该酶有助于增加内部苹果酸和柠檬酸浓度及其外部流出，从而赋予更高的铝抗性。
Malate accumulation has been suggested to balance Al-induced citrate synthesis and efflux in soybean roots. To test this hypothesis, characteristics of Al-induced accumulation and efflux of citrate and malate were compared between two soybean genotypes combining a functional analysis of GmME1 putatively encode a cytosolic NADP-malic enzyme. Similar amounts of citrate were released, and root elongation was equally inhibited before 8 h of Al treatment of Jiyu 70 and Jiyu 62 cultivars. Jiyu 70 began to secrete more citrate and exhibited higher Al resistance than did Jiyu 62 at 12 h. A sustained increase in internal malate and citrate concentrations was observed in Jiyu 70 at 24 h of Al treatment. However, Jiyu 62 decreased its malate concentration at 12 h and its citrate concentration at 24 h of Al treatment. GmME1 localized to the cytoplast and clustered closely with cytosolic malic enzymes AtME2 and SgME1 and was constitutively expressed in the roots. Al treatment induced higher NADP-malic enzyme activities and GmME1 expression levels in Jiyu 70 than in Jiyu 62 within 24 h. Compared with wild-type hairy roots, over-expressing GmME1 in hairy roots (GmME1-OE) produced higher expression levels of GmME1 but did not change the expression patterns of either of the putative citrate transporter genes GmAACT1 and GmFRDL or the malate transporter gene GmALMT1, with or without Al treatment. GmME1-OE showed a higher internal concentration and external efflux of both citrate and malate at 4 h of Al stress. Lighter hematoxylin staining and lower Al contents in root apices of GmME1-OE hairy roots indicated greater Al resistance. Comprehensive experimental results suggest that sustaining Al-induced citrate efflux depends on the malate pool in soybean root apices. GmME1 encodes a cytosolic malic enzyme that contributes to increased internal malate and citrate concentrations and their external efflux to confer higher Al resistance.
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影响因子：
5.4
作者：
Gerrard Wheeler, Mariel C.;Arias, Cintia L.;Drincovich, Maria F.
通讯作者：
Drincovich, Maria F.
影响因子：
7.4
作者：
DELHAIZE, E;RYAN, PR;RANDALL, PJ
通讯作者：
RANDALL, PJ
影响因子：
4.9
作者：
Ma, JF;Zheng, SJ;Matsumoto, H
通讯作者：
Matsumoto, H
影响因子：
7.4
作者：
DELHAIZE, E;RYAN, PR
通讯作者：
RYAN, PR
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影响因子：
5.6
作者：
Haferkamp I;Schmitz-Esser S
通讯作者：
Schmitz-Esser S