Cucumber malate decarboxylase, CsNADP-ME2, functions in the balance of carbon and amino acid metabolism in fruit.
Cucumber malate decarboxylase, CsNADP-ME2, functions in the balance of carbon and amino acid metabolism in fruit.
复制标题
黄瓜苹果酸脱羧酶（CsNADP-ME 2）在果实碳和氨基酸代谢平衡中起重要作用。
DOI：
10.1093/hr/uhad216
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发表时间：
2023-12
影响因子：
8.7
通讯作者：
中科院分区：
文献类型：
--
作者：
中枢代谢产生与植物生长密切相关的碳水化合物和氨基酸，从而提高作物产量。据报道，苹果酸连接线粒体呼吸代谢与胞质生物合成途径。虽然苹果酸代谢相关酶在提供碳的功能已在一些植物中得到表征，但在黄瓜肉质果实中缺乏这种作用的证据。在这里，放射性标记的碳酸氢根进料到木质部流从黄瓜根被纳入氨基酸，可溶性糖，和有机酸的外果皮和脉管系统的水果。黄瓜果实中的脱羧酶活性，尤其是NADP依赖的苹果酸酶（NADP-ME）脱羧活性高于叶片。组织化学定位结果表明，CsNADP-ME 2主要定位于果实的外果皮和维管束系统中。放射性示踪和气体交换分析表明，CsNADP-ME 2的过表达可以促进果实中的碳通量转化为可溶性糖和淀粉。结合代谢谱的进一步研究表明，CsNADP-ME 2在RNA干扰（RNAi）系中的下调导致其底物苹果酸在外果皮中的积累。除了糖酵解相关基因表达的抑制和相应酶活性的降低外，在这些品系中还观察到氨基酸合成增加和糖丰度降低。在CsNADP-ME 2过表达的细胞系中发现了相反的效应，这表明黄瓜果实中糖酵解可能存在一种持续的自下而上的反馈调节。综上所述，CsNADP-ME 2可能在黄瓜果实的中心碳反应和氨基酸代谢中发挥重要作用。
Central metabolism produces carbohydrates and amino acids that are tightly correlated to plant growth and thereby crop productivity. Malate is reported to link mitochondrial respiratory metabolism with cytosolic biosynthetic pathways. Although the function of malate metabolism-related enzymes in providing carbon has been characterized in some plants, evidence for this role in the fleshy fruit of cucumber is lacking. Here, radiolabeled bicarbonate fed into the xylem stream from the cucumber roots was incorporated into amino acids, soluble sugars, and organic acids in the exocarp and vasculature of fruits. The activities of decarboxylases, especially decarboxylation from NADP-dependent malic enzyme (NADP-ME), were higher in cucumber fruit than in the leaf lamina. Histochemical localization revealed that CsNADP-ME2 was mainly located in the exocarp and vascular bundle system of fruit. Radiotracer and gas-exchange analysis indicated that overexpression of CsNADP-ME2 could promote carbon flux into soluble sugars and starch in fruits. Further studies combined with metabolic profiling revealed that the downregulation of CsNADP-ME2 in RNA interference (RNAi) lines caused the accumulation of its substrate, malate, in the exocarp. In addition to inhibition of glycolysis-related gene expression and reduction of the activities of the corresponding enzymes, increased amino acid synthesis and decreased sugar abundance were also observed in these lines. The opposite effect was found in CsNADP-ME2-overexpressing lines, suggesting that there may be a continuous bottom-up feedback regulation of glycolysis in cucumber fruits. Overall, our studies indicate that CsNADP-ME2 may play potential roles in both central carbon reactions and amino acid metabolism in cucumber fruits.
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影响因子：
5.6
作者：
Baslam M;Mitsui T;Sueyoshi K;Ohyama T
通讯作者：
Ohyama T
影响因子：
5.6
作者：
Arias CL;Pavlovic T;Torcolese G;Badia MB;Gismondi M;Maurino VG;Andreo CS;Drincovich MF;Gerrard Wheeler MC;Saigo M
通讯作者：
Saigo M
影响因子：
6.9
作者：
Hebbelmann I;Selinski J;Wehmeyer C;Goss T;Voss I;Mulo P;Kangasjärvi S;Aro EM;Oelze ML;Dietz KJ;Nunes-Nesi A;Do PT;Fernie AR;Talla SK;Raghavendra AS;Linke V;Scheibe R
通讯作者：
Scheibe R
影响因子：
4.3
作者：
Hu, Li-Ping;Meng, Fan-Zhen;Zhang, Zhen-Xian
通讯作者：
Zhang, Zhen-Xian
通过过氧化物酶体乙酸-苹果酸分流调节保卫细胞的膨压和耐旱性。
影响因子：
27.5
作者：
Dong, Huan;Bai, Ling;Song, Chun-Peng
通讯作者：
Song, Chun-Peng