Carbon Metabolism and Bacteroid Functioning Are Involved in the Regulation of Nitrogen Fixation in Medicago truncatula Under Drought and Recovery
Carbon Metabolism and Bacteroid Functioning Are Involved in the Regulation of Nitrogen Fixation in Medicago truncatula Under Drought and Recovery
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DOI：
10.1094/mpmi-22-12-1565
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发表时间：
2009-12-01
影响因子：
3.5
通讯作者：
Gonzalez, Esther M.
中科院分区：
文献类型：
--
作者：
Larrainzar, Estibaliz;Wienkoop, Stefanie;Gonzalez, Esther M.
干旱胁迫下共生固氮（SNF）的调节是复杂的，尚未完全了解。在目前的工作中，参与根瘤C和N代谢的调节SNF在干旱和随后的复水处理的蒺藜苜蓿进行了分析，使用代谢组学和蛋白质组学的方法相结合。干旱诱导SNF率的减少和结节的代谢特征的重大变化，主要是氨基酸（Pro，His和Trp）和碳水化合物（蔗糖，半乳糖苷，棉子糖和海藻糖）的积累。这种积累与参与SNF和C代谢的类菌体蛋白水平的下降一致，沿着植物蔗糖合成酶1（SuSy1）水平的部分降低。与此相反，氮同化相关的酶的变化被发现与SNF的减少不相关，这表明这些酶不具有SNF的调节作用。与豌豆、大豆等其他豆科植物不同，干旱对大豆SNF的抑制作用与干旱胁迫对大豆SNF的抑制作用不同。截形虫似乎是由类菌体代谢和固氮能力的损害引起的，而不是呼吸底物的限制。
Regulation of symbiotic nitrogen fixation (SNF) during drought stress is complex and not yet fully understood. In the present work, the involvement of nodule C and N metabolism in the regulation of SNF in Medicago truncatula under drought and a subsequent rewatering treatment was analyzed using a combination of metabolomic and proteomic approaches. Drought induced a reduction of SNF rates and major changes in the metabolic profile of nodules, mostly an accumulation of amino acids (Pro, His, and Trp) and carbohydrates (sucrose, galactinol, raffinose, and trehalose). This accumulation was coincidental with a decline in the levels of bacteroid proteins involved in SNF and C metabolism, along with a partial reduction of the levels of plant sucrose synthase 1 (SuSy1). In contrast, the variations in enzymes related to N assimilation were found not to correlate with the reduction in SNF, suggesting that these enzymes do not have a role in the regulation of SNF. Unlike the situation in other legumes such as pea and soybean, the drought-induced inhibition of SNF in M. truncatula appears to be caused by impairment of bacteroid metabolism and N2-fixing capacity rather than a limitation of respiratory substrate.