A Medicago truncatula ABC transporter belonging to subfamily G modulates the level of isoflavonoids
A Medicago truncatula ABC transporter belonging to subfamily G modulates the level of isoflavonoids
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DOI：
10.1093/jxb/ers380
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发表时间：
2013-02-01
影响因子：
6.9
通讯作者：
Jasinski, Michal
中科院分区：
文献类型：
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作者：
Banasiak, Joanna;Biala, Wanda;Jasinski, Michal
G亚家族（ABCG）的全长ATP结合盒（ABC）转运蛋白被认为是植物免疫系统的重要组成部分。这些蛋白质被认为与多种次级代谢产物的主动跨膜转运有关。尽管基于ABCG的运输对于植物微生物相互作用的重要性，但这些蛋白质在豆类中仍然很少被识别。本文所述的实验表明，蒺藜苜蓿ABCG 10（MtABCG 10）mRNA的水平升高后，真菌寡糖的应用到植物根。空间表达模式分析与报告基因显示，MtABCG10启动子是活跃在各种器官，主要是在他们的血管组织。相应的蛋白质定位于质膜。沉默MtABCG10在毛状根中导致苯丙烷途径衍生的medicarpin及其前体的积累较低。基于PCR的实验表明，感染尖孢镰刀菌，根感染病原体，在MtABCG10沉默的复合植物（由野生型芽转基因根）比相应的控制进展更快。基于所提供的数据，有人提出，在苜蓿，全尺寸ABCG转运蛋白可能会调节与从头合成的植物抗毒素防御反应过程中的抗氧化剂水平。
Full-sized ATP-binding cassette (ABC) transporters of the G subfamily (ABCG) are considered to be essential components of the plant immune system. These proteins have been proposed to be implicated in the active transmembrane transport of various secondary metabolites. Despite the importance of ABCG-based transport for plantmicrobe interactions, these proteins are still poorly recognized in legumes. The experiments described here demonstrated that the level of Medicago truncatula ABCG10 (MtABCG10) mRNA was elevated following application of fungal oligosaccharides to plant roots. Spatial expression pattern analysis with a reporter gene revealed that the MtABCG10 promoter was active in various organs, mostly within their vascular tissues. The corresponding protein was located in the plasma membrane. Silencing of MtABCG10 in hairy roots resulted in lower accumulation of the phenylpropanoid pathway-derived medicarpin and its precursors. PCR-based experiments indicated that infection with Fusarium oxysporum, a root-infecting pathogen, progressed faster in MtABCG10-silenced composite plants (consisting of wild-type shoots on transgenic roots) than in the corresponding controls. Based on the presented data, it is proposed that in Medicago, full-sized ABCG transporters might modulate isoflavonoid levels during the defence response associated with de novo synthesis of phytoalexins.