Beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 Induces Plant Salt Tolerance through Spermidine Production
Beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 Induces Plant Salt Tolerance through Spermidine Production
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有益的根际细菌解淀粉芽孢杆菌 SQR9 通过产生亚精胺诱导植物耐盐性
DOI：
10.1094/mpmi-02-17-0027-r
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发表时间：
2017-05-01
影响因子：
3.5
通讯作者：
Zhang, Ruifu
中科院分区：
文献类型：
--
作者：
Chen, Lin;Liu, Yunpeng;Zhang, Ruifu
植物根际促生细菌接种是提高植物耐盐性以减少盐胁迫对农业生产力造成损失的有效策略，但盐胁迫下细菌向植物传递的信号尚不清楚。本研究通过接种解淀粉芽孢杆菌SQR9提高拟南芥和玉米的耐盐性。使用不同截留分子量的透析袋，我们对SQR9分泌的分子进行了分类，发现亚精胺是提高植物耐盐性的原因。一个SQR9 DspeB突变体亚精胺生产缺陷未能诱导植物耐盐性。然而，拟南芥中参与还原型谷胱甘肽（GSH）生物合成和盐过度敏感途径的基因突变破坏了植物耐盐性的诱导。使用定量实时聚合酶链反应，这项研究表明，由SQR9产生的亚精胺导致谷氨酰胺合成酶和谷胱甘肽还原酶基因表达增加，导致GSH水平增加，这对清除活性氧至关重要。SQR9衍生的亚精胺还上调NHX 1和NHX 7的表达，NHX 1和NHX 7将Na+隔离到液泡中并将Na+从细胞中排出，从而降低离子毒性。
The inoculation of plants with plant-growth-promoting rhizo-bacterium has been an effective strategy for enhancing plant salt tolerance to diminish the loss of agricultural productivity caused by salt stress; however, the signal transmitted from bacteria to the plant under salt stress is poorly understood. In this study, the salt tolerance of Arabidopsis thaliana and Zea mays was enhanced by inoculation with Bacillus amyloliquefaciens SQR9. Using dialysis bags with different molecular weight cutoffs, we sorted through the molecules secreted by SQR9 and found that spermidine is responsible for enhancing plant salt tolerance. An SQR9 DspeB mutant deficient in spermidine production failed to induce plant salt tolerance. However, the induction of plant salt tolerance was disrupted by mutating genes involved in reduced glutathione (GSH) biosynthesis and the salt overly sensitive pathway in Arabidopsis. Using quantitative real-time polymerase chain reaction, this study demonstrated that spermidine produced by SQR9 leads to increased glutamine synthetase and glutathione reductase gene expression, leading to increased levels of GSH, which is critical for scavenging reactive oxygen species. SQR9-derived spermidine also upregulates the expression of NHX1 and NHX7, which sequesters Na+ into vacuoles and expels Na+ from the cell, thereby reducing ion toxicity.