PDF(Pubmed)
Abstract：
Bacillus subtilis 26D is a plant growth-promoting endophytic bacteria capable of inducing systemic resistance through the priming mechanism, which includes plant genome reprogramming and the phenomenon of RNA interference (RNAi) and microRNA (miRNAs). The phloem-feeding insect bird cherry-oat aphid Rhopalosiphum padi L. is a serious pest that causes significant damage to crops throughout the world. However, the function of plant miRNAs in the response to aphid infestation remains unclear. The results of this work showed that B. subtilis 26D stimulated aphid resistance in wheat plants, inducing the expression of genes of hormonal signaling pathways ICS, WRKY13, PR1, ACS, EIN3, PR3, and ABI5. In addition, B. subtilis 26D activated the RNAi mechanism and regulated the expression of nine conserved miRNAs through activation of the ethylene, salicylic acid (SA), and abscisic acid (ABA) signaling pathways, which was demonstrated by using treatments with phytohormones. Treatment of plants with SA, ethylene, and ABA acted in a similar manner to B. subtilis 26D on induction of the expression of the AGO4, AGO5 and DCL2, DCL4 genes, as well as the expression of nine conserved miRNAs. Different patterns of miRNA expression were found in aphid-infested plants and in plants treated with B. subtilis 26D or SA, ethylene, and ABA and infested by aphids, suggesting that miRNAs play multiple roles in the plant response to phloem-feeding insects, associated with effects on hormonal signaling pathways, redox metabolism, and the synthesis of secondary metabolites. Our study provides new data to further elucidate the fine mechanisms of bacterial-induced priming. However, further extensive work is needed to fully unravel these mechanisms.
摘要：
枯草芽孢杆菌26D是一种促进植物生长的内生细菌，能够通过启动机制诱导系统抗性，其中包括植物基因组重编程和RNA干扰（RNAi）和microRNA（miRNA）现象。以韧皮部为食的昆虫鸟樱桃燕麦蚜虫RhopalosiphumpadiL.是一种严重的害虫，对全世界的农作物造成重大损害。然而,植物miRNAs在响应蚜虫侵染中的功能仍不清楚。这项工作的结果表明，枯草芽孢杆菌26D刺激了小麦植株的蚜虫抗性，诱导激素信号通路ICS的基因表达，WRKY13,PR1,ACS,EIN3、PR3和ABI5。此外,枯草芽孢杆菌26D激活RNAi机制并通过激活乙烯调节9个保守miRNAs的表达,水杨酸(SA),和脱落酸（ABA）信号通路，通过使用植物激素治疗得到了证明。用SA处理植物，乙烯,ABA与枯草芽孢杆菌26D对AGO4、AGO5和DCL2、DCL4基因表达的诱导相似，以及9种保守miRNA的表达。在蚜虫侵染的植物和用枯草芽孢杆菌26D或SA处理的植物中发现了不同的miRNA表达模式。乙烯,和ABA，被蚜虫感染，表明miRNAs在植物对韧皮部摄食昆虫的反应中起着多重作用，与对激素信号通路的影响有关，氧化还原代谢，和次生代谢产物的合成。我们的研究提供了新的数据，以进一步阐明细菌诱导的启动的精细机制。然而,需要进一步广泛的工作来完全解开这些机制。
