生防细菌Z26成功定殖油茶根系的分子机理研究

The crucial factor of biocontrol bacteria application is successfully colonization. We have screemed a biocontrol bacteria Brevibacillus brevis Z26 from the Camellia oleifera root soil. The control effect of Z26 was up to 75% in the field（ZL 201110027957.1；ZL 201310203845.6）. Approach the mechanism of colonization is the crucial for Z26 biocontrol efficacy. Using B. brevis Z26 and C. oleifera as object, combined with techniques such as fluorescent microscope technique, De Nove sequencing, RT-PCR, gene knock-out, the program will observe the Z26 distribution and transporting in C. oleifera root, explore the PAMP-triggered immunity which induced by Z26, verify the determinant secretion system function of Z26 responding PTI. Therefore, the molecular mechanism of Z26 colonization will be uncovered. The results will contribute to raise the B. brevis Z26 utilization efficiency and has important significance in fundamental research of biocontrol bacteria -plant interaction.

成功定殖是生防细菌稳定发挥功效的决定性因素。课题组前期从油茶根际土壤中分离筛选到一株高效生防短短芽孢杆菌Z26，对油茶主要病害的林间防效达到75%以上（ZL 201110027957.1；ZL 201310203845.6）。稳定Z26的生防功效，了解其定殖机理是关键。因此本项目以Z26与油茶为研究对象，采用荧光显微技术、De Nove测序、RT-PCR技术及基因敲除等技术手段，研究Z26在油茶根系的分布及运移规律，探究Z26诱导寄主先天免疫反应（PTI），明确Z26响应PTI的主要分泌系统，以期阐明Z26在油茶根部定殖的分子机理，为提高Z26的生防效果提供理论依据，同时对于生防细菌与植物互作的基础研究也具有重要意义。

利用生防细菌防控油茶病害是生物防控的关键。成功定殖是实现生防细菌稳定发挥功效的决定性因素之一。为了稳定生防细菌的功效，必须要明确生防细菌的定殖的机理。为此，本项目开展了内生拮抗细菌的筛选，内生拮抗细菌在油茶根际定殖情况，诱导的植物先天免疫反应及其对油茶根系基因表达水平影响等方面的研究。筛选了一株对油茶炭疽病、茶籽霉烂具有明显防效的内生细菌；明确了内生拮抗细菌在油茶植株内的定殖规律，发现内生拮抗细菌在油茶和拟南芥根部定殖存在差异；证明了内生细菌可引起油茶植株的先天免疫反应；研究了接种内生细菌后油茶根系转录组的变化。初步揭示了油茶内生细菌定殖的分子机理，为内生细菌与油茶的互作机制研究提供了基础，也为改善生防菌的定殖能力提供了理论依据。