文献类型： 外文期刊

作者： Wang, Meiling ¹ ; Geng, Lili ¹ ; Jiao, Siming ³ ; Wang, Kui ¹ ; Xu, Wenyue ¹ ; Shu, Changlong ¹ ; Zhang, Jie ¹ ;

作者机构： 1.Chinese Acad Agr Sci, Inst Plant Protect, State Key Lab Biol Plant Dis & Insect Pests, Beijing, Peoples R China

2.Shanxi Agr Univ, Coll Plant Protect, Shanxi Key Lab Integrated Pest Management Agr, Taigu, Shanxi, Peoples R China

3.Chinese Acad Sci, Inst Proc Engn, Natl Engn Res Ctr Biotechnol, Natl Key Lab Biochem Engn,Army Key Lab Biopharmace, Beijing, Peoples R China

关键词： Bacillus thuringiensis; Induced systemic resistance; Extracellular polysaccharide; Micro-associated molecular patterns; Biocontrol of Sclerotinia sclerotiorum

期刊名称：BIOLOGICAL CONTROL （ 影响因子：4.2； 五年影响因子：4.1 ）

ISSN： 1049-9644

年卷期： 2023 年 183 卷

页码：

收录情况： SCI

摘要： Bacillus thuringiensis is known as an entomopathogenic bacterium active against different agricultural pests. Recently, some novel functions have been explored, including plant growth-promoting activities. In our previous work, B. thuringiensis strains were found to effectively suppress Sclerotinia sclerotiorum by inducing systemic resistance (ISR) in Brassica campestris (L.). However, the mechanism by which exogenous signals from B. thuringiensis are perceived by plants is still not clear. Here, based on challenge-inoculation assays, we found that exopolysaccharides (EPSs) of B. thuringiensis strains could limit the spread of S. sclerotiorum by ISR in B. campestris. We purified and characterized the Bt 4F5 EPS, and the molecular weight was 66.2 kDa. The main monosaccharide units of Bt 4F5 EPS were determined to be mannose, GluA, glucose and galactose. Cellular defense response markers such as defense-related enzymes were induced after the 4F5 EPSs pretreatment in the leaves. Moreover, quantitative real-time PCR results indicated that the defense-related genes HEL and PDF1.2 were upregulated, suggesting an activation of the JA/ET signaling pathways by Bt 4F5 EPS. In addition, complete genome sequencing of the Bt 4F5 strain revealed twenty-one candidate genes involved in exopolysaccharide synthesis in chromosome. In summary, the EPSs of Bt strains play an important role in micro-associated mo-lecular pattern (MAMP) perception during the process of Bt-triggered systemic resistance.