Agricultural Bio-Resources Research Institute, Fujian Academy of Agriculture Sciences, Fuzhou, China.
Key Laboratory of Integrated and Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
Pest Manag Sci. 2022 Nov;78(11):5002-5013. doi: 10.1002/ps.7123. Epub 2022 Aug 26.
Bacterial wilt (BW) caused by Ralstonia solanacearum (RS) is considered as one of the most destructive plant diseases. An avirulent strain of RS, FJAT1458, is a potential biocontrol agent of BW. In this study, the mechanism of FJAT1458 against BW was evaluated.
FJAT1458 was tagged with the red fluorescent protein gene, and the resulting strain was named as FJAT1458-RFP. When FJAT1458-RFP and FJAT91-GFP (a virulent strain of RS labelled with the green fluorescent protein gene), were co-inoculated in potted tomato plants, the colonization of FJAT91-GFP reached an almost undetectable level at 7 days post-inoculation (dpi) in the roots and at 9 dpi in rhizosphere soil. When they were co-inoculated in a hydroponic tomato growing system, numbers of the two strains were similar at 3 dpi in the root tissues; however, FJAT91-GFP was not detected at 9 dpi while FJAT1458-RFP maintained 1.77 × 10 CFU g . The inoculation of FJAT1458-RFP alone or combination with FJAT91-GFP significantly increased tomato root activity. Moreover, expression levels of the defense-related genes PR-1a, GLUA, and CHI3 in tomato roots were significantly up-regulated by FJAT1458-RFP and co-inoculation of FJAT1458-RFP and FJAT91-GFP at 5 dpi, compared to the control (water, CK) treatment. Noteworthy, expression levels of GLUA in the treatments of FJAT1458-RFP and FJAT1458-RFP + FJAT91-GFP were 12.22- and 12.05-fold higher than that in the CK at 5 dpi, respectively.
The results suggested that the avirulent strain FJAT1458-RFP could suppress colonization of the virulent strain in tomato roots, and induce tomato plant resistance against BW. © 2022 Society of Chemical Industry.
由青枯雷尔氏菌（Ralstonia solanacearum）引起的细菌性萎蔫病（BW）被认为是最具破坏性的植物病害之一。青枯雷尔氏菌的无毒菌株 FJAT1458 是 BW 的一种潜在生物防治剂。在本研究中，评估了 FJAT1458 对 BW 的作用机制。
FJAT1458 被标记上红色荧光蛋白基因，所得菌株命名为 FJAT1458-RFP。当 FJAT1458-RFP 与 FJAT91-GFP（一株用绿色荧光蛋白基因标记的青枯雷尔氏菌毒性菌株）共同接种盆栽番茄植株时，FJAT91-GFP 在根部接种后 7 天（dpi）几乎检测不到，在根际土壤中 9 dpi 时也检测不到。当它们共同接种在水培番茄生长系统中时，两种菌株在根部组织中的数量在 3 dpi 时相似；然而，在 9 dpi 时未检测到 FJAT91-GFP，而 FJAT1458-RFP 保持 1.77×10 CFU/g 。单独接种 FJAT1458-RFP 或与 FJAT91-GFP 共同接种均显著提高了番茄根活力。此外，与对照（水，CK）处理相比，FJAT1458-RFP 单独接种或与 FJAT1458-RFP 和 FJAT91-GFP 共同接种均可显著上调番茄根部防御相关基因 PR-1a、GLUA 和 CHI3 的表达水平在 5 dpi 时。值得注意的是，在 FJAT1458-RFP 和 FJAT1458-RFP+FJAT91-GFP 处理中，GLUA 的表达水平分别比 CK 高 12.22 倍和 12.05 倍。
结果表明，无毒菌株 FJAT1458-RFP 可抑制番茄根部病原菌的定植，并诱导番茄植株对 BW 的抗性。© 2022 化学工业协会。
