Chen Jheng-Yan, Sang Hyunkyu, Chilvers Martin I, Wu Chih-Hang, Chang Hao-Xun
Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan.
Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, Republic of Korea.
Front Plant Sci. 2024 Feb 9;15:1341181. doi: 10.3389/fpls.2024.1341181. eCollection 2024.
Rhizobacteria are capable of inducing defense responses via the expression of pathogenesis-related proteins (PR-proteins) such as chitinases, and many studies have validated the functions of plant chitinases in defense responses. Soybean () is an economically important crop worldwide, but the functional validation of soybean chitinase in defense responses remains limited. In this study, genome-wide characterization of soybean chitinases was conducted, and the defense contribution of three chitinases (GmChi01, GmChi02, or GmChi16) was validated in transgenic lines against the soil-borne pathogen . Compared to the Col-0 and empty vector controls, the transgenic lines with GmChi02 or GmChi16 exhibited fewer chlorosis symptoms and wilting. While GmChi02 and GmChi16 enhanced defense to , GmChi02 was the only one significantly induced by . The observation indicated that plant chitinases may be induced by different rhizobacteria for defense responses. The survey of 37 soybean chitinase gene expressions in response to six rhizobacteria observed diverse inducibility, where only 10 genes were significantly upregulated by at least one rhizobacterium and 9 genes did not respond to any of the rhizobacteria. Motif analysis on soybean promoters further identified not only consensus but also rhizobacterium-specific transcription factor-binding sites for the inducible chitinase genes. Collectively, these results confirmed the involvement of GmChi02 and GmChi16 in defense enhancement and highlighted the diverse inducibility of 37 soybean chitinases encountering and six rhizobacteria.
根际细菌能够通过表达几丁质酶等病程相关蛋白（PR 蛋白）来诱导防御反应，许多研究已经证实了植物几丁质酶在防御反应中的功能。大豆是全球一种重要的经济作物，但大豆几丁质酶在防御反应中的功能验证仍然有限。在本研究中，对大豆几丁质酶进行了全基因组表征，并在针对土传病原菌的转基因系中验证了三种几丁质酶（GmChi01、GmChi02 或 GmChi16）的防御作用。与野生型 Col-0 和空载体对照相比，含有 GmChi02 或 GmChi16 的转基因系表现出较少的黄化症状和萎蔫。虽然 GmChi02 和 GmChi16 增强了对[病原菌名称未给出]的防御，但 GmChi02 是唯一一种受到[诱导物名称未给出]显著诱导的酶。该观察结果表明，植物几丁质酶可能由不同的根际细菌诱导以产生防御反应。对 37 个大豆几丁质酶基因响应六种根际细菌的表达情况进行的调查发现，诱导性各不相同，其中只有 10 个基因至少被一种根际细菌显著上调，9 个基因对任何一种根际细菌都没有反应。对大豆启动子的基序分析进一步确定了可诱导几丁质酶基因的共有基序以及根际细菌特异性转录因子结合位点。总的来说，这些结果证实了 GmChi02 和 GmChi16 在增强防御中的作用，并突出了 37 个大豆几丁质酶在面对[病原菌名称未给出]和六种根际细菌时的不同诱导性。
