College of Life Sciences, Fujian Agricultural and Forestry University, Fuzhou, China.
Key Laboratory of Crop Physiology and Molecular Ecology, Fujian Agricultural and Forestry University, Fuzhou, China.
J Exp Bot. 2021 Oct 26;72(20):7247-7263. doi: 10.1093/jxb/erab338.
Root-pathogen interactions influence premature senescence in rice, however, few studies have addressed the underlying mechanism. In this study, when premature senescence significantly occurred in the osvha-a1 mutant (loss of tonoplast H+-ATPase activity), the relative abundance of rhizospheric bacterial communities was similar between the mutant and its wild type, while the fungi in the rhizosphere of the osvha-a1 mutant significantly differed from the wild type. Furthermore, one key fungal strain in the rhizospheric soil of the osvha-a1 mutant, Gibberella intermedia, increased substantially during the late growing phase, resulting in severe accumulation of reactive oxygen species (ROS). By contrast, the wild type showed much lower levels of ROS when infected by G. intermedia. Using high performance liquid chromatography, sugars in root exudates were identified to be different between osvha-a1 mutant and the wild type. G. intermedia could use mannose and rhamnose in root exudates from the mutant more efficiently than any other sugar. Finally, antagonistic bacteria could be employed for limiting the proliferation of G. intermedia in the rhizosphere, thereby alleviating the early senescent phenotypes of the osvha-a1 mutant, and improving grain yield.
根-病原菌互作影响水稻早衰，然而，很少有研究涉及潜在的机制。在这项研究中，当 osvha-a1 突变体（液泡膜 H+-ATPase 活性丧失）中明显发生早衰时，突变体与其野生型之间的根际细菌群落的相对丰度相似，而 osvha-a1 突变体根际中的真菌则与野生型明显不同。此外，osvha-a1 突变体根际土壤中的一个关键真菌菌株，藤仓赤霉，在生长后期大量增加，导致活性氧（ROS）严重积累。相比之下，当野生型被 G. intermedia 感染时，ROS 水平要低得多。通过高效液相色谱法，鉴定出根分泌物中的糖在 osvha-a1 突变体和野生型之间存在差异。藤仓赤霉可以更有效地利用突变体根分泌物中的甘露糖和鼠李糖，而不是任何其他糖。最后，拮抗菌可以用来限制根际中 G. intermedia 的增殖，从而缓解 osvha-a1 突变体的早期衰老表型，并提高谷物产量。
