Hayano-Saito Yuriko, Hayashi Keiko
NARO Central Region Agricultural Research Center, Tsukuba, Japan.
Front Plant Sci. 2020 May 8;11:519. doi: 10.3389/fpls.2020.00519. eCollection 2020.
Disease resistance is affected by temperature. A rice gene, , is known to have conferred sustained resistance to (RSV) despite global warming. protects plants from growth stunting caused by RSV. The underlying resistance mechanism is unclear. Here, showed stable RSV resistance for 20 years in laboratory experiments. This gene encodes a protein distinct from well-studied plant disease-resistance proteins. It has a domain homologous to the histidine kinase/heat-shock protein 90-like ATPase superfamily. Rice has three paralogous genes including . The genes are expressed mainly in meristematic tissues. In the initial period after viral inoculation, RSV multiplication enhanced , whereas suppressed RSV multiplication. silencing inhibited plant growth regardless of viral infection, and silencing of the other paralogous gene that located closely to caused morphological abnormalities. The results suggested that the and its paralogs are related to plant development; especially, supports meristem growth, resulting in plant growth stabilizing. Growth stunting in the -silenced plants was more severe under repetitive heat stress, suggesting that contributed to the attenuation of heat damage in plant development. The symptoms of RSV infection (chlorosis, wilting, stunting, fewer tillers, and defective panicles) were similar to those of heat damage, suggesting that RSV multiplication induces heat-like stress in meristematic cells. Our findings suggest that the mechanism of meristem growth protection conferred by allows plants to withstand both heat stress and RSV multiplication. The suppression of RSV multiplication by the function in meristems results in durable resistance.
抗病性受温度影响。已知一个水稻基因,尽管全球气候变暖,它仍能赋予对水稻条纹病毒(RSV)的持续抗性。该基因可保护植物免受RSV引起的生长发育迟缓。其潜在的抗性机制尚不清楚。在此,该基因在实验室实验中对RSV表现出了20年的稳定抗性。该基因编码一种与已充分研究的植物抗病蛋白不同的蛋白质。它具有一个与组氨酸激酶/热休克蛋白90样ATP酶超家族同源的结构域。水稻有三个同源基因,包括该基因。这些基因主要在分生组织中表达。在病毒接种后的初期,RSV的增殖增强了该基因的表达,而该基因又抑制了RSV的增殖。该基因沉默会抑制植物生长,无论是否受到病毒感染,并且与该基因紧密相邻的另一个同源基因沉默会导致形态异常。结果表明,该基因及其同源基因与植物发育有关;特别是,该基因支持分生组织生长,从而使植物生长稳定。在反复热胁迫下,该基因沉默的植物生长发育迟缓更为严重,这表明该基因有助于减轻植物发育过程中的热损伤。RSV感染的症状(黄化、萎蔫、发育迟缓、分蘖减少和穗部缺陷)与热损伤症状相似,这表明RSV的增殖在分生细胞中诱导了类似热的胁迫。我们的研究结果表明,该基因赋予的分生组织生长保护机制使植物能够耐受热胁迫和RSV增殖。该基因在分生组织中的功能对RSV增殖的抑制作用导致了持久抗性。