Okada Kaori, Xu Wenjing, Mishina Kohei, Oono Youko, Kato Tsuneo, Namai Kiyoshi, Komatsuda Takao
Tochigi Prefectural Agricultural Experiment Station, Utsunomiya, Tochigi, Japan.
Crop Research Institute, Shandong Academy of Agricultural Sciences (SAAS), Ji'nan, Shandong, China.
Front Plant Sci. 2023 Mar 10;14:1149752. doi: 10.3389/fpls.2023.1149752. eCollection 2023.
Infection by the (JSBWMV) can lead to substantial losses in the grain yield of barley and wheat crops. While genetically based resistance to this virus has been documented, its mechanistic basis remains obscure. In this study, the deployment of a quantitative PCR assay showed that the resistance acts directly against the virus rather than by inhibiting the colonization of the roots by the virus' fungal vector . In the susceptible barley cultivar (cv.) Tochinoibuki, the JSBWMV titre was maintained at a high level in the roots during the period December-April, and the virus was translocated from the root to the leaf from January onwards. In contrast, in the roots of both cv. Sukai Golden and cv. Haruna Nijo, the titre was retained at a low level, and translocation of the virus to the shoot was strongly suppressed throughout the host's entire life cycle. The roots of wild barley ( ssp. ) accession H602 responded in the early stages of infection similarly to those of the resistant cultivated forms, but the host was unable to suppress the translocation of the virus to the shoot from March onwards. The virus titre in the root was presumed to have been restricted by the action of the gene product of (on chromosome 2H), while the stochastic nature of the infection was suppressed by the action of that of (on chromosome 3H), a gene harbored by cv. Sukai Golden but not by either cv. Haruna Nijo or accession H602.
感染大麦和小麦花叶病毒（JSBWMV）会导致大麦和小麦作物的谷物产量大幅损失。虽然已经有关于这种病毒的基因抗性的记录，但其机制基础仍然不明。在本研究中，定量PCR检测的应用表明，抗性直接作用于病毒，而非通过抑制病毒的真菌传播介体对根部的定殖来发挥作用。在感病的大麦品种丰之吹雪（cv.Tochinoibuki）中，12月至4月期间根部的JSBWMV滴度维持在较高水平，并且从1月起病毒从根部向叶片转移。相比之下，在品种菅井黄金（cv.Sukai Golden）和春名二号（cv.Haruna Nijo）的根部，滴度保持在较低水平，并且在寄主的整个生命周期中病毒向地上部的转移都受到强烈抑制。野生大麦（Hordeum vulgare ssp. spontaneum）材料H602的根部在感染早期的反应与抗性栽培品种相似，但从3月起寄主无法抑制病毒向地上部的转移。根部的病毒滴度推测受到2H染色体上HvRrs1基因产物的作用限制，而感染的随机性受到菅井黄金品种所具有但春名二号品种或材料H602均不具有的3H染色体上HvRrs2基因作用的抑制。
