Natural variation in ZmFBL41 confers banded leaf and sheath blight resistance in maize

First author: Ning Li; Affiliations: Shandong Agricultural University (山东农业大学): Taian, China

Corresponding author: Zhaohui Chu 

Rhizoctonia solani is a widely distributed phytopathogen that causes banded leaf and sheath blight in maize and sheath blight in rice. Here, we identified an F-box protein (ZmFBL41) that confers resistance to banded leaf and sheath blight through a genome-wide association study in maize. Rice overexpressing ZmFBL41 showed elevated susceptibility to R. solani. Two amino acid substitutions in this allele prevent its interaction with ZmCAD, which encodes the final enzyme in the monolignol biosynthetic pathway, resulting in the inhibition of ZmCAD degradation and, consequently, the accumulation of lignin and restriction of lesion expansion. Knocking out the ZmCAD-homologous gene OsCAD8B in rice enhanced susceptibility to R. solani. The results reveal a susceptibility mechanism in which R. solani targets the host proteasome to modify the secondary metabolism of the plant cell wall for its invasion. More importantly, it provides an opportunity to generate R. solani–resistant varieties of different plant species.

立枯丝核菌（Rhizoctonia solani）是一种分布范围较广的病原菌，会导致玉米叶片及叶鞘纹枯病和水稻叶鞘纹枯病。本文中，作者通过全基因组关联分析鉴定到了一个F-box蛋白ZmFBL41赋予玉米对叶片及叶鞘纹枯病的抗性。水稻中过表达ZmFBL41基因会导致其对立枯丝核菌的易感性增强。ZmFBL41蛋白上两个氨基酸的替换会阻止其与ZmCAD蛋白的相互作用，从而抑制ZmCAD的降解，而ZmCAD蛋白编码的酶作用于单木酚生物合成途径中最后一步反应，因此抑制木质素的积累以及病变扩张的限制。敲除水稻中ZmCAD的同源基因OsCAD8B能够增强水稻对于立枯丝核菌的易感性。本文的结果揭示了一个植物感病的分子机制，即立枯丝核菌通过靶向宿主蛋白酶体改变植物细胞壁的次生代谢，从而有利于其侵入植物细胞。更重要的是，本文的研究结果为不同植物培育立枯丝核菌抗性品种提供了可能。

通讯：储昭辉 (http://agronomy.sdau.edu.cn/s/37/t/1751/c8/6e/info51310.htm)

个人简介：1995-2006年，华中农业大学，本硕博；2006-2008年，英国The Sainsbury Laboratory，博士后。

研究方向：植物-微生物相互作用：1）细菌性病害与水稻的互作；2）真菌性病害与玉米和水稻的互作；3）马铃薯晚疫病与茄科的互作。

doi: https://doi.org/10.1038/s41588-019-0503-y

Journal: Nature Genetics

Published date: September 30, 2019