Shopan Jannat, Mou Haipeng, Zhang Lili, Zhang Changtong, Ma Weiwei, Walsh John A, Hu Zhongyuan, Yang Jinghua, Zhang Mingfang
Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, 310058, China.
School of Life Science, University of Warwick, Wellesbourne, Warwick, CV35 9EF, UK.
Plant J. 2017 Jun;90(5):929-940. doi: 10.1111/tpj.13519. Epub 2017 Apr 4.
Recessive resistances to plant viruses in the Potyvirus genus have been found to be based on mutations in the plant eukaryotic translation initiation factors, eIF4E and eIF4G or their isoforms. Here we report that natural, monogenic recessive resistance to the Potyvirus Turnip mosaic virus (TuMV) has been found in a number of mustard (Brassica juncea) accessions. Bulked segregant analysis and sequencing of resistant and susceptible plant lines indicated the resistance is controlled by a single recessive gene, recessive TuMV resistance 03 (retr03), an allele of the eukaryotic translation initiation factor 2B-beta (eIF2Bβ). Silencing of eIF2Bβ in a TuMV-susceptible mustard plant line and expression of eIF2Bβ from a TuMV-susceptible line in a TuMV-resistant mustard plant line confirmed the new resistance mechanism. A functional copy of a specific allele of eIF2Bβ is required for efficient TuMV infection. eIF2Bβ represents a new class of virus resistance gene conferring resistance to any pathogen. eIF2B acts as a guanine nucleotide exchange factor (GEF) for its GTP-binding protein partner eIF2 via interaction with eIF2·GTP at an early step in translation initiation. Further genotyping indicated that a single non-synonymous substitution (A120G) in the N-terminal region of eIF2Bβ was responsible for the TuMV resistance. A reproducible marker has been developed, facilitating marker-assisted selection for TuMV resistance in B. juncea. Our findings provide a new target for seeking natural resistance to potyviruses and new opportunities for the control of potyviruses using genome editing techniques targeted on eIF2Bβ.
现已发现，植物对马铃薯Y病毒属病毒的隐性抗性基于植物真核翻译起始因子eIF4E和eIF4G或其亚型的突变。本文报道，在多个芥菜（Brassica juncea）种质中发现了对马铃薯Y病毒属芜菁花叶病毒（TuMV）的天然单基因隐性抗性。对抗性和感病植株系进行混合分组分析法和测序表明，该抗性由一个隐性基因控制，即隐性TuMV抗性03（retr03），它是真核翻译起始因子2B-β（eIF2Bβ）的一个等位基因。在一个对TuMV敏感的芥菜植株系中沉默eIF2Bβ，并在一个对TuMV抗性的芥菜植株系中表达来自对TuMV敏感系的eIF2Bβ，证实了这种新的抗性机制。高效的TuMV感染需要eIF2Bβ特定等位基因的功能拷贝。eIF2Bβ代表了一类新的赋予对任何病原体抗性的病毒抗性基因。在翻译起始的早期阶段，eIF2B通过与eIF2·GTP相互作用，作为其GTP结合蛋白伴侣eIF2的鸟嘌呤核苷酸交换因子（GEF）。进一步的基因分型表明，eIF2Bβ N端区域的一个单非同义替换（A120G）导致了对TuMV的抗性。已开发出一种可重复的标记，便于在芥菜中进行TuMV抗性的标记辅助选择。我们的研究结果为寻找对马铃薯Y病毒的天然抗性提供了新靶点，并为利用针对eIF2Bβ的基因组编辑技术控制马铃薯Y病毒提供了新机会。
