Brachypodium distachyon line Bd3-1 resistance is elicited by the barley stripe mosaic virus triple gene block 1 movement protein
Brachypodium distachyon line Bd3-1 resistance is elicited by the barley stripe mosaic virus triple gene block 1 movement protein
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二穗短柄草系 Bd3-1 抗性是由大麦条纹花叶病毒三基因块 1 运动蛋白引起的
DOI：
10.1099/vir.0.045880-0
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发表时间：
2012-12-01
影响因子：
3.8
通讯作者：
Jackson, Andrew O.
中科院分区：
文献类型：
--
作者：
Lee, Mi Yeon;Yan, Lijie;Jackson, Andrew O.
大麦条纹花叶病毒北达科他州18（ND 18）、北京（BJ）、新疆（Xi）、TY型（TY）和CV 21株系不能侵染二穗短柄草Bd 3 -1自交系，而诺维奇（NW）株系对Bd 3 -1具有毒力。ND 18和NW基因组RNA抑制剂和RNA β突变体的分析表明，三重基因块1（TGB 1）运动蛋白的解旋酶基序内的两个氨基酸对其Bd 3 -1表型有重要影响。对ND 18的抗性与TGB 1第390位的精氨酸残基（R-390）和第392位的苏氨酸残基（T-392）相关，而毒性NW菌株在这两个位置都含有赖氨酸（K）。ND 18 TGB 1 R390 K（（ND）TGB 1（R390 K））和（ND）TGB 1（T392 K）单取代以及（ND）TGB 1（R390 K，T392 K）双突变导致Bd 3 -1的系统性感染。将（ND）TGB 1替换为（NW）TGB 1（（NW）TGB 1（K390 R）和（NW）TGB 1（K392 T））未能影响毒力，这意味着K-390和K-392相互补偿。与此相反，（NW）TGB 1（K390 R，K392 T）双突变体表现出有限的血管运动在Bd 3 -1，但发展了显着的坏死条纹，从次生叶脉蔓延。这种表型，结合在某些ND 18突变体中坏死点的出现，以及BJ菌株（（BJ）TGB 1（K390，T392））接种后Bd 3 -1植物的坏死和快速枯萎，表明Bd 3 -1 Bsr 1抗性是由TGB 1蛋白引起的，并表明它涉及过敏反应。
Barley stripe mosaic virus North Dakota 18 (ND18), Beijing (BJ), Xinjiang (Xi), Type (TY) and CV21 strains are unable to infect the Brachypodium distachyon Bd3-1 inbred line, which harbours a resistance gene designated Bsr1, but the Norwich (NW) strain is virulent on Bd3-1. Analysis of ND18 and NW genomic RNA reassortants and RNA beta mutants demonstrates that two amino acids within the helicase motif of the triple gene block 1 (TGB1) movement protein have major effects on their Bd3-1 phenotypes. Resistance to ND18 correlates with an arginine residue at TGB1 position 390 (R-390) and a threonine at position 392 (T-392), whereas the virulent NW strain contains lysines (K) at both positions. ND18 TGB1 R390K ((ND)TGB1(R390K)) and (ND)TGB1(T392K) single substitutions, and an (ND)TGB1(R390K,T392K) double mutation resulted in systemic infections of Bd3-1. Reciprocal (ND)TGB1 substitutions into (NW)TGB1 ((NW)TGB1(K390R) and (NW)TGB1(K392T)) failed to affect virulence, implying that K-390 and K-392 compensate for each other. In contrast, an (NW)TGB1(K390R,K392T) double mutant exhibited limited vascular movement in Bd3-1, but developed prominent necrotic streaks that spread from secondary leaf veins. This phenotype, combined with the appearance of necrotic spots in certain ND18 mutants, and necrosis and rapid wilting of Bd3-1 plants after BJ strain ((BJ)TGB1(K390,T392)) inoculations, show that Bd3-1 Bsr1 resistance is elicited by the TGB1 protein and suggest that it involves a hypersensitive response.