In:
Journal of General Virology, Microbiology Society, Vol. 93, No. 12 ( 2012-12-01), p. 2729-2739
Abstract:
Barley stripe mosaic virus North Dakota 18 (ND18), Beijing (BJ), Xinjiang (XJ), 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 RNAβ 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.
Type of Medium:
Online Resource
ISSN:
0022-1317
,
1465-2099
DOI:
10.1099/vir.0.045880-0
Language:
English
Publisher:
Microbiology Society
Publication Date:
2012
detail.hit.zdb_id:
2007065-2
SSG:
12
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