A single amino acid substitution in the SdhB protein of succinate dehydrogenase determines resistance to amicarthiazol in Xanthomonas oryzae pv. oryzae

作者：Zhang, Yu-Jun; Li, Jun; Zhao, Wei; Zhou, Ming-Guo^*

来源：Pest Management Science, 2010, 66(6): 627-633.

DOI：10.1002/ps.1919

• Xanthomonas oryzae pv. oryzae
• amicarthiazol resistance
• succinate dehydrogenase
• sdhB
• carboxamide fungicides

BACKGROUND: Xanthomonas oryzae pv. Oryzae Ishiyama, a causal agent of rice bacterial leaf blight, was found to be sensitive in vitro to the systemic fungicide amicarthiazol (2-amino-4-methylthiazole -5-carboxanilide), which is a potent inhibitor of succinate dehydrogenase (SDH, EC 1.3.99.1). This paper aimed to determine the molecular resistance mechanism of X. oryzae pv. oryzae to amicarthiazol.
RESULTS: UV-induced resistant mutants of X. oryzae pv. oryzae to amicarthiazol were isolated. The activity of SDH in wild-type X. oryzae pv. oryzae was strongly inhibited by amicarthiazol, while that in resistant mutants was insensitive, although their SDH activity was decreased compared with the wild-type sensitive strain without amicarthiazol. A mutation of Histidine(229) (CAC) to Tyrosine(229) (TAC) was identified in sdhB, which encoded the iron-sulfur protein subunit of SDH. The sdhB from the mutant was ligated into a cosmid, pUFRO34, to generate pUFR034RAX, which conferred resistance to amicarthiazol when transformed into the wild-type sensitive strain.
CONCLUSION: A mutation of His(229) (CAC) to Tyr(229) (TAC) in SdhB was responsible for determining amicarthiazol resistance.

• 出版日期2010-6
• 单位南京农业大学