Diversification and evolution of the avirulence gene AVR-Pita1 in field isolates of Magnaporthe oryzae

作者：Dai, Yuntao; Jia, Yulin^*; Correll, James; Wang, Xueyan; Wang, Yanli

来源：Fungal Genetics and Biology, 2010, 47(12): 973-980.

DOI：10.1016/j.fgb.2010.08.003

• Magnaporthe oryzae
• Effector
• Metalloprotease
• Evolution
• Signal recognition

Rice blast disease is the single most destructive plant disease that threatens stable rice production worldwide Race-specific resistance to the rice blast pathogen has not been durable and the mechanism by which the resistance is overcome remains largely unknown Here we report the molecular mechanisms of diversification and the instability of the avirulence gene AVR Pita1 in field strains of Magnaporthe oryzae interacting with the host resistance gene Pi to and triggering race-specific resistance Two-base pair insertions resulting in frame-shift mutations and partial and complete deletions of AVR-Pita1 were identified in virulent isolates Moreover a total of 38 AVR-Pita1 haplotypes encoding 27 AVR-Pita1 variants were identified among 151 avirulent isolates Most DNA sequence variation was found to occur in the exon region resulting in amino acid substitution These findings demonstrate that AVR-Pita1 is under positive selection and mutations of AVR-Pita1 are responsible for defeating race-specific resistance in nature Published by Elsevier Inc

• 出版日期2010-12
• 单位浙江省农业科学院; 中国计量大学