Abstract:Phytophthora pathogens secrete large amounts of RxLR effectors to interfere with host plant cell physiology and function. Here, we identified 9 PiAvr3a-like genes in P. capsici by BLAST searching and demonstrated that this gene group was also widely distributed in P. sojae, suggesting their potential importance in virulence. We cloned 5 PiAvr3a-like genes from P. capsici, three of which exhibited high expressional levels at early infection stage, suggesting that they may play important roles in this stage. Among the 5 genes, transient expression of PcAvh128 in Nicotiana benthamiana could promote P. capsici infection whereas PcAvh132 could reduce the infection. None of them could suppress plant cell death that are induced by INF1 or effectors, and induce hypersensitivity reaction in N. benthamiana. These results together suggest P. capsici PiAvr3a-like effectors have divergent functions during infection and lay a fundament to study interactions of Phytophthora pathogens and their hosts.