Sun Wen Xiu, Jia Yong Jian, Feng Bao Zhen, O'Neill Nichole R, Zhu Xiao Ping, Xie Bing Yan, Zhang Xiu Guo
Department of Plant Pathology, Shandong Agricultural University, Tai'an 271018, China.
Genesis. 2009 Aug;47(8):535-44. doi: 10.1002/dvg.20530.
Phytophthora capsici causes serious diseases in numerous crop plants. Polygalacturonases (PGs) are cell wall-degrading enzymes that play an important role in pathogenesis in straminopilous pathogens. To understand PGs as they relate to the virulence of P. capsici, Pcipg2 was identified from a genomic library of a highly virulent P. capsici strain. Pcipg2 was strongly expressed during symptom development after the inoculation of pepper leaves with P. capsici. The wild protein (PCIPGII) was obtained from the expression of pcipg2 and found that increasing activity of PGs in PCIPGII-treated pepper leaves was consistent with increasing symptom development. Asp residues in active sites within pcipg2 affected PCIPGII activity or its virulence on pepper leaves. Results show that pcipg2 is an important gene among pcipg genes, and illustrate the benefit of analyzing mechanisms of pathogenicity during the period of host/parasite interaction.
辣椒疫霉在许多农作物上引发严重病害。多聚半乳糖醛酸酶（PGs）是细胞壁降解酶，在卵菌纲病原体的致病过程中发挥重要作用。为了解与辣椒疫霉毒力相关的PGs，从高毒力辣椒疫霉菌株的基因组文库中鉴定出Pcipg2。在用辣椒疫霉接种辣椒叶片后症状发展期间，Pcipg2强烈表达。野生型蛋白（PCIPGII）通过pcipg2的表达获得，并且发现经PCIPGII处理的辣椒叶片中PGs活性增加与症状发展加剧一致。pcipg2活性位点内的天冬氨酸残基影响PCIPGII活性或其对辣椒叶片的毒力。结果表明，pcipg2是pcipg基因中的一个重要基因，并说明了在宿主/寄生虫相互作用期间分析致病机制的益处。
