State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, People's Republic of China.
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China.
Annu Rev Phytopathol. 2018 Aug 25;56:311-338. doi: 10.1146/annurev-phyto-080417-050052. Epub 2018 Jun 29.
Oxalic acid production in Sclerotinia sclerotiorum has long been associated with virulence. Research involving UV-induced, genetically undefined mutants that concomitantly lost oxalate accumulation, sclerotial formation, and pathogenicity supported the conclusion that oxalate is an essential pathogenicity determinant of S. sclerotiorum. However, recent investigations showed that genetically defined mutants that lost oxalic acid production but accumulated fumaric acid could cause disease on many plants and substantiated the conclusion that acidic pH, not oxalic acid per se, is the necessary condition for disease development. Critical evaluation of available evidence showed that the UV-induced mutants harbored previously unrecognized confounding genetic defects in saprophytic growth and pH responsiveness, warranting reevaluation of the conclusions about virulence based on the UV-induced mutants. Furthermore, analyses of the evidence suggested a hypothesis for the existence of an unrecognized regulator responsive to acidic pH. Identifying the unknown pH regulator would offer a new avenue for investigating pH sensing/regulation in S. sclerotiorum and novel targets for intervention in disease control strategies.
草酸的产生与致病力在核盘菌中长期相关。涉及紫外线诱导、遗传上未定义的突变体的研究同时丧失了草酸盐的积累、菌核的形成和致病性，支持了草酸是核盘菌致病性决定因素的结论。然而，最近的研究表明，遗传上定义的丧失草酸生产但积累延胡索酸的突变体可以在许多植物上引起疾病，并证实了酸性 pH 值，而不是草酸本身，是疾病发展的必要条件。对现有证据的批判性评估表明，紫外线诱导的突变体在腐生生长和 pH 响应方面存在以前未被认识到的混杂遗传缺陷，有必要重新评估基于紫外线诱导突变体的关于毒力的结论。此外，对证据的分析提出了一个假设，即存在一个对酸性 pH 有反应的未知调节剂。鉴定未知的 pH 调节剂将为研究核盘菌的 pH 感应/调节提供新途径，并为疾病控制策略中的干预提供新的靶标。
