School of Plant Biology, Faculty of Science, The University of Western Australia, Crawley, Western Australia, Australia.
PLoS One. 2013 Jun 11;8(6):e65205. doi: 10.1371/journal.pone.0065205. Print 2013.
Sclerotinia rot caused by Sclerotinia sclerotiorum is one of the most serious diseases of oilseed rape. To understand the resistance mechanisms in the Brassica napus to S. sclerotiorum, comparative disease progression, histological and proteomic studies were conducted of two B. napus genotypes (resistant cv. Charlton, susceptible cv. RQ001-02M2). At 72 and 96 h post inoculation (hpi), lesion size on cotyledons was significantly (P≤0.001) smaller in the resistant Charlton. Anatomical investigations revealed impeded fungal growth (at 24 hpi and onwards) and hyphal disintegration only on resistant Charlton. Temporal changes (12, 24, 48 and 72 hpi) in protein profile showed certain enzymes up-regulated only in resistant Charlton, such as those related to primary metabolic pathways, antioxidant defence, ethylene biosynthesis, pathogenesis related proteins, protein synthesis and protein folding, play a role in mediating defence responses against S. sclerotiorum. Similarly a eukaryotic translation initiation factor 5A enzyme with increased abundance in susceptible RQ001-02M2 and decreased levels in resistant Charlton has a role in increased susceptibility to this pathogen. This is the first time that the expression of these enzymes has been shown to be associated with mediating the defence response against S. sclerotinia in cotyledon tissue of a resistant cultivar of B. napus at a proteomics level. This study not only provides important new insights into the resistance mechanisms within B. napus against S. sclerotiorum, but opens the way for novel engineering of new B. napus varieties that over-express these key enzymes as a strategy to enhance resistance and better manage this devastating pathogen.
由核盘菌引起的菌核病是油菜的最严重病害之一。为了了解油菜对核盘菌的抗性机制，对两种油菜基因型（抗性品种 Charlton 和感病品种 RQ001-02M2）进行了比较病害进展、组织学和蛋白质组学研究。在接种后 72 和 96 小时（hpi），子叶上的病斑大小在抗性 Charlton 中显著较小（P≤0.001）。解剖学研究表明，仅在抗性 Charlton 中，真菌生长受阻（在 24 hpi 及以后）和菌丝解体。蛋白谱的时间变化（12、24、48 和 72 hpi）表明，某些仅在抗性 Charlton 中上调的酶，如与初级代谢途径、抗氧化防御、乙烯生物合成、病程相关蛋白、蛋白质合成和蛋白质折叠相关的酶，在介导对核盘菌的防御反应中起作用。同样，在感病 RQ001-02M2 中丰度增加而在抗性 Charlton 中水平降低的真核翻译起始因子 5A 酶在增加对该病原体的易感性方面也具有作用。这是首次在蛋白质组学水平上表明，这些酶的表达与介导油菜对核盘菌的防御反应有关。这项研究不仅为油菜对核盘菌的抗性机制提供了重要的新见解，而且为新型油菜品种的工程设计开辟了道路，这些品种可以过表达这些关键酶，作为增强抗性和更好管理这种破坏性病原体的策略。
