Abstract：
The isochorismate synthase (ICS) proteins are essential regulators of salicylic acid (SA) synthesis, which has been reported to regulate resistance to biotic and abiotic stresses in plants. Clubroot caused by Plasmodiophora brassicae is a common disease that threatens the yield and quality of Oilseed rape (Brassica napus L.). Exogenous application of salicylic acid reduced the incidence of clubroot in oilseed rape. However, the potential importance of the ICS genes family in B. napus and its diploid progenitors has been unclear. Here, we identified 16, 9, and 10 ICS genes in the allotetraploid B. napus, diploid ancestor Brassica rapa and Brassica oleracea, respectively. These ICS genes were classified into three subfamilies (I-III), and member of the same subfamilies showed relatively conserved gene structures, motifs, and protein domains. Furthermore, many hormone-response and stress-related promoter cis-acting elements were observed in the BnaICS genes. Exogenous application of SA delayed the growth of clubroot galls, and the expression of BnaICS genes was significantly different compared to the control groups. Protein-protein interaction analysis identified 58 proteins involved in the regulation of ICS in response to P. brassicae in B. napus. These results provide new clues for understanding the resistance mechanism to P. brassicae.
摘要：
异分支酸合酶（ICS）蛋白是水杨酸（SA）合成的重要调节因子，据报道，它可以调节植物对生物和非生物胁迫的抗性。由油菜疟原虫引起的丛枝病是一种常见病，威胁着油菜的产量和品质。外源施用水杨酸降低了油菜根茎病的发生率。然而,ICS基因家族在欧洲油菜及其二倍体祖细胞中的潜在重要性尚不清楚.这里,我们在同种四倍体油菜中鉴定了16、9和10个ICS基因，二倍体祖先甘蓝型油菜和甘蓝，分别。这些ICS基因分为三个亚家族(I-III)，同样的亚家族成员表现出相对保守的基因结构，图案，和蛋白质结构域。此外，在BnaICS基因中观察到许多激素反应和应激相关的启动子顺式作用元件。外源施用SA延缓了根瘤菌的生长，BnaICS基因的表达与对照组相比有显著差异。蛋白质-蛋白质相互作用分析确定了58种蛋白质参与响应于甘蓝型油菜中的油菜油菜的ICS调节。这些结果为了解油菜的抗性机制提供了新的线索。
