Institute of Life Sciences, Jiangsu University, 301# Xuefu Road, Zhenjiang, 212013, People's Republic of China.
Plant Cell Rep. 2020 Jun;39(6):709-722. doi: 10.1007/s00299-020-02525-z. Epub 2020 Mar 5.
The BnaNPR1-like gene family was identified in B. napus, and it was revealed that repression of BnaNPR1 significantly reduces resistance toS. sclerotiorum, intensifies ROS accumulation, and changes the expression of genes associated with SA and JA/ET signaling in response to this pathogen. The NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) and related NPR1-like genes play an important role in regulating plant defense. Oilseed rape (Brassica napus L.) is an important oilseed crop; however, little is known about the B. napus (Bna) NPR1-like gene family. Here, a total of 19 BnaNPR1-like genes were identified in the B. napus genome, and then named according to their respective best match in Arabidopsis thaliana (At), which led to the determination of B. napus homologs of every AtNPR1-like gene. Analysis of important protein domains and functional motifs indicated the conservation and variation among these homologs. Phylogenetic analysis of these BnaNPR1-like proteins and their Arabidopsis homologs revealed six distinct sub-clades, consequently indicating that their name classification totally conformed to their phylogenetic relationships. Further, B. napus transcriptomic data showed that the expression of three BnaNPR1s was significantly down-regulated in response to infection with Sclerotinia sclerotiorum, the most important pathogen of this crop, whereas BnaNPR2/3/4/5/6s did not show the expression differences in general. Further, we generated B. napus BnaNPR1-RNAi lines to interpret the effect of the down-regulated expression of BnaNPR1s on resistance to S. sclerotiorum. The results showed that BnaNPR1-RNAi significantly decreased this resistance. Further experiments revealed that BnaNPR1-RNAi intensified ROS production and changed defense responses in the interaction of plants with this pathogen. These results indicated that S. sclerotiorum might use BnaNPR1 to regulate specific physiological processes of B. napus, such as ROS production and SA defense response, for the infection.
在油菜（ Brassica napus L.）中鉴定到了 BnaNPR1-like 基因家族，研究发现该基因家族的抑制会显著降低油菜对核盘菌（ Sclerotinia sclerotiorum ）的抗性，加剧 ROS 积累，并改变与 SA 和 JA/ET 信号转导相关的基因的表达，以应对这种病原体。非表达病原体相关基因 1（ NPR1）和相关的 NPR1-like 基因在调节植物防御中起着重要作用。油菜是一种重要的油料作物；然而，关于油菜的 BnaNPR1-like 基因家族知之甚少。在这里，在油菜基因组中总共鉴定到了 19 个 BnaNPR1-like 基因，然后根据它们在拟南芥（ Arabidopsis thaliana ）中的最佳匹配进行命名，从而确定了每个 AtNPR1-like 基因在油菜中的同源物。对重要蛋白质结构域和功能基序的分析表明，这些同源物之间存在保守性和变异性。对这些 BnaNPR1-like 蛋白及其拟南芥同源物的系统发育分析揭示了六个不同的亚群，这表明它们的命名分类完全符合它们的系统发育关系。此外，油菜转录组数据显示，在油菜感染核盘菌（ Sclerotinia sclerotiorum ）时，三个 BnaNPR1 的表达明显下调，核盘菌是该作物最重要的病原体，而 BnaNPR2/3/4/5/6s 通常没有表现出表达差异。进一步，我们生成了油菜 BnaNPR1-RNAi 系，以解释 BnaNPR1s 下调表达对核盘菌抗性的影响。结果表明，BnaNPR1-RNAi 显著降低了这种抗性。进一步的实验表明，BnaNPR1-RNAi 加剧了 ROS 的产生，并改变了植物与该病原体相互作用时的防御反应。这些结果表明，核盘菌可能利用 BnaNPR1 来调节油菜的特定生理过程，如 ROS 产生和 SA 防御反应，以进行侵染。
