Cytochrome B5 (CB5) family proteins play an important role in various oxidation/reduction reactions in cells as the electron donor and are involved in a variety of biotic and abiotic stress processes. However, the function of the CB5s in Brassica rapa is still unclear. In this study, we carried out genome-wide identification, characterization, and expression analysis of BrCB5s in different tissues under adversities and stresses. It was identified that fifteen BrCB5s were distributed on different chromosomes, which were classified into seven groups (A-G) according to its phylogenetic relationship. Phylogenetic analysis of the CB5 protein sequences from six species showed that the BrCB5s conduct a close evolutionary process with the CB5s of Arabidopsis thaliana and far from those of Oryza sativa. Protein interaction analysis showed that 40 interaction patterns were predicted including two Sucrose Transporter 4 subfamily proteins (SUT 4) and Fatty Acid Hydroxylase 2 protein (FAH 2) can interact with most members of BrCB5s. The expression profile analysis indicated that BrCB5s were differentially expressed in different tissues, and the transcript abundances were significantly different under various abiotic stresses and plant hormone treatments. Our study provides a basis for a better understanding of the characteristics and biological functions of the CB5 family genes in Chinese cabbage during plant development, especially in plant responses to multiple stresses.

中文翻译：

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大白菜（Brassica rapa L. ssp。Pekinensis）细胞色素B5蛋白家族的全基因组鉴定和分析

细胞色素B5（CB5）家族蛋白在细胞中作为电子供体的各种氧化/还原反应中发挥重要作用，并参与多种生物和非生物胁迫过程。但是，CB5s在芸苔中的功能仍不清楚。在这项研究中，我们在逆境和压力下对不同组织中的BrCB5s进行了全基因组范围的鉴定，表征和表达分析。鉴定出十五种BrCB5它们分布在不同的染色体上，根据其系统进化关系分为七个组。从六个物种的CB5蛋白序列的系统发育分析表明，BrCB5s与拟南芥的CB5s紧密进化，而与Oryza sativa的CB5s远非如此。蛋白质相互作用分析表明，预测了40种相互作用模式，其中包括两个蔗糖转运蛋白4亚家族蛋白（SUT 4）和脂肪酸羟化酶2蛋白（FAH 2）可以与大多数BrCB5s相互作用。表达谱分析表明BrCB5s在不同的非生物胁迫和植物激素处理下，转录本的丰度差异显着。我们的研究为更好地了解白菜中CB5家族基因在植物发育过程中的特性和生物学功能提供了基础，特别是在植物对多种胁迫的反应中。