BBX是一类重要的锌指蛋白转录因子家族，包含1~2个高度保守位于蛋白质序列N端的BBX结构域，在调控植物的生长发育和响应环境胁迫中发挥着重要作用。利用生物信息学分析手段，在白菜型油菜中鉴定出59个BrBBX家族成员，对它们的染色体定位、基因结构、蛋白保守结构域，以及BrBBX46和BrBBX53基因的启动子进行了分析，并用qRT-PCR技术鉴定了BrBBX46和BrBBX53基因在模拟干旱和盐胁迫下的表达水平。结果显示，59个BrBBXs不均匀地分布于白菜型油菜基因组的10条染色体。通过对系统进化、基因结构、蛋白保守 结构域的分析，59个BrBBXs被分为5个亚族，每个亚族的基因结构、蛋白结构域和保守基序均相对保守，同一亚族的成员具有相似的基因结构和保守结构域。对启动子的分析结果显示，BrBBX46和BrBBX53基因的启动子中均含有大量的胁迫相关响应元件，尤其是干旱胁迫响应元件，二者均有14个；在40% PEG和120 mmol/L NaCl处理下，二者的表达水平均显著上升，说明BrBBX46和BrBBX53基因能够响应干旱和盐胁迫的诱导，可能在干旱和盐胁迫下发挥着重要功能。以上结果为进一步了解和利用BrBBX家族成员改良白菜型油菜耐旱耐盐新品种提供了良好的基因资源。

BBX is an important family of zinc finger protein transcription factors, containing one to two highly conserved BBX domains located at the N terminus of the protein sequence. It plays an important role in regulating plant growth and development and responding to environmental stress. In this study, 59 BrBBX family members were identified in B. rapa by bioinformatics analysis,and their chromosome location, gene structure, protein conserved domain, and promoters of BrBBX46 and BrBBX53 genes were analyzed. The expression levels of BrBBX46 and BrBBX53 were determined by qRT-PCR under simulated drought and salt stress. The result showed that 59 BrBBXs were unevenly distributed on 10 chromosomes of the B. rapa genome. Based on the analysis of phylogenetic evolution, gene structure and protein conserved domains, 59 BrBBXs were divided into five subfamilies. The gene structure, protein domain and conserved motifs of each subfamily were relatively conserved, and members of the same subfamily had similar gene structure and conserved domains. The results of promoter analysis showed that the promoters of BrBBX46 and BrBBX53 contained a large number of stress-related response elements， especially drought stress response elements, and there were 14 drought stress response elements in BrBBX46 and BrBBX53, respectively. The expression levels of BrBBX46 and BrBBX53 were significantly increased under the treatment of 40% PEG and 120 mM NaCl, indicating that BrBBX46 and BrBBX53 can respond to the induction of drought and salt stress and may play important functions under drought and salt stress. These results provide good gene resources for further understanding of BrBBX family and using BrBBX family members to improve the drought and salt tolerant new varieties of B. rapa.

S565.4

四川省财政自主创新专项(2022ZZCX028)。