芥菜BjuBBX基因家族全基因组鉴定与分析

Genome-wide Identification and Analysis of BjuBBX Gene Family in Brassica juncea

BBX蛋白质是植物中广泛存在的锌指转录因子,参与种子萌发、下胚轴生长、开花、昼夜节律和逆境响应等发育过程,利用芥菜(Brassica juncea)基因组数据,通过TBTools等软件筛选鉴定出82个芥菜BjuBBX家族基因,可分为5个亚家族,具有较高的群体特异性。染色体分布和共线性分析表明,基因重复事件对芥菜基因组中BjuBBX基因的扩增至关重要,群类间的进化速率和氨基酸性质的变化很可能会导致其功能分化。顺式作用元件分析表明:BjuBBX家族成员的启动子大多富集了光信号、激素响应和胁迫应答等途径的顺式元件。同时,基于芥菜茎膨大、高温和干旱胁迫的转录组数据分析表明,GroupⅠ中BjuBBX基因在茎膨大过程中呈较高表达,且在不同阶段具有表达的时空特异性;BjuBBX8-3、BjuBBX11、BjuBBX24-4等基因的表达会积极响应高温和干旱胁迫,暗示其在逆境应答中具重要功能。这为进一步解析BjuBBX家族在芥菜中的生物学功能奠定基础,为芥菜等十字花科作物的生物育种提供了借鉴。

BBX proteins are a class of zinc-finger transcription factors in plants,which are mainly involved in plant processes such as seed germination,hypocotyl growth,flowering,circadian rhythm and stress response.Here,82 BjuBBX family genes were identified by screening the genomic data of Brassica juncea and software such as TBTools,and they could be classified into five groups,with high population specificity.Chromosome distribution and covariance analysis indicated that gene duplication events were crucial for the amplification of BjuBBX genes in the B.juncea genome.Their functional divergence probably resulted from the variations in evolutionary rates and amino acid properties among group classes.Meanwhile,cis-acting element analysis demonstrated that the promoters of BjuBBX genes were enriched in the cis-elements about light signaling,hormone response and stress response.Furthermore,based on the transcriptome data from stem expansion,high temperature and drought stress,BjuBBX genes in GroupⅠwere highly expressed during stem expansion and had spatial-temporal specificity at different stages.The expression of BjuBBX8-3,BjuBBX11,and BjuBBX24-4 in B.juncea responded positively to high temperature and drought stress,indicating that they probably played important roles in the environmental stress.The results lay the foundation for further elucidating the biological functions of the BjuBBX genes in B.juncea.It also can be used as a reference for the biological breeding of cruciferous crops.