Abstract: To explore the function of AUX/IAA family genes on leaves and shoot tips development in cabbage, and screen the key AUX/IAA genes associated with leaves and shoot tips development, this study took cabbage line ‘519’  as material and though transcriptome comparative analysis screened 2 AUX/IAA genes expressed significantly different in shoot and leaves tips during heading and rosette stages, named BoIAA2 and BoIAA19, respectively. The cDNA sequences of BoIAA2 and BoIAA19 gene were obtained by PCR. Their CDS  length was 519 bp and 585 bp, and encoded 172, 194 amino acids, respectively. Further sequences discovered that the comparability of BoIAA2 and BoIAA19 with BrIAA2 and BnIAA19 were 99%, which contained the typical AUX/IAA DomainⅠ, Ⅱ, Ⅲ and Ⅳ. The RT-PCR analysis showed that the relative expression levels of BoIAA2 and BoIAA19 genes during heading stage were higher than rosette stage both in leaves and shoot tips, which was completely consistent with expression trend of their binding protein genes BoTIR1 and BoARF8, suggesting that BoIAA2 and BoIAA19 might regulate auxin signal transduction by combining backward genes BoTIR1 with BoARF8, and participate in leaves and shoot tips development regulation in cabbage.

Key words: Brassica oleracea L. var. capitata L., AUX/IAA, gene cloning, expression analysis

摘要： 为了探究AUX/IAA家族基因在结球甘蓝叶片与茎尖发育过程中的功能，筛选出对甘蓝叶片与茎尖发育具重要影响的相关AUX/IAA基因。试验以结球甘蓝品系“519”为材料，通过对莲座期叶片与茎尖，结球期叶片与茎尖的转录组比较分析，筛选出在两个组织中均表达差异显著的2个AUX/IAA基因，分别为BoIAA2与BoIAA19。采用PCR技术分别获得基因BoIAA2与BoIAA19的编码序列，其CDS(coding sequence)全长分别为519 bp 、585 bp，编码172、194个氨基酸；进一步序列分析发现BoIAA2、BoIAA19分别与大白菜BrIAA2、油菜BnIAA19氨基酸同源相似性均达99%，且均具有AUX/IAA蛋白的DomainⅠ、Ⅱ、Ⅲ和Ⅳ特异性结构域。利用荧光定量PCR分析表明BoIAA2和BoIAA19在叶片、茎尖中的表达量均呈现出结球期高于莲座期的变化趋势,与转录组分析结果相符；对其结合蛋白基因BoTIR1和BoARF8进行表达分析，结果显示二者与BoIAA2、BoIAA19在叶片、茎尖中不同时期的表达量变化趋势一致；由此，推测BoIAA2和BoIAA19可能通过与BoTIR1和BoARF8的结合影响生长素信号转导，进而调控结球甘蓝叶片及茎尖的生长发育。

关键词: 结球甘蓝, AUX/IAA, 基因克隆, 表达分析