青花菜乙烯反应传感蛋白基因BoERS的克隆与表达分析

乙烯反应传感蛋白在乙烯信号转导中起着重要作用,可作为负调控因子使下游的CTR1失活,并激活之后的一系列反应。为明确青花菜ERS基因的序列特征和表达特点,本研究以青花菜为试验材料,在克隆乙烯反应传感蛋白基因BoERS的基础上进行表达分析,以明确其在核盘菌和根肿菌侵染下的表达模式。结果表明,BoERS的基因组DNA全长为1 928 bp,含有1个长度为68 bp的内含子;编码区全长为 1 860 bp,编码619个氨基酸,编码蛋白有4个跨膜结构域、1个GAF结构域和1个HisKA结构域。序列比对结果表明,BoERS与芸薹属ERS序列的差异最小,在系统发育树上处于同一分支,但与萝卜属、盐芥属和拟南芥属植物ERS序列的差异较大,在系统发育树上处于不同的分支。实时荧光定量PCR结果表明,BoERS的表达受核盘菌的诱导,36 h时表达量最大,为对照的3.53倍,但BoERS的表达不受根肿菌的诱导。本研究结果为进一步开展BoERS基因功能鉴定和应用研究奠定了理论基础。

Isolation and Expression Analysis of Broccoli Ethylene Response Sensor Gene BoERS

Ethylene response sensor protein plays an important role in ethylene signal transduction. It acts as a negative regulator which inactivates downstream component CTR1, and triggers a series of reactions succedently. To investigate sequence chavacterristics and expression features of the broccoli ERS gene, our aim is to isolate an ethylene response sensor gene in broccoli and to obtain its expression pattern induced by Sclerotinia sclerotiorum and Plasmodiophora brassicae, thus provide a foundation for its role in disease resistance response. Results indicated that the genomic DNA of BoERS was 1 928 bp in length, containing a 68 bp intron. The full coding sequence was 1 860 bp encoding 619 amino acids, and the deduced protein contained four transmembrane domains, one GAF domain and one HisKA domain. Sequence comparison revealed BoERS showed little difference form ERSs of other Brassica plants, and they were grouped into the same clade, however, larger differences were observed between BoERS and ERSs from Raphanus, Thellungiella and Arabidopsis plants, and they clustered in different clades. Quantitative real-time PCR showed that the expression of BoERS was induced by S. sclerotiorum, and the highest expression level was observed at 36 h with a 3.53 fold increase. Isolation and expression analysis of BoERS laid a basis for gene function identification as well as its application in the future.