Identification and Functional Analysis of BrTIL Genes in Chinese Cabbage(Brassica rapa L.ssp.pekinensis)

Yang Cuicui; Cui Bing; Zhang Yihui; Li Jingjuan; Li Huayin; Liu Lifeng; Wang Fengde; Gao Jianwei

doi:10.14083/j.issn.1001-4942.2017.09.003

Abstract：The temperature induced lipocalin (TIL) protein plays an important role in the regulation of plant growth and development as well as the resistance to various stresses.In this study,four TIL genes were identified from the Chinese cabbage genome by bioinformatics method,and they were unevenly distributed on the Chinese cabbage chromosomes of A02,A03 and A10.Through the analysis of their gene and protein characteristics,it was found that the coding region of the four TIL genes were 414 ～750 bp,the predicted amino acid length were 137 ～249 aa,the molecular weight were 15.71 ～28.41 kD,and the pI value were 4.90 ～9.25.The multiple sequence alignment revealed that the DNA sequences of different BrTILs were highly similar,while their exon/intron structures were largely different.Furthermore,the expression pattern of BrTIL genes were analyzed using real-time quantitative PCR method (qRT-PCR).It was shown that different BrTILs had different expression patterns in different tissues of Chinese cabbage and the response patterns to temperature stress were also different,which might be related to different cis-elements in their promoter regions.The over-expression of BrTIL2 and BrTIL4 genes in Arabidopsis revealed that they both had similar functions in response to temperature and salt stress although their expression patterns had big differences.For example,over-expression of BrTIL2 and BrTIL4 genes could not improve the resistance to temperature stress,but could enhance the resistance to salt stress.This study not only provides a basis for the comprehensive understanding of the function of TIL genes in Chinese cabbage,but also provides important references for their applications in molecular breeding of Chinese cabbage.