Comparative Transcriptome Analysis Between Cold-Tolerant and Sensitive Brassica Oleracea L. in Response to Low Temperature Stress

Abstract

Background: Brassica oleracea L. occupies an important position in the annual production of vegetables. But during winter Brassica oleracea L. often suffers from low temperatures and even sub-zero temperatures. Through transcriptome analysis and identification, the pathways involved in cold tolerance of Brassica oleracea L. were analyzed and candidate genes related to cold tolerance of Brassica oleracea L. were identified.Results: Under low temperature stress, a large number of significantly different genes were found in Zhonggan1229 (ZG, low temperature tolerance) and Yingchun (YN, low temperature sensitive). There were 3902 significantly up-regulated genes and 5309 significantly down-regulated genes in ZG, and 4253 significantly up-regulated genes and 5938 significantly down-regulated genes in YN. Among them, 1844 different genes are the specific different genes in ZG and 6089 genes are the common different genes to response the low temperature stress. By annotating the specific different genes in ZG, 26 of the top 30 enriched GO terms belonged to biological processes, 4 terms belonged to molecular functions. By annotating the common different genes, 23 GO terms belonged to biological processes, 1 GO term belonged to molecular functions, and 6 GO terms belonged to cellular components. Circadian rhythms of plants and Plant hormone signal transduction were not only significantly enriched in the two analyzed genes, but also the effects of low temperature stress were most significant. Among the unique different genes in ZG, 154 genes were annotated into transcription factor families, and 79 genes were up-regulated and 75 genes were down-regulated, the encoding of MYB-related proteins was the largest group. Among the different genes shared by the two varieties, 516 genes were annotated into corresponding transcription factor families, 211 genes were up-regulated and 296 genes were down-regulated, however, there were 4 genes that were up-regulated in ZG but down-regulated in YN, and 5 genes that were down-regulated in ZG but up-regulated in YN, the largest group was the protein encoding ERF.Conclusions: The results identified important genes, pathways, and transcription factors that respond to low temperature stress, provided cold tolerance gene resources for the subsequent cold tolerance breeding research of Brassica oleracea L..