Genome-Wide Identification and Characterization of bZIP Transcription Factors inBrassica oleraceaunder Cold Stress

Abstract

Cabbages (Brassica oleracea L.) are an important vegetable crop around world, and cold temperature is among the most significant abiotic stresses causing agricultural losses, especially in cabbage crops. Plant bZIP transcription factors play diverse roles in biotic/abiotic stress responses. In this study, 119 putative BolbZIP transcription factors were identified using amino acid sequences from several bZIP domain consensus sequences. The BolbZIP members were classified into 63 categories based on amino acid sequence similarity and were also compared with BrbZIP and AtbZIP transcription factors. Based on this BolbZIP identification and classification, cold stress-responsive BolbZIP genes were screened in inbred lines, BN106 and BN107, using RNA sequencing data and qRT-PCR. The expression level of the 3 genes, Bol008071, Bol033132, and Bol042729, was significantly increased in BN107 under cold conditions and was unchanged in BN106. The upregulation of these genes in BN107, a cold-susceptible inbred line, suggests that they might be significant components in the cold response. Among three identified genes, Bol033132 has 97% sequence similarity to Bra020735, which was identified in a screen for cold-related genes in B. rapa and a protein containing N-rich regions in LCRs. The results obtained in this study provide valuable information for understanding the potential function of BolbZIP transcription factors in cold stress responses.

Exploring transcription factors reveals crucial members and regulatory networks involved in different abiotic stresses in Brassica napus L.

“…Compared with 87 [ 56 ], 132 [ 30 ] and 515 BnAP2/EREBPs [ 57 ] in B. napus that the references have reported, we identified 518 BnAP2/EREBPs, which include some novel members. Existing works also identified 136 BrbZIPs in B. rapa [ 31 ], 119 BobZIPs in B. oleracea [ 24 ] and 247 BnbZIPs in B. napus [ 8 ]. While the numbers of bZIPs for the three species identified by us are 126,127 and 252.…”

“…The RAV proteins further contain a B3 domain and the DREB proteins is rich in acidic amino acids in the C-terminal (CT). The bZIP proteins have a basic region that binds DNA and a leucine zipper dimerization motif [ 7 ], which can also be classified into several subfamilies according to their amino acid rich domain [ 24 ]. The MYB proteins typically go with a conserved MYB DNA-binding domain [ 10 , 12 ], which can be classified into four subfamilies depending on the number of adjacent repeats in the MYB domain [ 12 ].…”

“…The TAIR [ 28 ], BRAD [ 29 ] and PlantTFDB [ 27 ] have collected tens to hundreds of TFs for each family. Additionally, some works have reported that the AP2/EREBPs, bZIPs, MYBs, NACs and WRKYs play important roles during stimulus responsiveness [ 5 , 7 , 9 , 11 , 14 , 24 , 30 , 31 ]. For example, Du et al [ 30 ] identified 132 BnAP2/ERF genes by RNA-Seq of rapeseed leaves exposed to low temperature, and it was reported that the 132 BnAP2/ERFs involved several molecular pathways that may enhance cold resistance in plants.…”

“…For example, Du et al [ 30 ] identified 132 BnAP2/ERF genes by RNA-Seq of rapeseed leaves exposed to low temperature, and it was reported that the 132 BnAP2/ERFs involved several molecular pathways that may enhance cold resistance in plants. Hwang et al identified 136 BrbZIPs [ 31 ] in B. rapa and 119 BobZIPs [ 24 ] in B. oleracea , and cold responsiveness of these TFs were investigated by using RNA-Seq and qRT-PCR. Zhao et al [ 32 ] found that the expression of a bZIP gene, BnABF2 in B. napus , could be induced by drought and salt stresses.…”

Genomic Prediction and Association Mapping of Curd-Related Traits in Gene Bank Accessions of Cauliflower

“…The highest level of long-range LD is located on chromosome O4 in accessions of clusters 2 and 4 (data not shown). This chromosome harbors multiple paralogs of the BolbZIP gene family, which is involved into cold stress tolerance ( Hwang et al 2016 ). Although this trait was not evaluated in our field trials, we hypothesize that selection for cold tolerance in European varieties may explain the higher level of LD.…”