Genome- and Transcriptome-Wide Characterization of bZIP Gene Family Identifies Potential Members Involved in Abiotic Stress Response and Anthocyanin Biosynthesis in Radish (Raphanus sativus L.)

Abstract

Basic leucine zipper (bZIP) transcription factors play crucial roles in various abiotic stress responses as well as anthocyanin accumulation. Anthocyanins are most abundant in colorful skin radish, which exhibit strong antioxidant activity that offers benefits for human health. Here, a total of 135 bZIP-encoding genes were identified from radish genome. Synteny analysis showed that 104 radish and 63 Arabidopsis bZIP genes were orthologous. Transcriptome analysis revealed that 10 RsbZIP genes exhibited high-expression levels in radish taproot (RPKM>10). Specifically, RsbZIP010 exhibited down-regulated expression under Cd, Cr and Pb stresses, whereas RsbZIP031 and RsbZIP059 showed significant down-regulation under heat and salt stresses, respectively. RT-qPCR analysis indicated that RsbZIP011 and RsbZIP102 were significantly up-regulated in the tissues of radish with high anthocyanin contents. Furthermore, the promoter sequences of 39 anthocyanin-related genes were found to contain G-box or ACE-box elements that could be recognized by bZIP family members. Taken together, several RsbZIPs might be served as critical regulators in radish taproot under Cd, Cr, Pb, heat and salt stresses. RsbZIP011 and RsbZIP102 were the potential participants in anthocyanin biosynthesis pathway of radish. These results facilitate further investigation on functional characterization of bZIP genes in response to abiotic stress and anthocyanin biosynthesis in radish.

Genome-wide identification, phylogeny and expression analysis of the bZIP gene family in Alfalfa (Medicago sativa)

“…In the phylogenetic tree, MsbZIPs were predicted and analyzed by the optimized model, LG + G, after which they were divided into 11 sub-families. Similar results were reported in Arabidopsis [3]; Ustilaginoidea virens [38], Wild sweet potato (Ipomoea trifid) [39], Radish (Raphanus sativus L.) [40] and Carthamus tinctorius [41]. Each subfamily exhibited similar motifs and gene structures, corresponding to the findings reported in Arabidopsis, maize and alfalfa.…”

Mining and evolution analysis of lateral organ boundaries domain (LBD) genes in Chinese white pear (Pyrus bretschneideri)

“…Synteny analysis indicated that WGD event/segmental duplication played a leading role in the expansion of the PbrLBD gene family. However, our results of mean Ks and 4DTv values of PbrLBD paralogs showed that the PbrLBD gene family had undergone only one recent WGD/segmental duplication event (30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45) [20]. It is interesting to note that five duplicated gene pairs (PbrBD60/PbrBD59, PbrBD14/PbrBD42, PbrBD26/ PbrBD6, PbrBD57/PbrBD33 and PbrBD13/PbrBD41) exhibited relatively low mean Ks values, ranging from 0.008 to 0.14, suggesting that a more recent gene duplication event occurred in the evolution process of the PbrLBD gene family.…”

“…In pear, anthocyanin concentration determines fruit quality and color. However, anthocyanin accumulation is influenced by many environmental conditions, such as temperature, light and drought [42]. Numerous studies have indicated that LBD genes play important roles in anthocyanin biosynthesis processes.…”

Regulation Mechanisms of Plant Basic Leucine Zippers to Various Abiotic Stresses

“…In addition, ABA can induce the expression of Artemisia annua AabZIP1 to activate the expression of downstream gene ADS and CYP71AV1, thereby regulating the biosynthesis of artemisinin (Zhang F. Y. et al, 2015). Fan et al (2019) showed that the expression of RsbZIP011 and RsbZIP102 were significantly upregulated in radish tissue with higher anthocyanin content under heat and salt stress. So far, the bZIPs that involve in flavonoid synthesis varies from plant species and their target genes (coding for different enzymes in flavonoid metabolism).…”