Anthocyanin Synthesis and the Expression Patterns of bHLH Transcription Factor Family during Development of the Chinese Jujube Fruit (Ziziphus jujuba Mill.)

Abstract

The basic helix–loop–helix (bHLH) family is an important transcription factor for eukaryotes and is involved in a wide range of biological activities. Among these, bHLH can interaction with WD repeat (WD40 or WDR) and V-myb avian myeloblastosis viral oncogene homolog (MYB) form a ternary complex to promote the efficient synthesis of anthocyanins. In this study, a total of 138 jujube bHLH (ZjbHLH) family members were screened from the transcriptome of the two jujube cultivars, ‘Junzao’ (JZ) and ‘Tailihong’ (TLH). Of these, 95 ZjbHLH genes were mapped to 12 chromosomes. A phylogenetic tree was constructed using 27 arabidopsis bHLH (AtbHLH) protein sequences of Arabidopsis thaliana (L.) Heynh. and 138 ZjbHLH protein sequences of jujube. The results show that the ZjbHLH family of jujube can be divided into 12 subfamilies. The three candidate genes, ZjGL3a, ZjGL3b and ZjTT8, related to anthocyanin synthesis, were classified into subgroup III. Meanwhile, ZjGL3a, ZjGL3b and ZjTT8 have high homology with the bHLH transcription factors involved in anthocyanin synthesis in other plants. In addition, it was found that the jujube ZjbHLH transcript family showed changing patterns of expression during fruit development. The relative expression levels of ZjGL3a, ZjGL3 and ZjTT8 were consistent with the changes of the anthocyanin contents in the two jujube cultivars examined. To better understand the anthocyanin synthesis pathway involved in ZjbHLH, a regulatory pathway model for anthocyanin synthesis was constructed. This model involves the processes of anthocyanin signal transduction, synthesis and transport.

Current Understanding of bHLH Transcription Factors in Plant Abiotic Stress Tolerance

“…Prunus amygdalus L.) [ 33 ]. Biosynthetic functions for more bHLH genes will likely be identified [ 34 ].…”

Genome-Wide Identification and Characterization of bHLH Transcription Factors Related to Anthocyanin Biosynthesis in Red Walnut (Juglans regia L.)

“…In this study, we identified 102 bHLH genes in the walnut genome, and their predominantly nuclear localization was in accordance with their function as TFs ( Supplementary Table S3). bHLH genes constitute large families, with 188 members in apple and 138 in jujube (Ziziphus jujuba; Mao et al, 2017;Shi et al, 2019) that can be divided into 15-25 subfamilies (Pires and Dolan, 2010). Our phylogenetic analysis showed that walnut bHLHs formed 15 subfamilies (Supplementary Figure S4A and Figure 3; Heim et al, 2003).…”

Investigation of the Nature of CgCDPK and CgbHLH001 Interaction and the Function of bHLH Transcription Factor in Stress Tolerance in Chenopodium glaucum

“…The bHLH TF has been reported to play important roles in plant growth/development, metabolism, and response to stress tolerance (Abe et al, 2003;Pillitteri and Torii, 2007;Zhao et al, 2008;Liu et al, 2013;Shi et al, 2019;Song et al, 2020;Sun et al, 2020). The best-characterized member in this FIGURE 9 | qRT-PCR analysis of the expression patterns of stress-related genes under different stresses in transgenic tobacco lines.…”