Transcriptome-wide identification and expression profile analysis of the bHLH family genes in Camellia sinensis
The tea plant is an important commercial horticulture crop cultivated worldwide. Yield and quality of this plant are influenced by abiotic stress. The bHLH family transcription factors play a pivotal role in the growth and development, including abiotic stress response, of plants. A growing number of bHLH proteins have been functionally characterized in plants. However, few studies have focused on the bHLH proteins in tea plants. In this study, 120 CsbHLH TFs were identified from tea plants using computational prediction method. Structural analysis detected 23 conservative residues, with over 50% identities in the bHLH domain. Moreover, 103 CsbHLH proteins were assumed to bind DNA and encompassed 98 E-Box binders and 85 G-Box binders. The CsbHLH proteins were grouped into 20 subfamilies based on phylogenetic analysis and a previous classification system. A survey of transcriptome profiling screened 22 and 39 CsbHLH genes that were upregulated under heat and drought stress. Nine CsbHLH genes were validated using qRT-PCR. Results were approximately in accordance with transcriptome data. These genes could be induced by one or more abiotic stresses.
KeywordsbHLH Transcription factor Phylogenetic analysis Expression pattern Abiotic stress Tea plant
ABA-inducible bHLH-type transcription factor
Basic Local Alignment Search Tool
C-repeat binding factor
Fragments per kilobase of transcript per million mapped reads
Hidden Markov model
Molecular evolutionary genetics analysis
Multiple Em for motif elicitation
National Center for Biotechnology Information
Quantitative real-time polymerase chain reaction
The research was supported by the National Natural Science Foundation of China (31570691).
Conceived and designed the experiments: JZ, XC. Performed the experiments: XC, YXW, ZWL, WLW, HL. Analyzed the data: XC, YXW, JZ. Contributed reagents/materials/analysis tools: JZ. Wrote the paper: XC. Revised the paper: JZ, XC, YXW. All authors read and approved the final manuscript.
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