Genome-wide characterization and expression analysis of bHLH gene family in physic nut (Jatropha curcas L.)

Abstract

The basic helix loop helix (bHLH) transcription factor perform essential roles in plant development and abiotic stress. Here, a total of 122 bHLH family members were identified from the physic nut (Jatropha curcas L.) genomic database. Chromosomal localization results showed that 120 members were located on 11 chromosomes. The phylogenetic tree manifested that the JcbHLHs could be grouped into 28 subfamilies. Syntenic analysis showed that there were 10 bHLH collinear genes among the physic nut, Arabidopsis thaliana and Oryza sativa. These genes, except JcbHLH84, were highly expressed in various tissues of the physic nut, implying a key role in plant development. Gene expression profiles showed that ten genes (especially JcbHLH33, JcbHLH45 and JcbHLH55) correspond to both salinity and drought stresses; while eight genes only respond to salinity and another eight genes only respond to drought stress. Moreover, the protein interaction network revealed that the JcbHLHs are involved in growth, development and stress signal transduction pathways. These discoveries will help to excavate several key genes may involve in salt or drought stresses and seed development, elucidate the complex transcriptional regulation mechanism of JcbHLH genes and provide the theoretical basis for stress response and genetic improvement of physic nut.

Genome-wide identification of bHLH transcription factors and functional analysis in salt gland development of the recretohalophyte sea lavender (Limonium bicolor)

“…ZmbHLH genes are expressed highly in maize during root, leaf, and seed development and might participate in multiple plant growth and developmental processes [ 40 ]. In physic nut ( Jatropha curcas ), bHLH genes other than JcbHLH84 are expressed in various parts, implying they play crucial roles in the overall growth of plants [ 41 ]. Consequently, bHLH proteins function in epidermal structure development in many species.…”

“…35S: PRE6 transgenic sorghum plants show increased salt tolerance, and PREs might play redundant roles in regulating salt responses [ 42 ]. In physic nut, eight bHLH genes are closely related to salinity and others respond to drought stress [ 41 ]. In Hibiscus hamabo Sieb.…”

Genome-Wide Analysis of bHLH Family Genes and Identification of Members Associated with Cold/Drought-Induced Photoinhibition in Kandelia obovata

“…We further determined the responses of KobHLH genes to cold and drought stresses. As illustrated in Figure 7B, the expression levels of KobHLH6, 14,26,22,52,30,74,24,50, and 53 were up-regulated, whereas those of KobHLH29, 59, 69, 60, 7, 17, and 34 were downregulated after cold treatment. These cold-responsive genes exhibited consistent…”

“…The identification of conserved motifs in KobHLH proteins was accomplished using the MEME Suite (http://meme.sdsc.edu/meme/itro.html, accessed on 20 October 2022). The maximum number (10) of motifs and an optimal width ranging from 6 to 200 residues were set [50]. Analysis of the exon/intron structures of the KobHLH genes was performed using the Gene Structure Display Server (GSDS, http://gsds.cbi.pku.edu.cn/, accessed on 20 October 2022) [51].…”

Basic Helix-Loop-Helix Transcription Factors: Regulators for Plant Growth Development and Abiotic Stress Responses

“… Phylogenetic analysis of the species based on genome-wide association study of the basic helix-loop-helix (bHLH) family. The total number of bHLH transcription factors identified from the genome of each species are indicated [ 5 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 ]. …”