Ke Qinglin, Tao Wenjing, Li Tingting, Pan Wenqiu, Chen Xiaoyun, Wu Xiaoyu, Nie Xiaojun, Cui Licao
1College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang330045, Jiangxi, China; 2State Key Laboratory of Crop Stress Biology in Arid Areas and College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China.
Curr Genomics. 2020 Dec;21(8):621-644. doi: 10.2174/1389202921999201102165537.
The basic helix-loop-helix (bHLH) transcription factor is one of the most important gene families in plants, playing a key role in diverse metabolic, physiological, and developmental processes. Although it has been well characterized in many plants, the significance of the bHLH family in barley is not well understood at present.
Through a genome-wide search against the updated barley reference genome, the genomic organization, evolution and expression of the bHLH family in barley were systematically analyzed.
We identified 141 bHLHs in the barley genome () and further classified them into 24 subfamilies based on phylogenetic analysis. It was found that in the same subfamily shared a similar conserved motif composition and exon-intron structures. Chromosome distribution and gene duplication analysis revealed that segmental duplication mainly contributed to the expansion of and the duplicated genes were subjected to strong purifying selection. Furthermore, expression analysis revealed that were widely expressed in different tissues and also involved in response to diverse abiotic stresses. The co-expression network was further analyzed to underpin the regulatory function of . Finally, 25 genes were selected for qRT-PCR validation, the expression profiles of showed diverse patterns, demonstrating their potential roles in relation to stress tolerance regulation.
This study reported the genome organization, evolutionary characteristics and expression profile of the bHLH family in barley, which not only provide the targets for further functional analysis, but also facilitate better understanding of the regulatory network bHLH genes involved in stress tolerance in barley.
基本螺旋-环-螺旋（bHLH）转录因子是植物中最重要的基因家族之一，在多种代谢、生理和发育过程中起关键作用。尽管它在许多植物中已得到充分表征，但目前对大麦中bHLH家族的重要性了解甚少。
通过对更新后的大麦参考基因组进行全基因组搜索，系统分析了大麦中bHLH家族的基因组组织、进化和表达情况。
我们在大麦基因组中鉴定出141个bHLH，并基于系统发育分析将它们进一步分为24个亚家族。发现同一亚家族中的成员具有相似的保守基序组成和外显子-内含子结构。染色体分布和基因复制分析表明，片段重复主要促成了bHLH的扩增，并且复制的基因受到强烈的纯化选择。此外，表达分析表明，bHLH在不同组织中广泛表达，并且还参与对多种非生物胁迫的响应。进一步分析共表达网络以加强bHLH的调控功能。最后，选择25个基因进行qRT-PCR验证，其表达谱显示出不同的模式，证明了它们在胁迫耐受性调控方面的潜在作用。
本研究报道了大麦中bHLH家族的基因组组织、进化特征和表达谱，这不仅为进一步的功能分析提供了靶点，也有助于更好地理解大麦中参与胁迫耐受性的bHLH基因调控网络。
