高粱platz基因家族的鉴定、表达与自然等位变异分析

Identification, expression profiling, and natural allelic variation analysis of the platz gene family in sorghum

摘要:

Platz (plant AT-rich protein and zinc-binding protein)转录因子是Zn²⁺依赖的富含A/T序列的转录因子，主要作为转录因子在胁迫应答过程和生长发育调控中发挥重要作用。为系统探究高粱Platz转录因子的生物学功能及其在胁迫应答中的作用，本研究应用生物信息与分子生物学技术，对高粱中Platz转录因子理化性质、蛋白质二级结构、亚细胞定位、基因结构、系统进化树、启动子区顺式作用元件、表达模式、蛋白互作以及DNA变异进行了分析。结果表明在高粱中鉴定出了17个platz基因，不均匀地分布在除SBI-02、SBI-03、SBI-05、SBI-09外的6条染色体上，编码蛋白均为不稳定亲水性蛋白，流动性较好；基因结构差异较大，其启动子区含有较多与脱落酸、茉莉酸甲酯相关的顺式作用元件，高粱platz基因家族可分为5个亚族；在不同发育时期高粱组织中的RNA表达模式存在差异，platz基因在苗期表达水平高；在种子发育过程中SbPlatz7表达最高，另外SbPlatz5、SbPlatz3、SbFl1a、SbFl1b、SbGl6a和SbGl6b也均有表达，干旱胁迫下叶片中SbRHT25/Platz16表达上调，低氮和丝黑穗病菌侵染均会诱导SbPlatz3和SbPlatz7表达上调。自然等位变异分析显示SbPlatz存在较多的移码突变和密码子插入。本研究为解析platz在高粱中的功能提供了新的思路，为进一步了解高粱platz基因家族的进化机制和功能特征提供了有价值的信息，为提高抗逆性分子育种提供了参考和基因资源。

Abstract:

Plant AT-rich protein and zinc-dependent protein (Platz) transcription factors are Zn²⁺-binding and A/T-rich sequence-dependent that primarily function as transcriptional, playing crucial roles in stress responses and the regulation of growth and development. To systematically investigate the biological functions of sorghum Platz transcription factors and their roles in stress responses, we employed bioinformatics and molecular biology techniques to analyze their physicochemical properties, protein secondary structures, subcellular localization, gene structures, phylogenetic relationships, cis-acting elements in the promoter regions, expression patterns, protein-protein interactions, and DNA allelic variations of Platz transcription factors in sorghum. A total of 17 platz genes were identified in sorghum, with uneven distribution across six chromosomes (excluding SBI-02, SBI-03, SBI-05, and SBI-09). These genes encoded unstable hydrophilic proteins with favorable structural fluidity. Significant divergence in gene architecture was observed, and promoter regions were enriched with cis-acting elements linked to abscisic acid (ABA) and methyl jasmonate (MeJA). The phylogenetic analysis divided the platz family in sorghum into five subfamilies. RNA expression patterns of these transcription factors varied across different developmental stages, with platz genes exhibiting the highest expression during the seedling stage. During seed development, SbPlatz7 showed the highest expression, followed by SbPlatz5 and SbPlatz3, while SbFl1a, SbFl1b, SbGl6a, and SbGl6b were also expressed. Notably, drought stress induced upregulated expression of SbRHT25/Platz16 in leaves, whereas low nitrogen conditions and Sporisorium reilianum infection triggered upregulated expression of SbPlatz3 and SbPlatz7. Natural allelic variation analysis revealed frequent frameshift mutations and codon insertions in SbPlatz genes. This study gives novel insights into elucidating the functions of platz in sorghum, offers valuable information for further understanding the evolutionary mechanisms and functional characteristics of the platz gene family in this crop, and provides important references and gene resources for enhancing stress resistance in molecular breeding.