背景:植物特异性TIFY蛋白广泛存在于陆生植物中,在植物逆境反应中起重要作用。虽然枇杷染色体水平的基因组已经发表,缺乏对枇杷中TIFY家族的研究。因此,通过构建系统进化树对EjTIFY基因家族进行了生物信息学分析,染色体定位,基因结构,和逆境表达谱在这项研究中。
结果:鉴定了26个EjTIFY基因,并将其分为四个亚家族(ZML,JAZ,PPD,和TIFY)基于它们的结构域。24个EjTIFY基因不规则分布在17条染色体中的11条,其余两个基因呈片段分布。我们在枇杷基因组中鉴定出15个协变量TIFY基因对,其中13例涉及大规模染色体间节段重复事件,其中两个参与了串联重复事件。许多非生物胁迫顺式元件广泛存在于启动子区域。对Ka/Ks比率的分析表明,EjTIFY家族的同源物主要进行纯化选择。对RNA-seq数据的分析表明,在赤霉素处理下,芽中总共表达了五个差异表达基因(DEG),而只有一个基因在叶片中显著差异表达;在低温和高温胁迫下,有显著差异表达的基因,EjJAZ15基因在低温和高温胁迫下均显著上调。盐胁迫条件下的RNA-seq和qRT-PCR表达分析显示,EjJAZ2,EjJAZ4和EjJAZ9对枇杷植物的盐胁迫有反应,通过JA途径促进对盐胁迫的抗性。系统总结了盐胁迫下枇杷TIFY基因在茉莉酸途径中的反应模型。
结论:这些结果为将来探索其他EjTIFY基因的特征和功能提供了理论基础。本研究也为枇杷耐盐胁迫育种的进一步研究提供了理论依据。RT-qPCR分析显示,在盐胁迫条件下,三种EjTIFY基因之一的表达量增加,两种基因的表达量降低,表明EjTIFY在盐胁迫条件下表现出不同的表达模式。
BACKGROUND: Plant-specific TIFY proteins are widely found in terrestrial plants and play important roles in plant adversity responses. Although the genome of loquat at the chromosome level has been published, studies on the TIFY family in loquat are lacking. Therefore, the EjTIFY gene family was bioinformatically analyzed by constructing a phylogenetic tree, chromosomal localization, gene structure, and adversity expression profiling in this study.
RESULTS: Twenty-six EjTIFY genes were identified and categorized into four subfamilies (ZML, JAZ, PPD, and TIFY) based on their structural domains. Twenty-four EjTIFY genes were irregularly distributed on 11 of the 17 chromosomes, and the remaining two genes were distributed in fragments. We identified 15 covariate TIFY gene pairs in the loquat genome, 13 of which were involved in large-scale interchromosomal segmental duplication events, and two of which were involved in tandem duplication events. Many abiotic stress cis-elements were widely present in the promoter region. Analysis of the Ka/Ks ratio showed that the paralogous homologs of the EjTIFY family were mainly subjected to purifying selection. Analysis of the RNA-seq data revealed that a total of five differentially expressed genes (DEGs) were expressed in the shoots under gibberellin treatment, whereas only one gene was significantly differentially expressed in the leaves; under both low-temperature and high-temperature stresses, there were significantly differentially expressed genes, and the EjJAZ15 gene was significantly upregulated under both low- and high-temperature stress. RNA-seq and qRT-PCR expression analysis under salt stress conditions revealed that EjJAZ2, EjJAZ4, and EjJAZ9 responded to salt stress in loquat plants, which promoted resistance to salt stress through the JA pathway. The response model of the TIFY genes in the jasmonic acid pathway under salt stress in loquat was systematically summarized.
CONCLUSIONS: These results provide a theoretical basis for exploring the characteristics and functions of additional EjTIFY genes in the future. This study also provides a theoretical basis for further research on breeding for salt stress resistance in loquat. RT-qPCR analysis revealed that the expression of one of the three EjTIFY genes increased and the expression of two decreased under salt stress conditions, suggesting that EjTIFY exhibited different expression patterns under salt stress conditions.