热休克蛋白20(Hsp20)在应对干旱等非生物胁迫中起着非常重要的作用。在生菜(LactucasativaL.)中,这个基因家族知之甚少。本研究利用生物信息学方法对36个生菜Hsp20家族成员进行鉴定,命名为LsHsp20-1~LsHsp20-36。亚细胞定位结果表明,LsHsp20蛋白家族的26个成员定位于细胞质和细胞核。此外,在LsHsp20蛋白家族中鉴定出15个保守结构域,氨基酸的数量从8到50。基因结构分析显示15个基因(41.7%)没有内含子,20个基因(55.5%)有一个内含子。LsHsp20二级结构的比例为无规卷曲>α螺旋>延伸链>β转角。染色体定位分析表明,36个基因在9条染色体上分布不均,四对基因是共线的。共线基因的Ka/Ks比小于1,表明纯化选择在紫花苜蓿进化过程中占主导地位。生菜和拟南芥中有13对基因共线,生菜和番茄中14对基因共线。根据系统发育分析,将总共36种LsHsp20蛋白分为12个亚组。三种类型的顺式作用元件,即,非生物和生物应激反应,植物激素反应,和植物发育相关的元素,在生菜LsHsp20家族中被鉴定。采用qRT-PCR分析干旱处理第7天或第14天显著上调的23个LsHsp20基因的表达水平,在干旱处理的第14天和第7天,两个基因(LsHsp20-12和LsHsp20-26)的表达水平分别显着增加了153倍和273倍,分别。本研究结果为生菜中LsHsp20基因家族的研究提供了全面的信息,为进一步阐明Hsp20的生物学功能奠定了坚实的基础。为LsHsp20家族在莴苣抗旱性中的调控机制提供了有价值的信息。
Heat shock protein 20 (Hsp20) plays a very important role in response to abiotic stressors such as drought; however, in
lettuce (Lactuca sativa L.), this gene family is poorly understood. This study used bioinformatics methods to identify 36 members of the
lettuce Hsp20 family, which were named LsHsp20-1~LsHsp20-36. Subcellular localization results revealed that 26 members of the LsHsp20 protein family localized to the cytoplasm and nucleus. Additionally, 15 conserved domains were identified in the LsHsp20 protein family, with the number of amino acids ranging from 8 to 50. Gene structure analysis revealed that 15 genes (41.7%) had no introns, and 20 genes (55.5%) had one intron. The proportion of the LsHsp20 secondary structure was random coil > alpha helix > extended strand > beta turn. Chromosome positioning analysis indicated that 36 genes were unevenly distributed on nine chromosomes, and four pairs of genes were collinear. The Ka/Ks ratio of the collinear genes was less than 1, indicating that purifying selection dominated during L. sativa evolution. Thirteen pairs of genes were collinear in
lettuce and Arabidopsis, and 14 pairs of genes were collinear in
lettuce and tomato. A total of 36 LsHsp20 proteins were divided into 12 subgroups based on phylogenetic analysis. Three types of cis-acting elements, namely, abiotic and biotic stress-responsive, plant hormone-responsive, and plant development-related elements, were identified in the lettuce LsHsp20 family. qRT-PCR was used to analyze the expression levels of 23 LsHsp20 genes that were significantly upregulated on the 7th or 14th day of drought treatment, and the expression levels of two genes (LsHsp20-12 and LsHsp20-26) were significantly increased by 153-fold and 273-fold on the 14th and 7th days of drought treatment, respectively. The results of this study provide comprehensive information for research on the LsHsp20 gene family in
lettuce and lay a solid foundation for further elucidation of Hsp20 biological functions, providing valuable information on the regulatory mechanisms of the LsHsp20 family in lettuce drought resistance.