School of Life Sciences, Anhui Agricultural University, Hefei 230036, China.
Int J Mol Sci. 2022 Jun 24;23(13):7054. doi: 10.3390/ijms23137054.
The (small auxin-up RNA) gene family is the biggest family of early auxin response genes in higher plants and has been associated with the control of a variety of biological processes. Although genes had been identified in several genomes, no systematic analysis of the gene family has been reported in Chinese white pear. In this study, comparative and systematic genomic analysis has been performed in the gene family and identified a total of 116 genes from the Chinese white pear. A phylogeny analysis revealed that the family could be classified into four groups. Further analysis of gene structure (introns/exons) and conserved motifs showed that they are diverse functions and -specific domains. The most frequent mechanisms are whole-genome duplication (WGD) and dispersed duplication (DSD), both of which may be important in the growth of the gene family in Chinese white pear. Moreover, cis-acting elements of the genes were found in promoter regions associated with the auxin-responsive elements that existed in most of the upstream sequences. Remarkably, the qRT-PCR and transcriptomic data indicated that and were significantly expressed in fruit ripening. Subsequently, subcellular localization experiments revealed that and were localized in the nucleus. Moreover, and were screened for functional verification, and Dangshan pear and frandi strawberry were transiently transformed. Finally, the effects of these two genes on stone cells and lignin were analyzed by phloroglucinol staining, Fourier infrared spectroscopy, and qRT-PCR. It was found that promoted the synthesis and accumulation of stone cells and lignin, inhibited the synthesis and accumulation of stone cells and lignin. In conclusion, these results indicate that and are predominantly responsible for lignin inhibit synthesis, which provides a basic mechanism for further study of gene functions.
（小分子生长素 RNA）基因家族是高等植物中最早的生长素响应基因家族中最大的家族，与多种生物过程的控制有关。尽管已经在几个基因组中鉴定出了 基因，但在我国白梨中尚未报道对 基因家族进行系统分析。在这项研究中，对 基因家族进行了比较和系统的基因组分析，从我国白梨中鉴定出了总共 116 个基因。系统发育分析表明， 家族可分为四个组。进一步分析基因结构（内含子/外显子）和保守基序表明，它们具有多种功能和 -特异性结构域。最常见的机制是全基因组复制（WGD）和分散复制（DSD），这两者可能在我国白梨 基因家族的生长中起重要作用。此外，在与生长素反应元件相关的启动子区域中发现了 基因的顺式作用元件，这些元件存在于大多数上游序列中。值得注意的是，qRT-PCR 和转录组数据表明 和 在果实成熟过程中表达量显著。随后，亚细胞定位实验表明 和 定位于细胞核。此外，筛选了 和 进行功能验证，并瞬时转化了砀山梨和佛朗蒂草莓。最后，通过间苯三酚染色、傅里叶红外光谱和 qRT-PCR 分析了这两个基因对石细胞和木质素的影响。结果发现， 促进了石细胞和木质素的合成和积累， 抑制了石细胞和木质素的合成和积累。综上所述，这些结果表明 和 主要负责抑制木质素的合成，为进一步研究 基因功能提供了基础机制。
