Institute of Crop, Gansu Academy of Agricultural Sciences, Lanzhou 730070, China.
Int J Mol Sci. 2023 Jul 2;24(13):11006. doi: 10.3390/ijms241311006.
Auxin response factors (ARFs) are critical components of the auxin signaling pathway, and are involved in diverse plant biological processes. However, genes have not been investigated in flax ( L.), an important oilseed and fiber crop. In this study, we comprehensively analyzed the gene family and identified 33 genes unevenly distributed on the 13 chromosomes of Longya-10, an oil-use flax variety. Detailed analysis revealed wide variation among the ARF family members and predicted nuclear localization for all proteins. Nineteen LuARFs contained a complete ARF structure, including DBD, MR, and CTD, whereas the other fourteen lacked the CTD. Phylogenetic analysis grouped the LuARFs into four (I-V) clades. Combined with sequence analysis, the LuARFs from the same clade showed structural conservation, implying functional redundancy. Duplication analysis identified twenty-seven whole-genome-duplicated genes and four tandem-duplicated genes. These duplicated gene pairs' K/K ratios suggested a strong purifying selection pressure on the genes. Collinearity analysis revealed that about half of the genes had homologs in other species, indicating a relatively conserved nature of the . The promoter analysis identified numerous hormone- and stress-related elements, and the qRT-PCR experiment revealed that all genes were responsive to phytohormone (IAA, GA3, and NAA) and stress (PEG, NaCl, cold, and heat) treatments. Finally, expression profiling of genes in different tissues by qRT-PCR indicated their specific functions in stem or capsule growth. Thus, our findings suggest the potential functions of in flax growth and response to an exogenous stimulus, providing a basis for further functional studies on these genes.
生长素响应因子（ARFs）是生长素信号通路的关键组成部分，参与多种植物生物学过程。然而，在亚麻（Linum usitatissimum）中，这些基因尚未被研究过，亚麻是一种重要的油料和纤维作物。在本研究中，我们全面分析了基因家族，并鉴定了 33 个基因，这些基因不均匀地分布在 Longya-10（一种油用亚麻品种）的 13 条染色体上。详细分析表明，ARF 家族成员之间存在广泛的变异，并预测所有蛋白质都具有核定位。19 个 LuARFs 包含完整的 ARF 结构，包括 DBD、MR 和 CTD，而其他 14 个则缺乏 CTD。系统发育分析将 LuARFs 分为四个（I-V）分支。结合序列分析，来自同一分支的 LuARFs 显示出结构保守性，暗示功能冗余。复制分析鉴定出 27 个全基因组复制基因和 4 个串联复制基因。这些复制基因对的 K/K 比值表明对这些基因存在强烈的纯化选择压力。共线性分析表明，大约一半的基因在其他物种中有同源基因，表明的相对保守性。启动子分析鉴定出许多与激素和应激相关的元件，qRT-PCR 实验表明，所有基因都对植物激素（IAA、GA3 和 NAA）和应激（PEG、NaCl、冷和热）处理有反应。最后，通过 qRT-PCR 对不同组织中的基因表达谱进行分析表明，它们在茎或蒴果生长中具有特定的功能。因此，我们的研究结果表明基因在亚麻生长和对外源刺激的响应中的潜在功能，为进一步研究这些基因的功能提供了基础。
