Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Shandong, 250014, China; Laboratory of Plant Molecular Biology & Crop Gene Editing, School of Life Sciences, Linyi University, Linyi, 276000, China.
Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Shandong, 250014, China.
Plant Physiol Biochem. 2024 Mar;208:108462. doi: 10.1016/j.plaphy.2024.108462. Epub 2024 Feb 23.
NAC transcription factors regulate plant growth, development, and stress responses. However, the number, types, and biological functions of Limonium bicolor LbNAC genes have remained elusive. L. bicolor secretes excessive salt ions through salt glands on its stems and leaves to reduce salt-induced damage. Here, we identified 63 NAC members (LbNAC1-63) in L. bicolor, which were unevenly distributed across eight chromosomes. Cis-elements in the LbNAC promoters were related to growth and development, stress responses, and phytohormone responses. We observed strong colinearity between LbNACs and GmNACs from soybean (Glycine max). Thus, LbNAC genes may share similar functions with GmNAC genes. Expression analysis indicated that 16 LbNAC genes are highly expressed in roots, stems, leaves, and flowers, whereas 17 LbNAC genes were highly expressed throughout salt gland development, suggesting that they may regulate this developmental stage. Silencing LbNAC54 in L. bicolor decreased salt gland density, salt secretion from leaves, and overall salt tolerance. In agreement, genes related to salt gland development were significantly downregulated in LbNAC54-silenced lines. Our findings shed light on LbNAC genes and help elucidate salt gland development and salt secretion in L. bicolor. Our data also provide insight into NAC functions in halophytes.
NAC 转录因子调节植物的生长、发育和应激反应。然而，其数量、类型和生物学功能在二色补血草（Limonium bicolor LbNAC）中仍未得到明确。二色补血草通过茎和叶上的盐腺分泌过多的盐离子，以减轻盐诱导的损伤。在这里，我们鉴定了 63 个 NAC 成员（LbNAC1-63）在二色补血草中，它们不均匀地分布在 8 条染色体上。LbNAC 启动子中的顺式元件与生长发育、应激反应和植物激素反应有关。我们观察到 LbNAC 和大豆（Glycine max）中的 GmNAC 之间存在强烈的共线性。因此，LbNAC 基因可能与 GmNAC 基因具有相似的功能。表达分析表明，16 个 LbNAC 基因在根、茎、叶和花中高度表达，而 17 个 LbNAC 基因在整个盐腺发育过程中高度表达，表明它们可能调节这一发育阶段。在二色补血草中沉默 LbNAC54 降低了盐腺密度、叶片盐分泌和整体耐盐性。与此一致，在 LbNAC54 沉默系中，与盐腺发育相关的基因显著下调。我们的研究结果阐明了 LbNAC 基因，有助于阐明二色补血草中盐腺的发育和盐的分泌。我们的数据还为 NAC 在盐生植物中的功能提供了新的见解。
