Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, China Agricultural University, 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, China.
The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, 12 Zhongguancun South St, Haidian District, Beijing, 100081, China.
Sci Rep. 2018 Oct 22;8(1):15583. doi: 10.1038/s41598-018-33782-4.
G proteins regulate shoot, root, and epidermis development, as well as biotic stress tolerance in plants; however, most studies have examined model plants and less attention has been paid to the function of G proteins in horticultural plants. Here, we identified a G protein, CsGPA1, from cucumber and studied its function in seedling development of cucumbers. CsGPA1 is a peptide of 392 amino acids with a predicted molecular mass of 44.6 kDa. Spatiotemporal expression analysis found that endogenous CsGPA1 was highly expressed in roots and young leaves. Immunohistochemical assay revealed that functional CsGPA1 was present in the plasma membranes of the epidermis and cortex, and in the cytosol of the endodermis, parenchyma, and vasculature of root meristematic cells. In comparison with wild-type seedlings, CsGPA1-overexpressing transgenic lines exhibited enhanced seed germination and earlier seedling development including hypocotyl elongation and root growth. In contrast, RNAi silencing of the CsGPA1 gene inhibited seedling growth and development. Further study showed that CsGPA1 controled hypocotyl elongation and root growth via promoting cell size and the meristem of hypocotyl and root tip cells of cucumber plants. Our study expands the roles of G proteins in plants and helps to elucidate the mechanism by which cucumber regulates early seedling development.
G 蛋白调节植物的芽、根和表皮发育以及生物胁迫耐受性；然而，大多数研究都集中在模式植物上，对园艺植物中 G 蛋白的功能关注较少。在这里，我们从黄瓜中鉴定了一个 G 蛋白，CsGPA1，并研究了它在黄瓜幼苗发育中的功能。CsGPA1 是一个由 392 个氨基酸组成的肽，预测分子量为 44.6kDa。时空表达分析发现，内源性 CsGPA1 在根和嫩叶中高度表达。免疫组织化学分析表明，功能性 CsGPA1 存在于根分生组织细胞的表皮和皮层的质膜以及内皮层、薄壁组织和脉管系统的细胞质中。与野生型幼苗相比，CsGPA1 过表达转基因系表现出增强的种子萌发和更早的幼苗发育，包括下胚轴伸长和根生长。相比之下，CsGPA1 基因的 RNAi 沉默抑制了幼苗的生长和发育。进一步的研究表明，CsGPA1 通过促进黄瓜植株下胚轴和根尖细胞的细胞大小和分生组织来控制下胚轴伸长和根生长。我们的研究扩展了 G 蛋白在植物中的作用，并有助于阐明黄瓜调节早期幼苗发育的机制。
