The Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-Bioengineering, Guizhou University, Guiyang, 550025, Guizhou Province, China.
Guizhou Plant Conservation Technology Center, Biotechnology Institute of Guizhou, Guizhou Academy of Agricultural Sciences, Guiyang, 550006, Guizhou Province, China.
Sci Rep. 2024 Jun 19;14(1):14111. doi: 10.1038/s41598-024-65020-5.
Legumin A is a seed storage protein that provides nutrients for seed germination. The purpose of this study was to describe the structure and expression pattern of the EuLEGA gene in Eucommia ulmoides Oliver (E. ulmoides) and to infer its functional role. The 1287 bp coding sequence of the EuLEGA CDS of the EuLEGA gene, encoding a protein containing 428 amino acid residues, was cloned. The structure predicted that the protein belonged to the RmlC (deoxythymidine diphosphates, dTDP)-4-dehydrorhamnose 3,5-epimerase)-like cupin conserved domain family, which contains both RmlC, a key enzyme for the synthesis of rhamnose and legumin A. The overexpression (OE) vector of the EuLEGA gene was constructed and genetically transformed into tobacco and E. ulmoides; the RNA interference (RNAi) vector of the EuLEGA gene was constructed and genetically transformed into E. ulmoides; and the contents of legumin A and rhamnose were detected. The results showed that the EuLEGA gene could significantly increase the content of legumin A in transgenic tobacco leaves and transgenic E. ulmoides regenerative buds, and the OE of this gene in E. ulmoides could promote an increase in rhamnose content. RNAi caused a significant decrease in the legumin A content in the regenerated buds of E. ulmoides. These was a significant increase in legumin A in the transgenic tobacco seeds, and these results indicate that the expression of the EuLEGA gene is closely related to the accumulation of legumin A. Subcellular localization studies revealed that EuLEGA is localized to the cytoplasm with the vacuolar membrane. Analysis of the EuLEGA gene expression data revealed that the expression level of the EuLEGA gene in the samaras was significantly greater than that in the leaves and stems. In addition, the study also demonstrated that GA can upregulate the expression levels of the EuLEGA gene, while ABA and MeJA can downregulate its expression levels.
豆科球蛋白 A 是一种种子贮藏蛋白，可为种子萌发提供营养。本研究旨在描述杜仲（Eucommia ulmoides Oliver）EuLEGA 基因的结构和表达模式，并推断其功能作用。克隆了 EuLEGA 基因的 1287bp 编码序列（CDS），编码一个含有 428 个氨基酸残基的蛋白质。预测该蛋白属于 RmlC（去氧胸苷二磷酸，dTDP）-4-脱水鼠李糖 3,5-差向异构酶）样 cupin 保守结构域家族，该家族既包含合成鼠李糖和豆球蛋白 A 的关键酶 RmlC。构建了 EuLEGA 基因的过表达（OE）载体并遗传转化到烟草和杜仲中；构建了 EuLEGA 基因的 RNA 干扰（RNAi）载体并遗传转化到杜仲中；检测了豆球蛋白 A 和鼠李糖的含量。结果表明，EuLEGA 基因可显著增加转基因烟草叶片和转基因杜仲再生芽中的豆球蛋白 A 含量，OE 该基因在杜仲中可促进鼠李糖含量的增加。RNAi 导致杜仲再生芽中的豆球蛋白 A 含量显著降低。转基烟草种子中的豆球蛋白 A 含量显著增加，表明 EuLEGA 基因的表达与豆球蛋白 A 的积累密切相关。亚细胞定位研究表明，EuLEGA 定位于具有液泡膜的细胞质中。EuLEGA 基因表达数据分析表明，EuLEGA 基因在翅果中的表达水平明显高于叶片和茎中的表达水平。此外，研究还表明 GA 可以上调 EuLEGA 基因的表达水平，而 ABA 和 MeJA 可以下调其表达水平。
