College of Life Sciences, Qingdao Agricultural University, Key Lab of Plant Biotechnology in Universities of Shandong Province, Qingdao, China.
State Key Laboratory of Crop Biology/Agronomy College, Shandong Agricultural University, Taian, Shandong, China.
BMC Plant Biol. 2021 Dec 4;21(1):569. doi: 10.1186/s12870-021-03358-y.
Cotton is not only a major textile fiber crop but also a vital oilseed, industrial, and forage crop. Oleosins are the structural proteins of oil bodies, influencing their size and the oil content in seeds. In addition, the degradation of oleosins is involved in the mobilization of lipid and oil bodies during seed germination. However, comprehensive identification and the systematic analysis of the Oleosin gene (OLEOs) family have not been conducted in cotton.
An in-depth analysis has enabled us to identify 25 and 24 OLEOs in tetraploid cotton species G. hirsutum and G. barbadense, respectively, while 12 and 13 OLEOs were identified in diploid species G. arboreum and G. raimondii, respectively. The 74 OLEOs were further clustered into three lineages according to the phylogenetic tree. Synteny analysis revealed that most of the OLEOs were conserved and that WGD or segmental duplications might drive their expansion. The transmembrane helices in GhOLEO proteins were predicted, and three transmembrane models were summarized, in which two were newly proposed. A total of 24 candidate miRNAs targeting GhOLEOs were predicted. Three highly expressed oil-related OLEOs, GH_A07G0501 (SL), GH_D10G0941 (SH), and GH_D01G1686 (U), were cloned, and their subcellular localization and function were analyzed. Their overexpression in Arabidopsis increased seed oil content and decreased seed germination rates.
We identified OLEO gene family in four cotton species and performed comparative analyses of their relationships, conserved structure, synteny, and gene duplication. The subcellular localization and function of three highly expressed oil-related OLEOs were detected. These results lay the foundation for further functional characterization of OLEOs and improving seed oil content.
棉花不仅是主要的纺织纤维作物，还是重要的油料作物、工业作物和饲料作物。油体蛋白是油体的结构蛋白，影响油体的大小和种子中的油含量。此外，油体蛋白的降解参与了种子萌发过程中脂质和油体的动员。然而，棉属植物中油体蛋白基因（OLEOs）家族的全面鉴定和系统分析尚未进行。
深入分析能够分别在四倍体棉花物种陆地棉和海岛棉中鉴定出 25 个和 24 个 OLEOs，而在二倍体物种亚洲棉和雷蒙德氏棉中分别鉴定出 12 个和 13 个 OLEOs。根据系统发育树，这 74 个 OLEOs 进一步聚类为三个谱系。共线性分析表明，大多数 OLEOs 是保守的，WGD 或片段重复可能推动了它们的扩张。预测了 GhOLEO 蛋白中的跨膜螺旋，并总结了三种跨膜模型，其中两种是新提出的。共预测到 24 个靶向 GhOLEOs 的候选 miRNA。克隆了三个高表达的油相关 OLEOs，GH_A07G0501（SL）、GH_D10G0941（SH）和 GH_D01G1686（U），并分析了它们的亚细胞定位和功能。它们在拟南芥中的过表达增加了种子的含油量，降低了种子的发芽率。
我们在四个棉花物种中鉴定了 OLEO 基因家族，并对它们的关系、保守结构、共线性和基因复制进行了比较分析。检测了三个高表达的油相关 OLEOs 的亚细胞定位和功能。这些结果为进一步研究 OLEOs 的功能特征和提高种子含油量奠定了基础。
