Wang Liyuan, Li Huawei, Suo Yujing, Han Weijuan, Diao Songfeng, Mai Yini, Wang Yiru, Yuan Jiaying, Ye Lingshuai, Pu Tingting, Zhang Qi, Sun Peng, Li Fangdong, Fu Jianmin
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland, Research Institute of Non-timber Forestry, Chinese Academy of Forestry, Zhengzhou, China.
Front Plant Sci. 2022 May 26;13:876086. doi: 10.3389/fpls.2022.876086. eCollection 2022.
Research on crop sexuality is important for establishing systems for germplasm innovation and cultivating improved varieties. In this study, androecious persimmon trees were treated with various concentrations of ethrel (100, 500, and 1,000 mg/L) and zeatin (1, 5, and 10 mg/L) to investigate the morphological, physiological, and molecular characteristics of persimmon. Ethrel at 1,000 mg/L and zeatin at 10 mg/L both significantly reduced the stamen length and pollen grain diameter in androecious trees. Ethrel treatment also led to reduced stamen development with degenerated cellular contents; zeatin treatment promoted the development of arrested pistils maintaining relatively normal mitochondrial morphology. Both treatments altered carbohydrate, amino acid, and endogenous phytohormone contents, as well as genes associated with hormone production and floral organ development. Thereafter, we explored the combined effects of four chemicals, including ethrel and zeatin, as well as zebularine and 5-azacytidine, both of which are DNA methylation inhibitors, on androecious persimmon flower development. Morphological comparisons showed that stamen length, pollen viability, and pollen grain diameter were significantly inhibited after combined treatment. Large numbers of genes involving in carbohydrate metabolic, mitogen-activated protein kinase (MAPK) signaling, and ribosome pathways, and metabolites including uridine monophosphate (UMP) and cyclamic acid were identified in response to the treatment, indicating complex regulatory mechanisms. An association analysis of transcriptomic and metabolomic data indicated that ribosomal genes have distinct effects on UMP and cyclamic acid metabolites, explaining how male floral buds of androecious persimmon trees respond to these exogenous chemicals. These findings extend the knowledge concerning sexual differentiation in persimmon; they also provide a theoretical basis for molecular breeding, high-yield cultivation, and quality improvement in persimmon.
作物性别研究对于建立种质创新体系和培育优良品种至关重要。在本研究中，对雄株柿树用不同浓度的乙烯利（100、500和1000毫克/升）和玉米素（1、5和10毫克/升）进行处理，以研究柿树的形态、生理和分子特征。1000毫克/升的乙烯利和10毫克/升的玉米素均显著降低了雄株柿树的雄蕊长度和花粉粒直径。乙烯利处理还导致雄蕊发育受抑，细胞内含物退化；玉米素处理促进了停滞雌蕊的发育，线粒体形态保持相对正常。两种处理均改变了碳水化合物、氨基酸和内源植物激素含量，以及与激素产生和花器官发育相关的基因。此后，我们探究了四种化学物质（包括乙烯利和玉米素，以及DNA甲基化抑制剂zebularine和5-氮杂胞苷）对雄株柿树花发育的联合作用。形态学比较表明，联合处理后雄蕊长度、花粉活力和花粉粒直径均受到显著抑制。鉴定出大量参与碳水化合物代谢、丝裂原活化蛋白激酶（MAPK）信号传导和核糖体途径的基因，以及包括尿苷一磷酸（UMP）和甜蜜素在内的代谢产物，表明存在复杂的调控机制。转录组学和代谢组学数据的关联分析表明，核糖体基因对UMP和甜蜜素代谢产物有不同影响，解释了雄株柿树雄花芽对这些外源化学物质的反应。这些发现扩展了关于柿树性别分化的知识；也为柿树的分子育种、高产栽培和品质改良提供了理论依据。
