槟榔幼果脱落过程的生理生化指标变化规律

Changing patterns of physiological and biochemical indicators during the fruitlet abscission process of Areca catechu

槟榔(Areca catechu)开花后落果非常严重,是导致产量大幅度下降的关键因素。为探究槟榔落果过程中的生理生化变化机制,本研究以‘热研1号’槟榔为试验材料,喷施2 g·L^(-1)的乙烯利溶液,模拟槟榔幼果脱落过程,对其座果率、离层细胞形态、碳水化合物、内源激素含量以及相关基因表达进行了分析。结果显示,乙烯利处理后,槟榔离层的总糖和葡萄糖含量显著降低,而淀粉和蔗糖含量显著上升;1-氨基环丙烷羧酸(ACC)与脱落酸(ABA)含量显著增加,吲哚乙酸(IAA)和玉米素核苷(ZR)含量显著降低,但赤霉素(GA3)含量变化无明显规律;AcEIN3、AcERF3、AcNCED基因受乙烯诱导表达上调,而AcPIN-LIKE7基因表达下调,AcCKX11基因先上调后下调。综上结果表明,槟榔幼果发育过程中,其离层IAA、ZR含量降低以及ACC、ABA含量上升可能是诱导槟榔幼果脱落的关键信号因子,而碳水化合物供应中断可能促进了幼果的脱落。

After the process of flowering,the fruitlet abscission phenomenon in Areca catechu becomes highly pronounced,thereby serving as a crucial factor contributing to a substantial reduction in crop yield.In order to investigate the physiological and biochemical alterations that occur during the fruitlet abscission phenomenon in A.catechu,this study utilized'Reyan 1'A.catechu as the experimental material.A 2g·L^(-1)ethylene solution was sprayed to simulate the fruit drop process in A.catechu fruitlets.The analysis encompassed the fruitlet set rate,morphology of abscission zone(AZ)cells,carbohydrate content,endogenous hormone content,and expression of related genes.The findings indicate that the application of ethylene resulted in a significant decrease in the total sugar and glucose levels in the AZ of A.catechu.Conversely,there was a significant increase in the starch and sucrose contents.The contents of 1-aminocyclopropanecarboxylic acid(ACC)and abscisic acid(ABA)exhibited a substantial increase,whereas the contents of indole-3-acetic acid(IAA)and zeatin-riboside(ZR)experienced a significant decrease.However,the content of gibberellin A3(GA_3)did not display any discernible pattern of change.The expression of AcEIN3,AcERF3,and AcNCED genes was up-regulated by ethylene induction,while the expression of the AcPIN-LIKE7 gene was down-regulated,and the expression of the AcCKX11 gene was up-regulated first and then down-regulated.In conclusion,during the development of A.catechu fruitlets,the decrease in IAA and ZR contents and the increase in ACC and ABA contents may be key signaling factors inducing fruitlet abscission,while the interruption of carbohydrate supply may promote fruitlet abscission.