脱落酸对薄皮甜瓜果实β-胡萝卜素积累的影响OA

[Objective]Study was carried out to clarify the effect of abscisic acid(ABA)on the accumulation of β-carotene in oriental melon fruit,and to reveal its mechanism in fruit ripening and nutritional quality,so as to rationally use ABA to promote the accumulation of β-carotene in fruits,improve the flavor quality,nutritional value and economic benefits of oriental melons,and provide a theoretical basis for cultivating high-quality oriental melons that meet people's needs.[Method]The orange flesh variety HDB was used as the test material,the fruit was sprayed with 100 mg·L-1 ABA and its inhibitor Nordihydroguaiaretic acid(NDGA)on 20 days after flowering(when the flesh color was not transformed).Samples were taken on 0,1,3,5,7,9,11,13,15 days after treatment to determine the soluble solid content(SSC),flesh color,ethylene production,endogenous ABA content,β-carotene content and gene expression of synthesis pathway in the melon fruit.[Results]The ABA treatment could advance the accumulation of soluble solids in melon fruit,but does not affect the final SSC.It can accelerate the decline of the brightness of melon flesh and promote its early color change;it can increase ethylene production and endogenous ABA content in melon fruit;and it could promote the early accumulation of β-carotene in melon fruit,without affecting the final content.And it could significantly enhance the relative expression of synthesis genes(CmPSY and CmLCYB)related to the carotenoid metabolic pathway in melon fruit.Conversely,the NDGA treatment inhibited the synthesis of endogenous ABA and accumulation of β-carotene and significantly reduced the content of β-carotene in fruit.[Conclusion]Exogenous ABA treatment can promote the synthesis of ethylene and endogenous ABA in melon fruits,promote the ripening of melon fruits,improve the expression of β-carotene synthesis genes in melon fruit,and promote the synthesis and accumulation of β-carotene in melon fruit.The results of the experiment can provide a theoretical basis for using ABA to increase the β-carotene content of oriental melon fruit.