Study On The Effect Of ABA Signal In Fruit Development And Maturation Process In‘Zunla-1’

According to the respiration process of fruit development and maturation, the horticultural plant fruit can be divided into respiratory climacteric and non-climacteric types. Recent studies have shown that the plant hormone abscisic acid(Abscisic Acid,ABA) may be the significant initiation factor and plays an important role in non-climacteric fruit mature and senescence. Pepper is one of the most important solanaceous vegetable crops, w which are belonging to non-climacteric fruit. There are little reports on the relationship between ABA signal and pepper fruit development and maturity. In this study, ’‘Zunla-1’ chili pepper fruits were treated by ABA. We are trying to explore the effect of ABA treatment on pepper coloring and fruit quality, as well as investigate the expression profiles of key genes in the ABA anabolic processes,and finally reveal the mechanism of ABA in the regulation of pepper fruit development and ripening. The main results obtained are as follows:1. The endogenous ABA content continuous increase during the pepper fruit development and maturation. The growth rates continue to increase with the development process, indicating that ABA may play an important role in the pepper fruit maturation process.2. Exogenous ABA treatment can accelerate the development and maturation of pepper fruit. With the increasing concentration of ABA, more obvious accelerate can be investigated. The concentration of soluble sugar, soluble protein, SOD enzyme,and POD enzyme and malondialdehyde activity will be effected by exogenous ABA during the pepper fruit development process, as well as during the maturation process.3. With the homology analysis, three NCED genes from pepper genome are verified. Bioinformatics showed that all members are included RPE65 conserved domains. The expression of the three NCED genes in pepper fruit development and maturation process were analyzed, the results showed an upward expression of Capana00g003114 and Capana05g002276 during pepper fruit maturation. We speculated that they may participate in the regulation of ABA during the pepper fruit development and maturation and play a certain role.4. With the homology analysis, three ASR genes from chili genome are verified(Capana04g001287, Capana04g001288 and Capana04g001289). Bioinformaticsresults confirmed that all chili ASR genes contain an ABA / WDS conserved domains.The expression of these three genes during pepper fruit development and maturation was analyzed. We known that Capana04g001288 express stably in mature green fruit,breaker and ripening red fruit. Capana04g001289 express stably in mature green fruit,reduce at breaker, while be a significantly increase in the red ripe stage.5. Analyzing eight ABA metabolism-related genes, the results showed that Capana01g000984 and Capana10g002513 showed the similar expression character.There is an expression increasing be detected from green fruit stage to color changing stage, while the expression reduced the red ripe stage. Capana03g000145 、Capana03g002801、Capana08g002366 and Capana08g00236 showed an increasing expression during the fruit development and maturation. And the maximum concentration is detected in red ripe stage, which is agreed to the electronic profiles results. Capana00g004573 expression in all stages and there is no significant difference among them. The expression of Capana06g000163 could be detected in green fruit stage and color changing stage, while less expression in red ripe stage. We speculated that the gene expression characters of these genes are related to the ABA signal inducing pepper fruit maturation. But they may have the different mechanisms.