采后处理对香蕉果实ACC合成酶基因表达的影响

香蕉属于呼吸跃变型果实,ACC合成酶(ACS)是乙烯合成路径中的关键限速酶,为了明确调控香蕉果实成熟关键ACS基因,对采后香蕉果实用乙烯利、自然成熟和1-MCP等处理,并利用实时荧光定量PCR分析ACS基因家族成员在果实成熟过程中的表达情况。结果表明,不同家族成员在3种处理中的表达趋势及表达丰度不一致,MaACS4在乙烯利、自然成熟和1-MCP处理后的表达趋势一致,均为前期变化不大,成熟时快速增加,但最终上调倍数小于10。MaACS6表达量在乙烯利和1-MCP处理中先下降后增加,在自然成熟中先增加后下降。MaACS10在三种处理中,表达量在前期比较低且变化不大,但在成熟时急剧增加并达到峰值,最终上调倍数达到约1700倍。MaACS13表达量在乙烯利和1-MCP处理中先下降后增加再下降,在自然成熟中前期变化不大,但成熟时显著下降,基于此结果,推测MaACS10是调控香蕉成熟的关键基因。

Effect of postharvest treatment on ACC synthase gene expression in banana fruit

Banana is a kind of climacteric respiration fruit. ACC synthase (ACS) is the key rate-limiting enzyme in the ethylene synthesis pathway. In order to clearly the key ACS genes regulating fruit ripening, the postharvest banana fruit were treated with ethephon, natural maturation and 1-MCP. Then, the expression of ACS gene family members were analyzed during fruit maturation by real-time fluorescence quantitative PCR. The results showed that the expression trend and expression abundance of different family members were inconsistent in the three treatments. The expression trend of MaACS4 was the same after ethephon, natural maturation and 1-MCP treatment. Which changed little in the early stage, increased rapidly at maturity, but the final up-regulation was less than 10 times. MaACS6 expression was decreased first and then increased in the treatment of ethephon and 1-MCP, but increased first and then decreased in the natural maturation. The expression level of MaACS10 was relatively low in the early stage, but it increased sharply and reached the peak when it matured, which reached about 1700 times at the final in the three treatments. The expression of MaACS13 firstly decreased, then increased and decreased during the treatment of ethephon and 1-MCP. In natural maturation, MaACS13 expression changed little in early stage, but decreased significantly at maturity. Based on this result, it was speculated that MaACS10 was a key gene regulating banana maturity.