生长素对油桃‘24-30’果实软化和乙烯生物合成的影响

Effect of NAA on fruit softening and ethylene biosynthesis of '24-30' nectarine

【目的】研究‘24-30’油桃果实发育后期及采后萘乙酸处理下果实硬度和乙烯的变化。【方法】以‘24-30’油桃为试材,检验其果实的硬度和乙烯释放量,以及经采后萘乙酸处理下乙烯生物合成基因(ACS1、ACS4、ACO1)和果实软化关键基因(PG1)的表达量。【结果】‘24-30’采前采后过程中果实硬度和乙烯释放量变化均不明显;与对照果实相比,经NAA处理果实的硬度明显下降,乙烯释放量迅速增加,且处理浓度越高,效果越明显。实时定量表达分析表明,经NAA处理果实与对照相比,PG1和ACS1基因的表达明显增加,且处理浓度越高,基因上调表达越明显。NAA处理对ACS4和ACO1的表达没有明显作用。【结论】‘24-30’油桃采前和采后果实一直维持较高硬度是由于乙烯释放量较低。采用萘乙酸处理‘24-30’油桃果实,可以促进‘24-30’油桃ACS1基因的表达和乙烯的释放,进而导致重要细胞壁相关基因PG1表达上升,加速果实软化。

【Objective】Changes of the fruit firmness and ethylene production in the fruit of nectarine‘24-30'during the late development period and the effect of postharvest NAA treatment were studied.【Meth-ods】The fruits of nectarine‘24-30'were used as materials. Fruit firmness and ethylene production aswell as the expression of ethylene biosynthesis genes(ACS1,ACS4,ACO1)and fruit softening relatedgene(PG1)under NAA treatment on the‘24-30'nectarine fruits was measured.【Results】Changes ofthe fruit firmness and ethylene production in the fruit were not obvious during the late development periodand after harvest,while the firmness decreased very greatly and the ethylene production increased rapidlyafter NAA treatment. with the increase of treatment concentration,the effect was more obvious. Real-time quantitative expression analysis showed that the expression of genes(PG1 and ACS1)was upregulat-ed under NAA treatment,which was more obvious under higher treatment concentration. NAA treatmenthad no obvious effect on the expression of genes(ACS4 and ACO1).【Conclusion】The fruits of‘24-30'can maintain high hardness due to the low level of ethylene production during the late development periodand after harvest,while the expression of ACS1 was upregulated under NAA treatment,and with the in-crease of ethylene production,the expression of fruit softening related gene(PG1)was upregulated,which resulted in fruit softening.