甜樱桃‘红灯’果实发育过程中AsA积累与相关酶活性变化

AsA Accumulation and Related Enzyme Activities During the Fruit Development in Sweet Cherry‘Hongdeng'

为了解甜樱桃果实抗坏血酸积累的特点及其生理机理,本研究以‘红灯’果实为试验材料,测定其发育过程中抗坏血酸(AsA)含量、谷胱甘肽(GSH)含量及AsA代谢相关酶活性的变化。结果表明:在‘红灯’果实发育过程中,AsA含量在花后0 d最高,之后快速下降再缓慢下降。GSH含量在花后10 d下降,随后迅速上升,在花后20 d达到最大值,后期又下降。AsA、GSH单果积累量发生于其整个发育期,在果实快速生长期积累量最大。果实发育过程中AsA代谢相关酶活性变化有所不同,L-半乳糖脱氢酶(GalDH)活性在整个果实发育期变化不大,抗坏血酸过氧化物酶(APX)活性呈现"降-升-降"的变化趋势;然而,L-半乳糖醛酸内酯酶(GalLDH)、单脱氢抗坏血酸还原酶(MDHAR)、脱氢抗坏血酸还原酶(DHAR)和谷胱甘肽还原酶(GR)的活性与AsA的含量变化趋势基本一致,均在花后0 d活性最高,随后是快速下降期和缓慢下降期。相关性分析表明,GalLDH、MDHAR活性与AsA含量呈极显著相关。本研究对提高甜樱桃抗坏血酸含量具有指导意义。

To understand the characteristics and physiological mechanism of ascorbic acid accumulation during the fruit development of sweet cherry,‘Hongdeng＇was selected as the material in this study and the contents of ascorbic acid（AsA）,glutathione（GSH） and related enzyme activities were determined in the developmental process.The results showed that in the fruit development of ‘Hongdeng＇,the content of AsA was the highest at 0 d after anthesis,and then decreased rapidly first and then decreased slowly.GSH content decreased at 10 d after anthesis,then increased to the maximum at the 20 d,then declined slowly.The accumulations of AsA and GSH increased persistently during the whole fruit growth process of sweet cherry,which was the highest in the fruit rapid growth period.Different enzymes involved in metabolism of AsA showed different variation trend during the development of sweet cherry fruit.For example,L-galactose dehydrogenase（Gal DH） activities kept relatively constant during the whole process,while ascorbic acid peroxidase（APX） presented the variation tendency of＂drops-rises-drops＂.Furthermore,patterns of the activity changes of L-galactono-1-4-lactone dehydrogenase（Gal LDH）,monodehydroascorbate reductase（MDHAR）,dehydroascorbate reductase（DHAR） and glutathione reductase（GR） were similar to that of AsA.They all had the highest activity at 0 d after anthesis and then showed the trend of decreased rapidly and decreased slowly.The correlation analysis proved that activities of Gal LDH and MDHAR had a significantly positive correlation with the content of AsA.The results of this study would provide significant guidance for improving the content of ascorbic acid in sweet cherry.