摘要：

探讨欧李果实发育成熟过程中钙摄取与吲哚乙酸(IAA)及有机酸代谢的关系,为欧李的进一步研究和应用提供依据。以内蒙古地区高钙和低钙2种钙素水平欧李果实为试验材料,研究果实发育成熟过程中(幼果期、硬核期、着色膨大期、硬熟期、完熟期)果实钙摄取能力及IAA和有机酸代谢的变化规律,并进行相关性分析。结果表明,水溶钙的摄取能力在欧李果实发育成熟过程中持续增强,尤其在完熟期时摄取活性、摄取速率和摄取量均大幅上升;果胶钙的摄取能力在幼果期至硬核期较强,果实发育中后期摄取能力下降,至完熟期时摄取活性、摄取速率和摄取量均显著下降;活性钙和总钙的摄取能力变化规律均趋向于与果胶钙相似。在果实发育成熟过程中,2种钙素水平欧李果实中的IAA含量表现为先升高后降低,幼果期和硬核期含量显著高于其他时期。苹果酸脱氢酶(NAD-MDH)活性、苹果酸含量和有机酸总量均整体表现为明显上升,硬熟期达到最高;苹果酸酶(NADP-ME)活性整体表现为下降;柠檬酸含量均表现为先升高后降低,硬核期达到最高。相关性分析表明,高钙和低钙欧李果实中IAA含量及有机酸代谢各指标与不同形态钙摄取能力各指标之间存在不同程度的相关性,其中IAA含量与总钙的摄取能力呈正相关;NAD-MDH活性、苹果酸含量和有机酸总量与总钙的摄取能力呈负相关;NADP-ME活性和柠檬酸含量与总钙的摄取能力呈正相关。欧李果实发育成熟过程中钙摄取与IAA含量和有机酸代谢有关,果实发育前期高水平的IAA和柠檬酸含量对钙的摄取有明显促进作用;果实发育后期苹果酸合成代谢增强对钙的摄取有抑制作用。

关键词: 欧李, 钙摄取, 吲哚乙酸, 有机酸代谢

Abstract:

The aim of this study was to investigate the relationship between calcium uptake,indoleacetic acid(IAA)and organic acid metabolism during the development and ripening of Cerasus humilis fruits,in order to provide a basis for further research and applications of Cerasus humilis.The high calcium and low calcium Cerasus humilis fruits from Inner Mongolia were taken as the experimental materials.Samples were taken at different stages of fruit development and ripening,including the young fruit stage(S1),hard kernel stage(S2),coloring and enlargement stage(S3),hard ripening stage(S4),and fully ripe stage(S5),this study investigated the changes of calcium uptake capacity,IAA,and organic acid metabolism,and carried out correlation analysis.The results indicated that the uptake capacity of water-soluble calcium continuously increased throughout the development and ripening of Cerasus humilis fruits,with a marked rise in uptake activity,uptake rate,and uptake amount at the fully ripe stage;the uptake capacity of calcium pectin was higher from the young fruit stage to hard kernel stage but declined in the later stages of fruit development,with a significant reduction in uptake activity,uptake rate,and uptake amount at the fully ripe stage;the uptake capacity for active calcium and total calcium followed trends similar to those observed for calcium pectin.During fruit development and ripening,the IAA content in Cerasus humilis fruits showed a pattern of initially increasing and then decreasing,with significantly higher levels during the the young fruit stage and hard kernel stage compared to other stages.The activity of NAD-MDH,as well as malic acid content and organic acid total content,generally increased,peaking at the hard ripening stage.The activity of NADP-ME declined overall,while citric acid content increased initially and then decreased,reaching its highest point at the hard kernel stage.Correlation analysis revealed varying degrees of correlation between IAA content,organic acid metabolism indicators,and the uptake capacity of different calcium forms in high-calcium and low-calcium Cerasus humilis fruits.Specifically,IAA content was positively correlated with the uptake capacity of total calcium;the activity of NAD-MDH,malic acid content,and organic acid total content was negatively correlated with total calcium uptake capacity;while the activity of NADP-ME and citric acid content was positively correlated with total calcium uptake capacity.During the development and ripening of Cerasus humilis fruits,calcium uptake is associated with IAA content and organic acid metabolism.High levels of IAA and citric acid contents during the early stages of fruit development significantly promote calcium uptake,whereas enhanced malic acid synthesis and metabolism in the later stages of fruit development inhibits calcium uptake.

Key words: Cerasus humilis, Calcium uptake, IAA, Organic acids metabolism

中图分类号: 

• S662.5