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

CLC Number: 

• S662.5