@article{HUANG2026, 
author = {MengChi HUANG and LiNa CHEN and DengTao GAO and Li LIU and JingYi HAN and ShuYun DUAN and ZhaoNing LIU and HaoXian LI and ZhenHua LU},
title = {Analysis of Sugar and Organic Acid Components and Related Metabolic Gene Expression During Fruit Development in 14 Blueberry Cultivars},
year = {2026},
journal = {Scientia Agricultura Sinica},
volume = {59},
number = {13},
pages = {2919-2932},
keywords = {blueberry, soluble sugar, maturity stage, metabolism-related gene, oganic acid},
url = {https://www.sciopen.com/article/10.3864/j.issn.0578-1752.2026.13.013},
doi = {10.3864/j.issn.0578-1752.2026.13.013},
abstract = {ObjectiveTo characterize the dynamic changes in sugar and organic acid composition across three key developmental stages in 14 major blueberry cultivars currently cultivated in China, which differ markedly in ripening period and flavor profile, and to elucidate the relationship between PEPC and organic acid metabolism in blueberry fruit, thereby providing theoretical support for blueberry production and flavor quality improvement.MethodFruits of 14 blueberry cultivars at three key ripening stages (green, pink, and blue) were used as materials. Soluble sugar and organic acid components were determined by HPLC, and the expression patterns of the PEPC gene were analyzed by qRT-PCR.ResultDuring fruit ripening, the accumulation dynamics of TA and TSS varied among different blueberry cultivars and could be classified into three acid-accumulation patterns (continuous decline, stable-decline, and increase-decline) and three sugar-accumulation patterns (continuous increase, stable-increase, and decline-increase). Glucose and fructose were the major soluble sugar components in blueberry fruits, whereas citric acid, quinic acid, and malic acid were the predominant organic acids. Among them, quinic acid exhibited a relatively high coefficient of variation. Cluster analysis based on sugar and organic acid composition divided the 14 cultivars into four groups. In four cultivars, the major organic acids were citric acid, quinic acid, and malic acid; seven cultivars were dominated by citric acid and malic acid; and one cultivar was characterized primarily by citric acid and quinic acid. In these 12 cultivars, the proportions of glucose and fructose were relatively balanced. In contrast, the remaining two cultivars showed a clear predominance of quinic acid, with fructose content significantly higher than that of glucose. Total sugar content in blueberry fruits was significantly positively correlated with glucose and fructose contents, while total organic acid content was extremely significantly positively correlated with the contents of citric acid, quinic acid, oxalic acid, and lactic acid. In the three blueberry cultivars representing different acid-accumulation patterns, PEPC expression increased from the green fruit stage to the pink fruit stage, but was downregulated from the pink fruit stage to the blue fruit stage. During this latter period, the contents of malic acid and citric acid in the fruits also decreased correspondingly.ConclusionDuring blueberry fruit development, the variation patterns of TA and TSS were closely associated with cultivar characteristics. The major soluble sugar components were glucose and fructose, while the predominant organic acids were citric acid, quinic acid, and malic acid. Based on organic acid composition, the cultivars could be categorized into two types: high-citric-acid and high-quinic-acid types. In three blueberry cultivars representing different acid-accumulation patterns, PEPC expression was downregulated from the pink fruit stage to the blue fruit stage, which was consistent with the declining trends of malic acid and citric acid contents, indicating that PEPC is involved in the metabolism of organic acids in blueberry fruits.}
}