Integrated metabolomic and transcriptomic analysis reveals factors underlying differences in fruit quality between Fragaria nilgerrensis and Fragaria pentaphylla

BACKGROUND: Strawberries have become one of the most popular fruits because of their unique flavor and high nutritional value. Fruit quality and price are the most important criteria that determine consumer acceptability. Fragaria nilgerrensis and Fragaria pentaphylla are two wild Asian diploid strawberry species that differ in fruit color, taste, and aroma. To understand the molecular mechanisms involved in the formation of high-quality strawberry fruit, we integrated transcriptomics and metabolomics research methods to compare the metabolic and biosynthetic mechanisms of the two Fragaria species. RESULTS: F. nilgerrensis fruit has higher amino acid and lipid contents and a higher sugar-to-acid ratio than F. pentaphylla fruit does, underlying their superior nutritional value, aroma, firmness, and taste. Compared with F. nilgerrensis fruit, F. pentaphylla fruit contained more flavonoids, indicating its enhanced color and health benefits. In addition, candidate structural genes that regulate the biosynthesis of flavonoids, amino acids, and glycerophospholipids in the two strawberry fruit were screened. CONCLUSIONS: The differences in aroma, firmness, and taste between F. nilgerrensis fruit and F. pentaphylla fruit are probably due to differences in their amino acid and lipid contents, as well as the difference in their sugar-to-acid ratios. Eight key structural genes that may play important roles in the biosynthesis of amino acids, lipids, and flavonoids were identified. © 2021 Society of Chemical Industry.