Metabolomic and transcriptomic analyses reveal new insights into the role of abscisic acid in modulating mango fruit ripening

Abstract

Mango (Mangifera indica L.) is a climacteric tropical fruit consumed around the world. Although ethylene and abscisic acid (ABA) have been considered to be stimulators that trigger mango fruit ripening, their regulation mechanisms in modulating mango fruit ripening remain uncertain. In this study, we performed integrative analyses of metabolome and transcriptome data combined with a series of physiology and experiment analysis on ‘Keitt’ mango, and we characterized changes in specific metabolite accumulation at different stages during mango fruit development and ripening, which were strongly correlated with transcriptional changes and embodied the physiological changes as well as taste formation. Specifically, we found that ABA, rather than ethylene, was highly associated with mango ripening, and exogenous ABA application promoted mango fruit ripening. Transcriptomic analysis identified diverse ripening-related genes involved in sugar and carotenoid biosynthesis and softening-related metabolic processes. Furthermore, networks of ABA and ripening-related genes (such as MiHY5, MiGBF4, MiABI5 and MibZIP9) were constructed, and the direct regulation of the key ABA responsive transcription factor MiHY5 to ripening-related genes were experimentally confirmed by ranges of evidence. Taken together, our results indicate that ABA plays a key role in directly modulating mango fruit ripening through MiHY5, suggesting the need for a re-conceiving about how we understand ABA function in modulating climacteric fruit ripening.

Involvement of Transcription Factors and Regulatory Proteins in the Regulation of Carotenoid Accumulation in Plants and Algae

“…In recent years, numerous transcription factors, including MYB, bHLH, MADS, bZIP, NAC, AP2/ERF, and GLK families, have been identified to regulate the carotenoid biosynthesis pathway in higher plants. − In particular, with the development of sequencing and omics technologies, through the correlation between gene expression and phenotype of plants at different developmental stages and varieties, especially flowering plants, relevant transcription factors can be discovered that may regulate the metabolism of carotenoids or determine changes in the accumulation of carotenoids in the process of flower/leaf color change or fruit ripening. − …”

Abscisic acid biosynthesis, metabolism and signaling in ripening fruit

“…In sweet orange, ABA levels peak in the colored stage in both Navelate and Pinalate cultivars ( Romero and Lafuente, 2020 ). During the ripening of mango fruit, the ABA content gradually increases with changes in total soluble solids (TSS), firmness and color ( Wu et al., 2022a ). In tomato fruit, ABA content also increases and reaeches its peak at breaker stage ( Wang et al., 2021 ).…”

Correlation Between Molecular Markers and Sweetness and Peel Thickness of Mango (Mangifera indica L.)

“…The sweetness of mango fruit is determined by the concentration of sugars, such as fructose and glucose, in the fruit 4,17,18 . The genetic basis of fruit sweetness in mango is complex and involves multiple genes 19 . Some of the genes that have been implicated in the regulation of mango fruit sweetness include the MADS-box transcription factor gene, MdMDBF1, which has been shown to regulate sugar metabolism in mango fruit and other genes involved in the biosynthesis and transport of sugars 19 .…”