Combined Analysis of Transcriptome and Metabolome Explains the Differences in Pulp Color in Jackfruit

Area of Science:

• Plant Biochemistry
• Molecular Biology
• Agricultural Science

Background:

• Jackfruit (Artocarpus heterophyllus) pulp color is a key trait influencing consumer preference and nutritional value.
• Understanding the genetic and metabolic underpinnings of pulp coloration is crucial for jackfruit breeding and quality improvement.

Purpose of the Study:

• To elucidate the molecular mechanisms responsible for the distinct pulp colors in different jackfruit cultivars.
• To identify key flavonoid and carotenoid compounds and their associated genes contributing to jackfruit pulp coloration.

Main Methods:

• Integrated transcriptomic and metabolomic analyses were performed on three jackfruit cultivars with varying pulp colors (light yellow, yellow, orange).
• Differential accumulation of flavonoids and carotenoids was quantified, and gene expression patterns related to their biosynthesis pathways were analyzed.

Main Results:

• Twenty-five differentially accumulated flavonoids and 32 differentially accumulated carotenoids were identified across the cultivars.
• Specific compounds like naringenin chalcone, eriodictyol, taxifolin, zeaxanthin, and lutein were linked to light-yellow pulp, while phlorizin and lutein were associated with yellow pulp.
• Apigenin, luteolin, zeaxanthin, and violaxanthin dipalmitate were identified as key pigments for orange pulp.
• Differential expression of genes including PAL, C4H, 4CL, F3H, FLS, ANS, ANR, PSY, PDS, ZDS, LCYE, LUT5, ZEP, and VDE was observed in relation to pigment biosynthesis.

Conclusions:

• This study provides a comprehensive molecular and metabolic basis for jackfruit pulp coloration.
• The identified key pigments and differentially expressed genes offer valuable targets for marker-assisted selection in jackfruit breeding programs aimed at controlling pulp color.