Beyond the limits of photoperception: constitutively active PHYTOCHROME B2 overexpression as a means of improving fruit nutritional quality in tomato

Author(s):Show less -

Rodrigues Alves, Frederico Rocha ^{[1, 2]} ; Lira, Bruno Silvestre ^[1] ; Pikart, Filipe Christian ^[1] ; Monteiro, Scarlet Santos ^[1] ; Furlan, Claudia Maria ^[1] ; Purgatto, Eduardo ^[3] ; Pascoal, Grazieli Benedetti ^{[3, 4]} ; Silva Andrade, Sonia Cristina ^[5] ; Demarco, Diego ^[1] ; Rossi, Magdalena ^[1] ; Freschi, Luciano ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Bot, Sao Paulo, SP - Brazil

^[2] Univ Fed Goias, Dept Bot, Goias, Go - Brazil

^[3] Univ Sao Paulo, Dept Alimentos & Nutr Expt, Sao Paulo, SP - Brazil

^[4] Univ Fed Uberlandia, Curso Grad Nutr, Uberlandia, MG - Brazil

^[5] Univ Sao Paulo, Dept Genet & Biol Evolut, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Plant Biotechnology Journal; v. 18, n. 10 APR 2020.
• Web of Science Citations: 3

Abstract

Photoreceptor engineering has recently emerged as a means for improving agronomically beneficial traits in crop species. Despite the central role played by the red/far-red photoreceptor phytochromes (PHYs) in controlling fruit physiology, the applicability of PHY engineering for increasing fleshy fruit nutritional content remains poorly exploited. In this study, we demonstrated that the fruit-specific overexpression of a constitutively active GAF domain Tyr(252)-to-His PHYB2 mutant version (PHYB2(Y252H)) significantly enhances the accumulation of multiple health-promoting antioxidants in tomato fruits, without negative collateral consequences on vegetative development. Compared with the native PHYB2 overexpression, PHYB2(Y252H)-overexpressing lines exhibited more extensive increments in transcript abundance of genes associated with fruit plastid development, chlorophyll biosynthesis and metabolic pathways responsible for the accumulation of antioxidant compounds. Accordingly, PHYB2(Y252H)-overexpressing fruits developed more chloroplasts containing voluminous grana at the green stage and overaccumulated carotenoids, tocopherols, flavonoids and ascorbate in ripe fruits compared with both wild-type and PHYB2-overexpressing lines. The impacts of PHYB2 or PHYB2(Y252H) overexpression on fruit primary metabolism were limited to a slight promotion in lipid biosynthesis and reduction in sugar accumulation. Altogether, these findings indicate that mutation-based adjustments in PHY properties represent a valuable photobiotechnological tool for tomato biofortification, highlighting the potential of photoreceptor engineering for improving quality traits in fleshy fruits. (AU)

• FAPESP's process: 16/01128-9 - Light and hormonal regulation of nutritional quality in Solanum lycopersicum
• Grantee: Maria Magdalena Rossi
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 16/04924-0 - Manipulating phytochrome levels in tomato fruits (Solanum lycopersicum L.) and its impacts on plastid development, physiology and nutritional composition
• Grantee: Frederico Rocha Rodrigues Alves
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/25774-2 - Overexpression of hyperactive mutant forms of phytochromes B1 and B2 as a means of manipulating tomato quality traits
• Grantee: Scarlet Santos Monteiro
• Support type: Scholarships in Brazil - Master
• FAPESP's process: 18/16389-8 - Manipulation of light signaling and nitric oxide metabolism as a means of improving tomato quality traits
• Grantee: Luciano Freschi
• Support type: Regular Research Grants