Open AccessBeyond the limits of photoperception: constitutively active PHYTOCHROME B2 overexpression as a means of improving fruit nutritional quality in tomato
Author(s) -
Alves Frederico Rocha Rodrigues,
Lira Bruno Silvestre,
Pikart Filipe Christian,
Monteiro Scarlet Santos,
Furlan Cláudia Maria,
Purgatto Eduardo,
Pascoal Grazieli Benedetti,
Andrade Sónia Cristina da Silva,
Demarco Diego,
Rossi Magdalena,
Freschi Luciano
Publication year - 2020
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.13362
Subject(s) - biology , chloroplast , carotenoid , sugar , phytochrome , plastid , biofortification , chlorophyll , mutant , wild type , antioxidant , botany , biochemistry , micronutrient , gene , chemistry , organic chemistry , red light
Summary 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.