BERMÚDEZ, Luisa; DE GODOY, Fabiana; BALDET, Pierre; DEMARCO, Diego; OSORIO, Sonia; QUADRANA, Leandro; ALMEIDA, Juliana; ASIS, Ramón; GIBON, Yves; FERNIE, Alisdair R; ROSSI, Magdalena; CARRARI, Fernando

doi:10.1111/tpj.12418

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Licence d’utilisation du document

BERMÚDEZ, Luisa
Universidade de São Paulo = University of São Paulo [USP]
Instituto Nacional de Tecnología Agropecuaria [INTA]

DE GODOY, Fabiana
Universidade de São Paulo = University of São Paulo [USP]

BALDET, Pierre
Biologie du fruit et pathologie [BFP]

Langue

Article de revue

Ce document a été publié dans

The Plant Journal. 2014, vol. 77, n° 5, p. 676-87

Wiley

Résumé en anglais

Limitations in our understanding about the mechanisms that underlie source-sink assimilate partitioning are increasingly becoming a major hurdle for crop yield enhancement via metabolic engineering. By means of a comprehensive approach, this work reports the functional characterization of a DnaJ chaperone related-protein (named as SPA; sugar partition-affecting) that is involved in assimilate partitioning in tomato plants. SPA protein was found to be targeted to the chloroplast thylakoid membranes. SPA-RNAi tomato plants produced more and heavier fruits compared with controls, thus resulting in a considerable increment in harvest index. The transgenic plants also displayed increased pigment levels and reduced sucrose, glucose and fructose contents in leaves. Detailed metabolic and enzymatic activities analyses showed that sugar phosphate intermediates were increased while the activity of phosphoglucomutase, sugar kinases and invertases was reduced in the photosynthetic organs of the silenced plants. These changes would be anticipated to promote carbon export from foliar tissues. The combined results suggested that the tomato SPA protein plays an important role in plastid metabolism and mediates the source-sink relationships by affecting the rate of carbon translocation to fruits.< Réduire

Mots clés

fruit metabolism

Mots clés en anglais

chloroplast metabolism

small plastidial protein

source-sink partitioning

tomato