caa a22 4500 606208151 CHVBK 20210128101021.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s00425-015-2329-x doi (NATIONALLICENCE)springer-10.1007/s00425-015-2329-x Identification and functional characterization of grapevine transporters that mediate glucose-6-phosphate uptake into plastids [Elektronische Daten] [Henrique Noronha, Carlos Conde, Serge Delrot, Hernâni Gerós] Main conclusion : Two grapevine glucose-6-Pi plastidial transporters differently expressed in plant organs and in response to environmental and hormonal signals are characterized. They are involved in starch accumulation in berries and canes. In grapevine, starch accumulation in the trunk is important for winter storage of carbon and in the flower for reproductive development. Berries also accumulate starch in their plastids, which are also involved in the synthesis of aroma compounds important for fruit quality. The present work characterizes two glucose-phosphate translocators (VvGPT1, VvGPT2) that control the accumulation of starch in grape amyloplasts. Three different splicing variants identified for VvGPT2 (VvGPT2α, VvGPT2β and VvGPT2Ω) were more expressed in the leaves than in other organs. In contrast, VvGPT1 transcripts were more abundant in mature berries, canes and flowers than in the leaves. Expression of 35S-VvGPT1-GFP and 35S-VvGPT2Ω-GFP in tobacco leaf epidermal cells showed that the fusion proteins localized at the plastidial envelope. Complementation of the Arabidopsis pgi1-1 mutant impaired in leaf starch synthesis restored its ability to synthesize starch, demonstrating that VvGPT1 and VvGPT2Ω mediate the transport of glucose-6-Pi across the plastidial envelope. In grape cell suspensions, ABA, light and galactinol, together with sucrose and fructose, significantly increased the transcript abundance of VvGPT1, whereas VvGPT2Ω expression was affected only by sucrose. In addition, elicitation with methyl jasmonate strongly upregulated VvGPT1, VvGPT2Ω and VvPAL1, suggesting a role for GPTs in the production of secondary compounds in grapevine. Moreover, in grapevines cultivated in field conditions, VvGPT1 expression was higher in berries more exposed to the sun and subjected to higher temperatures. Although both VvGPT1 and VvGPT2 mediate the same function at the molecular level, they exhibit different expression levels and regulation in plant organs and in response to environmental and hormonal signals. Springer-Verlag Berlin Heidelberg, 2015 Amyloplast nationallicence Glucose-6-phosphate translocators (VvGPT1, VvGPT2) nationallicence Starch nationallicence Sugar transporter nationallicence Vitis nationallicence E (W) : East (West) exposed grape clusters nationallicence GFP : Green fluorescent protein nationallicence GPT : Glucose-6-phosphate/phosphate translocator nationallicence MeJA : Methyl jasmonate nationallicence pPT : Plastidial phosphate translocators nationallicence RDI : Regulated deficit irrigation nationallicence SDI : Sustained deficit irrigation nationallicence TPT : Triose-phosphate/phosphate translocator nationallicence Noronha Henrique Centro de Investigação e de Tecnologias Agro-ambientais e Biológicas CITAB, Vila Real, Portugal aut Conde Carlos Instituto de Biologia Molecular e Celular IBMC, Universidade do Porto, Porto, Portugal aut Delrot Serge INRA, ISVV, Ecophysiologie et Génomique Fonctionnelle de la Vigne, UMR 1287, Université de Bordeaux, Villenave D'Ornon, France aut Gerós Hernâni Centro de Investigação e de Tecnologias Agro-ambientais e Biológicas CITAB, Vila Real, Portugal aut Planta Springer Berlin Heidelberg 242/4(2015-10-01), 909-920 0032-0935 242:4<909 2015 242 425 https://doi.org/10.1007/s00425-015-2329-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00425-015-2329-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Noronha Henrique Centro de Investigação e de Tecnologias Agro-ambientais e Biológicas CITAB, Vila Real, Portugal aut NATIONALLICENCE 700 1- Conde Carlos Instituto de Biologia Molecular e Celular IBMC, Universidade do Porto, Porto, Portugal aut NATIONALLICENCE 700 1- Delrot Serge INRA, ISVV, Ecophysiologie et Génomique Fonctionnelle de la Vigne, UMR 1287, Université de Bordeaux, Villenave D'Ornon, France aut NATIONALLICENCE 700 1- Gerós Hernâni Centro de Investigação e de Tecnologias Agro-ambientais e Biológicas CITAB, Vila Real, Portugal aut NATIONALLICENCE 773 0- Planta Springer Berlin Heidelberg 242/4(2015-10-01), 909-920 0032-0935 242:4<909 2015 242 425