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Author Massot, Capucine ♦ Stevens, Rebecca ♦ Génard, Michel ♦ Longuenesse, Jean Jacques ♦ Gautier, Hélène
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©2011
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Life sciences; biology
Subject Keyword Biosynthesis ♦ Gene expression ♦ Light ♦ Solanum ♦ Tomato ♦ Vitamin C ♦ Forestry ♦ Ecology ♦ Agriculture ♦ Plant Sciences
Abstract Little is known about the light regulation of vitamin C synthesis in fruits. In contrast, previous studies in leaves revealed that VTC2 (coding for GDP-l-galactose phosphorylase) was one of the key genes up-regulated by light in leaves. Our objective was to determine how the expression of ascorbate (AsA) synthesis genes in tomato (Solanum lycopersicum) was modified according to light irradiance in both leaves and fruits. Seven days of shading strongly decreased total ascorbate (reduced and oxidized form) content in leaves (50%) and to a lesser extent in fruits (10%). Among the last six steps of AsA biosynthesis, only two genes, VTC2 and GPP1 (one of the two unigenes coding for l-galactose-1-P phosphatase in tomato), were down-regulated by long-term shading in red ripe fruits, compared to seven genes regulated in leaves. This underlines that light affects AsA-related gene expression more in leaves than in ripening fruits. Moreover, this study reveals strong daily changes in transcript levels of enzymes of the AsA biosynthetic pathway in leaves (11 of the 12 studied genes showed significant changes in their expression pattern). Among those genes, we found that diurnal variation in transcript levels of VTC2 and GME1 correlated to leaf AsA content measured 8 h later. This study provides a new hypothesis on the role of GME1 in addition to VTC2 in light-regulated AsA biosynthesis.
ISSN 00320935
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2011-08-23
Publisher Place Berlin/Heidelberg
e-ISSN 14322048
Journal Planta
Volume Number 235
Issue Number 1
Page Count 11
Starting Page 153
Ending Page 163

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Source: SpringerLink