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Non‐structural carbohydrates and sugar export in grapevine leaves exposed to different light regimes
Author(s) -
Dayer Silvina,
Murcia Germán,
Prieto Jorge A.,
Durán Martin,
Martínez Liliana,
Píccoli Patricia,
Perez Peña Jorge
Publication year - 2021
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/ppl.13258
Subject(s) - photosynthesis , sugar , biology , sucrose phosphate synthase , botany , sucrose , phloem , starch , horticulture , carbohydrate metabolism , light intensity , vineyard , invertase , sucrose synthase , food science , biochemistry , physics , optics
Light is a main environmental factor that determines leaf microclimate within the vine, as well as its photosynthesis and carbohydrate metabolism. This study aimed to examine the relationships between photosynthesis, carbohydrate metabolism, and the expression of related genes in leaves of grapevine grown under different radiation regimes. During the 2014/2015 growing season, an experiment was conducted on a Malbec vineyard ( Vitis vinifera L.) in which four radiation exposure treatments were established on the leaves: (1) East, (2) West, (3) Sun, and (4) Shade (i.e., reduction in light intensity). Diurnal dynamics of photosynthesis and non‐structural carbohydrates were measured and leaf export rates were calculated. Transcript profiles of leaf sugar transporters ( VvHT1 , VvHT3 , VvSUC27 ), a sucrose phosphate synthase enzyme ( VvSPS ), and invertases ( VvGIN1 , VvCWI ) were also examined. We showed that East and Sun leaves had higher daily photosynthetic and export rates than West leaves, which was mainly explained by the environmental conditions (air and leaf temperature, VPD leaf‐air ) and leaf water status. Shade leaves accumulated less starch and soluble sugars than exposed leaves, which correlated with a higher expression of hexose transporters and invertases. The hypotheses that these sugars in Shade leaves would play a role as signaling molecules and/or have increased sink strength and phloem unloading are discussed. These results allow us to understand the physiological and molecular behavior of leaves exposed to different radiation regimes, which can be used to design appropriate vineyard management practices.