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A putative role for TIP and PIP aquaporins in dynamics of leaf hydraulic and stomatal conductances in grapevine under water stress and re‐watering
Author(s) -
POU ALICIA,
MEDRANO HIPOLITO,
FLEXAS JAUME,
TYERMAN STEPHEN D.
Publication year - 2013
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12019
Subject(s) - aquaporin , petiole (insect anatomy) , chemistry , vitis vinifera , stomatal conductance , xylem , botany , drought stress , biophysics , water transport , transpiration , horticulture , biochemistry , biology , photosynthesis , water flow , hymenoptera , environmental engineering , engineering
We examined the role of aquaporins (AQPs) in regulating leaf hydraulic conductance ( K leaf ) in Vitis vinifera L. (cv Chardonnay) by studying effects of AQP inhibitors, and AQP gene expression during water stress (WS) and recovery (REC). K leaf was measured after 3 h of petiole perfusion with different solutions and to introduce inhibitors. The addition of 0.1 m m HgCl 2 to 15 m m KCl reduced K leaf compared with perfusion in 15 mM KNO 3 or KCl, and these solutions were used for leaves from control, WS and REC plants. Perfusion for 3 h did not significantly alter stomatal conductance ( g s ) though expression of VvTIP1;1 was increased. WS decreased K leaf by about 30% and was correlated with g s . The expression of VvTIP2;1 and VvPIP2;1 correlated with K leaf , and VvTIP2;1 was highly correlated with g s . There was no association between the expression of particular AQPs during WS and REC and inhibition of K leaf by HgCl 2 ; however, HgCl 2 treatment itself increased expression of VvPIP2;3 and decreased expression of VvPIP2;1 . Inhibition by HgCl 2 of K leaf only at early stages of WS and then after REC suggested that apoplasmic pathways become more important during WS. This was confirmed using fluorescent dyes confined to apoplasm or preferentially accumulated in symplasm.