TY - JOUR
T1 - Near isohydric grapevine cultivar displays higher photosynthetic efficiency and photorespiration rates under drought stress as compared with near anisohydric grapevine cultivar
AU - Hochberg, Uri
AU - Degu, Asfaw
AU - Fait, Aaron
AU - Rachmilevitch, Shimon
PY - 2013/4/1
Y1 - 2013/4/1
N2 - Drought stress is known to limit photosynthesis rates and to inflict photo-oxidative damage in grapevines. Grapevines, which are considered drought-tolerant plants, are characterized by diverse hydraulic and photosynthetic behaviors, depending on the cultivar. This research compared the photosynthesis and the photorespiration of Cabernet Sauvignon (Cs) (isohydric) and Shiraz (anisohydric) in an attempt to acquire a wider perspective on the iso/anisohydric phenomenon and its implications. Shiraz and Cs were subjected to terminal drought in the greenhouse. Soil water content (θ), leaf water potential (Ψl) and stomata conductance (gs) were measured to determine the cultivars' hydraulic behavior. Gas exchange and fluorometry measurements were taken at 21 and 2% O2 to acquire photosynthesis and photorespiration characteristics. Cs was found to behave in a near isohydric manner whereas Shiraz behaved in a near anisohydric manner. Compared to Shiraz, the reduced stomata conductance values of Cs were accompanied by higher water use efficiency and photorespiration rates, as well as photosystem II photochemical potential (Fv/Fm). As compared with Shiraz, Cs compensated for lower stomata conductance by higher photosynthesis and photorespiration. These two processes contributed to higher electron flow rates that might have a role in photoinhibition avoidance, which was observed in the stability of Fv/Fm under drought stress.
AB - Drought stress is known to limit photosynthesis rates and to inflict photo-oxidative damage in grapevines. Grapevines, which are considered drought-tolerant plants, are characterized by diverse hydraulic and photosynthetic behaviors, depending on the cultivar. This research compared the photosynthesis and the photorespiration of Cabernet Sauvignon (Cs) (isohydric) and Shiraz (anisohydric) in an attempt to acquire a wider perspective on the iso/anisohydric phenomenon and its implications. Shiraz and Cs were subjected to terminal drought in the greenhouse. Soil water content (θ), leaf water potential (Ψl) and stomata conductance (gs) were measured to determine the cultivars' hydraulic behavior. Gas exchange and fluorometry measurements were taken at 21 and 2% O2 to acquire photosynthesis and photorespiration characteristics. Cs was found to behave in a near isohydric manner whereas Shiraz behaved in a near anisohydric manner. Compared to Shiraz, the reduced stomata conductance values of Cs were accompanied by higher water use efficiency and photorespiration rates, as well as photosystem II photochemical potential (Fv/Fm). As compared with Shiraz, Cs compensated for lower stomata conductance by higher photosynthesis and photorespiration. These two processes contributed to higher electron flow rates that might have a role in photoinhibition avoidance, which was observed in the stability of Fv/Fm under drought stress.
UR - http://www.scopus.com/inward/record.url?scp=84874967481&partnerID=8YFLogxK
U2 - 10.1111/j.1399-3054.2012.01671.x
DO - 10.1111/j.1399-3054.2012.01671.x
M3 - Article
C2 - 22901023
SN - 0031-9317
VL - 147
SP - 443
EP - 452
JO - Physiologia Plantarum
JF - Physiologia Plantarum
IS - 4
ER -