Photorespiration and photoprotection of grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) under water stress

Abstract

In order to investigate the photoprotective function of photorespiration in grapevine under water stress, potted grapevines (Vitis vinifera L. cv. Cabernet Sauvignon) were randomly divided into three uniform groups for well-watered [watered every morning to keep the relative water content (RWC) of soil over 70 %], water-stress adapted (droughtadapted at 30 % relative soil water content for 30 days), and water stress without adaptation treatment (water-stressed to 30 % relative soil water content for 3 days). Net assimilation rate (A N ), stomatal conductance (g s ), substomatal CO 2 concentration (C i ), transpiration rate (E), actual photochemical efficiency of PSII (Φ PSII ), and maximum photochemical efficiency of PSII (F v /F m ) were recorded by combining measurements of gas exchange and chlorophyll fluorescence. Gross photorespiration (P r ), photosynthetic electron partitioning (J C /J T ), photochemical quenching coefficient (q P ), and non-photochemical quenching (NPQ) were also calculated. The ratio of net assimilation rate to transpiration rate (A N /E) was used as an indicator of water use efficiency (WUE). A N , apparent P r , Φ PSII , F v /F m , q P , and g s decreased, NPQ increased, and gross P r sustained at a high level under water stress. This suggests that both photorespiration and energy dissipation play important roles in protecting photosynthetic apparatus against photoinhibition. C i in water-stressed plants without adaptation treatment increased, which indicates the leaves suffered a non-stomatal limitation, while the water-stress adaped plants only suffered a stomatal limitation indicated by low C i .

Physiological parameters and protective energy dissipation mechanisms expressed in the leaves of two Vitis vinifera L. genotypes under multiple summer stresses

“…As found also by other authors Medrano et al, 2002Medrano et al, , 2003Guan and Gu, 2009), the significant increase of NPQ found on WS-Sangiovese leaves compared to WSMontepulciano leaves indicates an elevated thermal dissipation of excessive excitation energy in the chloroplasts. On the other hand, NPQ covariate with the de-epoxidation state of the xanthophyll cycle similarly to what previously reported in grapevines (Chaumont et al, 1997;Flexas et al, 2000).…”

“…Regardless of cultivar, the significantly lower values of J c , PSII and ETR found in leaves of stressed-vines are a common responses in grapevine and were reported for different varieties by several authors (Medrano et al, 2003;Guan et al, 2004;Guan and Gu, 2009;Beis and Patakas, 2012).…”

Water restriction and physiological traits in soybean genotypes contrasting for nitrogen fixation drought tolerance

“…Despite decreases in dry nodule weight, stomatal conductance and transpiration rate, the net photosynthetic rate did not differ from plants under water sufficiency. This may be associated with the elevation of photorespiration to preserve the photosynthetic apparatus, acting on dissipation of energy (Guan and Gu, 2009). Moreover, the genotypes R01-581F and R02-1325 showed higher concentration of chlorophyll under drought, whereas the other genotypes had a reduction, negatively affecting the photosynthetic performance (Baker and Rosenqvst, 2004).…”

Near isohydric grapevine cultivar displays higher photosynthetic efficiency and photorespiration rates under drought stress as compared with near anisohydric grapevine cultivar

“…Grapevines ( Vitis vinifera ) grow well in arid and semiarid environments (Cifre et al , Grimplet et al ), in spite of the fact that water limitations increase the hazards of photoinhibition (Lu and Zhang ). Several photoprotective mechanisms, including photorespiration, have been found to increase the sustainability of grapevines in these areas (Guan and Gu , Wang et al ).…”