Photoprotection and optimization of sucrose usage contribute to faster recovery of photosynthesis after water deficit at high temperatures in wheat

Abstract

Plants are increasingly exposed to events of elevated temperature and water deficit, which threaten crop productivity. Understanding the ability to rapidly recover from abiotic stress, restoring carbon assimilation and biomass production, is important to unravel crop climate resilience. This study compared the photosynthetic performance of two Triticum aestivum L. cultivars, Sokoll and Paragon, adapted to the climate of Mexico and UK, respectively, exposed to 1-week water deficit and high temperatures, in isolation or combination. Measurements included photosynthetic assimilation rate, stomatal conductance, in vitro activities of Rubisco (EC 4.1.1.39) and invertase (INV, EC 3.2.1.26), antioxidant capacity and chlorophyll a fluorescence. In both genotypes, under elevated temperatures and water deficit (WD38 C), the photosynthetic limitations were mainly due to stomatal restrictions and to a decrease in the electron transport rate. Chlorophyll a fluorescence parameters clearly indicate differences between the two genotypes in the photoprotection when subjected to WD38 C and showed faster recovery of Paragon after stress relief. The activity of the cytosolic invertase (CytINV) under these stress conditions was strongly related to the fast photosynthesis recovery of Paragon. Taken together, the results suggest that optimal sucrose export/utilization and increased photoprotection of the electron transport machinery are important components to limit yield fluctuations due to water shortage and elevated temperatures. | INTRODUCTIONGlobal warming is a serious threat to crop production. Wheat is the world's most harvested crop per area, however, wheat yield is below the average of the other major crops (e.g., maize and rice) being therefore only the second most-produced cereal grain, with 26% of the world share (FAOSTAT, 2017). Around 40% of the global wheat yield

Response of physiological characteristics and grain yield of winter wheat varieties to long-term heat stress at anthesis

“…Previous studies have shown that the photosynthesis of plants recovers fast after the release of thermal stress of 38°C (Correia et al 2021). Our research shows that after removing 10 d of thermal stress, the photosynthesis of plants did not recover but showed a further reduction, especially in heat-sensitive variety.…”

“…Chl fluorescence is used to assess the effects of environmental changes on photosynthesis indirectly. It has been reported that PSII has high thermal sensitivity (Dash and Mohanty 2001, Sharkey 2005, Correia et al 2021, but high temperatures below 40℃ do not seriously affect PSII activity (Allakhverdiev et al 2008). The ratio of variable fluorescence to maximum fluorescence (F v/Fm) determines the maximum quantum efficiency of PSII, while low Fv/Fm under stress indicates damage to the PSII reaction center.…”

Magnesium Foliar Supplementation Increases Grain Yield of Soybean and Maize by Improving Photosynthetic Carbon Metabolism and Antioxidant Metabolism

“…The cropping of soybean occurs during the spring/summer seasons, which in tropical regions corresponds to the months of September–March. While this period is usually hot and rainy in tropical regions, short dry spells occur frequently during soybean cropping [ 51 ], causing a short period of stress due to lack of water and or high temperatures [ 52 ], especially in the phenological stages after flowering, as observed in our study ( Figure 1 ). In the case of maize, its cropping occurs during the autumn/winter seasons (April-August), a period characterized by mild temperatures and a dry climate.…”

Exploring Local Maize Diversity for Increased Agricultural Sustainability: New Insights into Drought Stress Response and Recovery of Guinea-Bissau Landraces

“…However, P0023 and P9838 showed opposing trends in the response of ETo/RC to water stress (Figure 2c), with the electron transport rate per reaction center decreasing in the former and increasing in the latter (p < 0.05), suggesting that the resilience to oxidative stress (absence of RC inactivation) comes together with a lower photochemical activity. Furthermore, in wheat, Correia et al [58] found a strong correlation between these energy fluxes and the antioxidant capacity of leaves under drought stress. Since drought stress causes the loss of photosynthetic reaction centers, the loss of chlorophyll a content detected in all except P0023 plants during S2 was expected.…”