Effects of Water Stress on Photosynthesis, Yield, and Water Use Efficiency in Winter Wheat

Abstract

Drought has become one of the major constraints to agricultural development, particularly in areas that lack water. Studying the effects of different water stresses on the photosynthesis, growth, yield, water use efficiency (WUE) and irrigation water productivity (IWP) of winter wheat will provide data for the development of scientific irrigation strategies for water-saving agricultural methods. According to the size of the field water capacity, four different water stress levels were set, i.e., 30–40% (severe stress), 40–50% (moderate stress), 50–60% (mild stress) and 60–80% (well-watered) of field water capacity, controlling the amount of irrigation through an automatic irrigation system. The results showed that the seasonal changes in photosynthetic parameters, such as net photosynthetic rate (Pn), intercellular carbon concentration (Ci), stomatal conductance (Gs) and transpiration (E), significantly decreased under moderate and severe stress. As a result, the height, biomass and grain size of winter wheat decreased significantly, which led to low WUE and IWP. The Pn of the mild stress group only slightly decreased compared to that of the well-watered group, and was actually higher during the flowering and grain-filling stages, resulting in increases in dry biomass and 1000 grain weight of 2.07% and 1.95%, respectively. Higher WUE and IWP were attributed to higher yields and less water use. Thus, mild stress (60–80% field water capacity) resulted in the optimal use of water resources without a significant reduction in yield in the North China Plain (NCP). Therefore, mild stress can be considered a suitable environment for winter wheat growth in arid areas.

Responsiveness of Early Response to Dehydration Six-Like Transporter Genes to Water Deficit in Arabidopsis thaliana Leaves

“…is certainly affected by the arrest of cell growth under enhanced dehydration, leading to the drop of cell water potential and the loss of turgidity (Hsiao, 2003;Simonneau et al, 2017;Turner, 2018). Taken together our results agree with the already established concept that the arrest of cell growth responds to a milder water deficit than that required for a photosynthetic rate reduction (dos Santos Gouvêa and Marenco, 2018;Zhao et al, 2020). Consequently, the limitation of carbon assimilation is not the real cause of cell growth arrest.…”

“…In conclusion, Arabidopsis and other plants respond in a similar way to water deficit with a decrease of WC, SC, FW, PLA, and DW and a concomitant increase of sugars and other compatible osmolytes (Mewis et al, 2012;Sperdouli and Moustakas, 2012;dos Santos Gouvêa and Marenco, 2018;Zhao et al, 2020). Although more than 1,000 genes have been identified to be involved in drought response (Seki et al, 2002;Shinozaki and Yamaguchi-Shinozaki, 2007;Lawlor, 2013;Fang and Xiong, 2015), only a few of them have been characterized in terms of induced tolerance to water depletion, combined with enhanced plant productivity in model plants, as well as in important agricultural crops (Skirycz et al, 2011).…”

“…However, this tolerance/survival predicts neither better growth capacity nor the enhancement of productivity. In the last decade, the global vision of research focused on genes, which results in the elevation of biomass and the yield of seeds under the conditions of moderate water stress (Skirycz et al, 2011;Raza et al, 2019;Zhao et al, 2020). To cope up with water deficit, plants have developed different strategies such as escape, avoidance, and osmotic adjustment strategies (Arve et al, 2011;Fang and Xiong, 2015;Ilyas et al, 2020).…”

“…Under mild and moderate water deficit (MD), SC decreases, but a partial closure of stomata does not prevent photosynthesis activity. However, the efficiency of photosynthesis is reduced under more severe water stress (Lawlor, 2002;Lawlor and Cornic, 2002;Muller et al, 2011;Zhao et al, 2020).…”

Integration of Gas Exchange With Metabolomics: High-Throughput Phenotyping Methods for Screening Biostimulant-Elicited Beneficial Responses to Short-Term Water Deficit

“…WUE is a largely diffused performance indicator for crop yield and water consumption. Water-stressed plants typically exhibit a higher WUE due to a more conservative use of water, resulting in improved resource utilization efficiency under conditions of water scarcity (Zhao et al, 2020). Nevertheless, high stomatal conductance over time is essential to high plant production, translating into maximized soil water-use for transpiration, or effective use of water (EUW) for transpiration.…”