Combined effect of elevated temperature and drought stress on carbohydrate metabolism of cotton (Gossypium hirsutum L.) subtending leaves

Abstract

High temperatures and drought are expected to become more frequent in the future and last longer than ever before. To investigate their combined effect on leaves subtending cotton boll (LSCB), an experiment was conducted from 2016 to 2018 using a nonheat‐tolerant cotton cultivar and a heat‐tolerant cultivar. Two temperature regimes with ambient temperature (AT, 31.0/26.4°C) and elevated temperature (ET, 33.4/28.9°C, 2.5°C higher than AT) and three drought treatments with a soil relative water content (SRWC) of 75 ± 5%, 60 ± 5%, and 45 ± 5% were established repeatedly. ET decreased net photosynthetic rate (Pn), initial rubisco activity (4.1.1.39, RuBP) and cytosolicfructose‐1,6‐bisphosphatase (cy‐FBPase; 3.1.3.11) activity, upregulated GhSuSyA, and GhSuSyD expressions, and increased SuSy (2.4.1.13) activity, which led to the decline of the final starch and sucrose contents. Moreover, RuBP, Pn, and starch content all decreased with drop in SRWC levels, but the cy‐FBPase and SPS (2.4.1.14) activity increased, which in turn increased sucrose content. Under combined stresses, when the changing trends of ET and drought effects were the same, the decrease of Pn, RuBP, and starch content was greater than under single stress exposure. However, when the changing trends of ET and drought effects were adverse, the combined effects on indicators such as cy‐FBPase, SuSy, sucrose content were mostly similar to drought stress. These results indicate that the effect of drought on carbohydrate metabolism in LSCB is more prominent than ET. Thus, the drought effect for carbohydrate metabolism in LSCB may need more attention than ET under combined heat and drought stress.

Straw mulching combined with phosphorus fertilization increased photosynthesis rate and grain yield of wheat due to reduced stomatal and mesophyll limitations

“…Our results showed that soil P deficiency increased the activities of SPS and sucrose synthase activity, improving sucrose content in flag leaves (Figure 4). During grain filling, sucrose stored in the stems and leaves is mobilized, enabling sucrose to move from vegetative organs to grains (Hu et al., 2023). The reduction in soluble sugar content may be due to adaptation to soil P deficiency.…”

Nighttime Warming Reduced Copper Concentration and Accumulation in Wheat Grown in Copper-Contaminated Soil by Affecting Physiological Traits

“…Moreover, at this stage, warming treatments afforded a higher total biomass of wheat compared to no-warming treatments, which was probably because a higher temperature increment at the reproductive stage increased post-flowering photosynthesis by promoting the net photosynthesis rate (Figure 4B), which had a greater effect on wheat substance accumulation than metabolism and promoted wheat growth, especially grain filling [48,49]. And to some extent, the increase in carbohydrates was a response of plants to temperature stress [50]. At the maturation stage, except for the fact that wheat in WT-Cu exhibited higher leaf biomass and significant influence compared to other treatments, the biomass of almost every tissue was higher by no-warming applications than that by warming applications.…”

Salt-induced changes in the photosynthetic apparatus and carbon metabolism of two tomato cultivars with varying salt tolerance

“…The enzymes were extracted according to the method by Hu et al (2023). In brief, 1.0 g of the fresh leaves were ground in a pre-cooled mortar containing 10 mL of hydroxyethyl piperazine ethane sulfonic acid (HEPES) buffer (50 mM HEPES pH = 7.5, 1 mM EDTA, 10 mM MgCl 2 , 2.5 mM dithiothreitol, 10 mM vitamin C, and 5% insoluble polyvinyl pyrrolidone).…”