Effects of high night temperature on soybean yield and compositions

Abstract

IntroductionSoybean is sensitive to light and temperature. Under the background of global asymmetric climate warming.MethodsThe increase of night temperature may have an important impact on soybean yield. In this study, three varieties with different level of protein were planted under 18°C and 28°C night temperatures for investigating the effects of high night temperatures on soybean yield formation and the dynamic changes of non-structural carbohydrates (NSC) during the seed filling period (R5-R7).Results and discussionThe results indicated that high night temperatures resulted in smaller seed size, lower seed weight, and a reduced number of effective pods and seeds per plant, and thus, a significant reduction in yield per plant. Analysis of the seed composition variations showed carbohydrates were more substantially affected by high night temperature than protein and oil. We observed “carbon hunger” caused by high night temperature increased photosynthesis and sucrose accumulation in the leaves during the early stage of high night temperature treatment. With elongated treated time, the excessive carbon consumption led to the decrease of sucrose accumulation in soybean seeds. Transcriptome analysis of leaves after 7 days of treatment showed that the expression of most sucrose synthase and sucrose phosphatase genes decreased significantly under the high night temperature. Which could be another important reason for the decrease of sucrose. These findings provided a theoretical basis for enhancing the tolerance of soybean to high night temperature.

Optimization of soybean physiochemical, agronomic, and genetic responses under varying regimes of day and night temperatures

“…The agronomic yield varies corresponding to physiological yield at changing regimes of day and night temperatures. Consistent with these studies, the current study reported a complete parallelism between the variation in physiological and biochemical traits below and beyond the optimum temperature T4 (35°C/27°C) (Figures 1-3), which was in accordance with the results of Alsajri et al (2019); Yang et al (2023), andChoi et al (2016). Additionally, the paired association of physiological, biochemical, and agronomic traits varies not only with changing regimes of temperatures but also with the nature of the cultivar used.…”

“…Although a rise in temperature impacts adversely the soybean reproductive phase and seed formation, the effect of temperature changes varies with extent, the period, and cultivars ( Djanaguiraman et al., 2019 ). It has been projected that soybean production decreased by 17% with every 1°C rise in temperature above optimum in soybean-growing regions ( Yang et al., 2023 ). In addition, the rise of temperature above optimum significantly decreases agronomic yield such as pods per plant, seed size, seed number, and seed yield in soybeans ( Choi et al, 2016 ).…”

The role of crop simulation modeling in assessing potential climate change impacts

“…While nighttime temperature may not be high enough to reduce pollen germination, it can still increase respiration rates, resulting in decreased grain biomass accumulation. This has been shown to occur in rice (Bahuguna et al, 2017) and soybean (Yang et al, 2023). Most models account for temperature effects on respiration, mainly via relationships between biomass and respiration rate.…”

“…Increased temperatures are also expected to increase efflux of carbon from soils because of increased respiration and reduction of soil water (Nissan et al., 2023). There is evidence (Cox et al., 2020) that nighttime temperatures are increasing faster than daytime, so the diurnal temperature differentials are higher and this differential can be more important than the temperatures themselves (Yang et al., 2023). While nighttime temperature may not be high enough to reduce pollen germination, it can still increase respiration rates, resulting in decreased grain biomass accumulation.…”

Tropical nights in the Mediterranean: A spatiotemporal analysis of trends from 1950 to 2022

“…This is attributed to the fact that minimum air temperatures modulate night‐time plant respiration rates, potentially reducing biomass accumulation and crop yields (Hatfield & Prueger, 2015; Kumudini et al, 2014; Sadok & Jagadish, 2020). For instance, night temperature plays an important role in soybean protein and oil accumulation, and high night temperatures result in a significant reduction in yield due to smaller seed size, lower seed weight and a reduced number of effective pods and seeds per plant (Song et al, 2016; Yang et al, 2023). Wheat, which is one of the leading agricultural products in the world, is most adversely affected by even short episodes of high night temperatures during the grain‐filling period, resulting in a significantly reduced yield (Mamrutha et al, 2020).…”