Improvement of heat stress tolerance in soybean (Glycine max L), by using conventional and molecular tools

Abstract

The soybean is a significant legume crop, providing several vital dietary components. Extreme heat stress negatively affects soybean yield and quality, especially at the germination stage. Continuous change in climatic conditions is threatening the global food supply and food security. Therefore, it is a critical need of time to develop heat-tolerant soybean genotypes. Different molecular techniques have been developed to improve heat stress tolerance in soybean, but until now complete genetic mechanism of soybean is not fully understood. Various molecular methods, like quantitative trait loci (QTL) mapping, genetic engineering, transcription factors (TFs), transcriptome, and clustered regularly interspaced short palindromic repeats (CRISPR), are employed to incorporate heat tolerance in soybean under the extreme conditions of heat stress. These molecular techniques have significantly improved heat stress tolerance in soybean. Besides this, we can also use specific classical breeding approaches and different hormones to reduce the harmful consequences of heat waves on soybean. In future, integrated use of these molecular tools would bring significant results in developing heat tolerance in soybean. In the current review, we have presented a detailed overview of the improvement of heat tolerance in soybean and highlighted future prospective. Further studies are required to investigate different genetic factors governing the heat stress response in soybean. This information would be helpful for future studies focusing on improving heat tolerance in soybean.

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

“…Furthermore, at T4 (35°C/27°C), the CO 2 fixation contributed maximally to Gs as compared to Tr. Moreover, temperature above optimum results in decreased membrane stability and enhanced Tr ( Jianing et al., 2022 ). This reflects that all these processes strongly adhere to and are affected by the temperature as a unit as indicated in Figures 2 , 3 .…”

“…Soybean plants with high tolerance to temperature stress show a high transcript level of GmEF8 with high proline content as compared to plants grown under control conditions (Jianing et al, 2022). The understanding of genetic responses under varying levels of temperature provides a foundation to further understand the temperature response pathway (Jianing et al, 2022). Tariq et al (2022) performed transcriptome analysis of soybean genotypes NARC-1 and Swat-84 under the same conditions within a glass house; however, the detailed genetic analysis in association with physiological, biochemical, and morphological traits is lacking.…”

“…Therefore, plants activate ROS scavenging mechanisms by enhancing the activities of antioxidant enzymes such as peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) ( Rajput et al., 2021 ). Additionally, a high concentration of ROS impairs the structural integrity of the cell membrane, resulting in membrane damage and less water retentively due to more electrolyte leakage ( Jianing et al., 2022 ). With every 0.8°C rise above the mean temperature, soybean yield is projected to decrease by 2.4% ( Djanaguiraman et al., 2019 ).…”

“…The elongation factor (EF) gene GmEF8 enhances protein levels when soybean faces temperature stress and has a protective role via osmotic adjustments ( Zhang et al., 2022 ). Soybean plants with high tolerance to temperature stress show a high transcript level of GmEF8 with high proline content as compared to plants grown under control conditions ( Jianing et al., 2022 ). The understanding of genetic responses under varying levels of temperature provides a foundation to further understand the temperature response pathway ( Jianing et al., 2022 ).…”

“…Soybean plants with high tolerance to temperature stress show a high transcript level of GmEF8 with high proline content as compared to plants grown under control conditions ( Jianing et al., 2022 ). The understanding of genetic responses under varying levels of temperature provides a foundation to further understand the temperature response pathway ( Jianing et al., 2022 ). Tariq et al.…”