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The soybean is a source of several dietary components, including milk, protein, and oil. Cold stress has significantly curtailed soybean growth and yield in large areas and caused a high risk to global food security. The main objective of soybean breeders is to improve soybean resistance to cold stress. Conventional breeding approaches have made significant progress in developing cold tolerance in soybean; however, the high cost and complex genetic mechanism of cold tolerance hindered the large scale of these techniques. Molecular tools like quantitative trait loci (QTL), genome-wide association studies (GWAS), transcription factors (TFs), genetic engineering, and transcriptome have been used to identify cold tolerant genes/QTL and to develop soybean cultivars tolerant to cold stress. Clustered, regularly interspaced short palindromic repeats (CRISPR/Cas9) is used to increase the abiotic stress tolerance in soybean; however, its use to edit the cold tolerance genes in soybean is limited. Mapping of QTL has accelerated the master-assisted selection (MAS) in soybean. This review presents a detailed overview of molecular techniques and their use in developing cold-tolerant soybean cultivars. Using CRISPR/Cas9 would increase the speed of molecular breeding for cold tolerance in soybean. This information will assist soybean researchers in uncovering the basis of cold stress tolerance in soybean and adopting the most suitable way to breed the cold tolerant cultivars which can thrive under the extreme pressure of cold stress.

Abiotic stresses and climate changes cause severe loss of yield and quality of crops and reduce the production area worldwide. Flooding stress curtails soybean growth, yield, and quality and ultimately threatens the global food supply chain. Flooding tolerance is a multigenic trait. Tremendous research in molecular breeding explored the potential genomic regions governing flood tolerance in soybean. The most robust way to develop flooding tolerance in soybean is by using molecular methods, including quantitative trait loci (QTL) mapping, identification of transcriptomes, transcription factor analysis, CRISPR/Cas9, and to some extent, genome-wide association studies (GWAS), and multi-omics techniques. These powerful molecular tools have deepened our knowledge about the molecular mechanism of flooding stress tolerance. Besides all this, using conventional breeding methods (hybridization, introduction, and backcrossing) and other agronomic practices is also helpful in combating the rising flooding threats to the soybean crop. The current review aims to summarize recent advancements in breeding flood-tolerant soybean, mainly by using molecular and conventional tools and their prospects. This updated picture will be a treasure trove for future researchers to comprehend the foundation of flooding tolerance in soybean and cover the given research gaps to develop tolerant soybean cultivars able to sustain growth under extreme climatic changes.

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.

An azo chromophore molecular S(-)-1,2-bis(4-azophenyl-4-nitro)-ethylenediamine (OABANEDA) was synthesized with 4-nitroaniline and S(-)-1,2-diphenyl ethylenediamine by diazo-coupling reaction. The azo polyurethane-urea (OAAPUU) was obtained from OABANEDA, polyether diol (NJ-210) and isophorone diisocyanate (IPDI). The structure of OAAPUU was characterized by the Fourier transform infrared and UV-visible spectroscopy. The physical and mechanical properties of OAAPUU were investigated. The refractive index ( n) and transmission loss of OAAPUU film were measured at different temperatures and different laser wavelengths (532 nm, 650 nm and 850 nm) by an attenuated total reflection (ATR) technique and CCD digital imaging devices. A Y-branch and Mach-Zehnder interferometer (MZI-type) switches based on thermo-optic effect of OAAPUU film were designed and simulated. The result showed that the power consumption of the Y-branch switch and the MZI-type switch could be only 0.52 mW and 1 mW, while the response times of the two types switches reach about 0.2 ms and 0.01 ms, respectively. [ABSTRACT FROM AUTHOR]