Molecular Plant Breeding 2025, Vol.16, No.1, 63-72 http://genbreedpublisher.com/index.php/mpb 69 The development and adoption of drought-tolerant soybean varieties also face socioeconomic and regulatory challenges. The acceptance of genetically modified (GM) crops varies across regions, and regulatory frameworks can impact the commercialization of biotechnologically enhanced varieties (Pathan et al., 2007; Manavalan et al., 2009). Additionally, the cost of developing and deploying new drought-tolerant varieties can be a barrier for resource-limited farmers. Addressing these challenges requires a collaborative effort between researchers, policymakers, and stakeholders to create supportive policies and ensure equitable access to improved soybean varieties (Pathan et al., 2007; Manavalan et al., 2009; Dubey et al., 2019). In conclusion, the integration of marker-assisted selection, conventional breeding, and biotechnological approaches holds great promise for developing drought-tolerant soybean varieties. However, overcoming environmental variability and addressing socioeconomic and regulatory challenges are essential to fully realize the potential of these advancements. Future research should focus on refining breeding strategies, enhancing our understanding of drought tolerance mechanisms, and fostering an enabling environment for the adoption of resilient soybean cultivars. 7 Concluding Remarks The study on drought tolerance mechanisms in soybean seed germination has yielded significant insights from both physiological and molecular perspectives. Genome-wide association studies (GWAS) identified several single nucleotide polymorphisms (SNPs) and candidate genes associated with drought tolerance during the germination stage. For instance, 26 SNPs were identified across 10 chromosomes, leading to the discovery of 41 candidate genes related to drought tolerance. Another study identified 15 SNPs associated with drought tolerance indices, with some SNPs located near previously mapped QTLs. Different soybean cultivars exhibit varied physiological responses to drought stress. For example, cultivar PI31 showed superior drought and salinity stress tolerance mechanisms, including enhanced photosynthesis, osmolyte accumulation, and antioxidative enzyme activity. Transcriptome analyses revealed numerous differentially expressed genes (DEGs) involved in drought response, including those related to water and auxin transport, antioxidant activity, and secondary metabolism. Additionally, metabolomics studies highlighted the role of osmotic compound accumulation and enhanced energy and secondary antioxidant metabolism in drought-tolerant wild soybean. The role of microRNAs (miRNAs) in regulating drought tolerance was elucidated, with gma-miR398c identified as a negative regulator of drought tolerance through its impact on peroxisome-related genes. These findings underscore the complex interplay of genetic, physiological, and molecular factors in conferring drought tolerance in soybean seed germination. Future research should focus on several key areas to further enhance our understanding and application of drought tolerance mechanisms in soybean. One crucial area is the functional validation of candidate genes. Conducting functional studies to validate the roles of identified candidate genes and SNPs in drought tolerance will be essential. This could involve the use of gene editing techniques such as CRISPR to create drought-tolerant soybean varieties. Another important focus should be the integration of multi-omics approaches. Utilizing integrative multi-omics approaches, which combine genomics, transcriptomics, proteomics, and metabolomics, will provide a comprehensive understanding of the molecular networks involved in drought tolerance. This holistic view is crucial for identifying key regulatory pathways and potential targets for genetic improvement. Breeding programs must be developed and implemented to incorporate identified genetic markers and candidate genes into the production of drought-tolerant soybean cultivars. Marker-assisted selection and genomic-assisted selection should be key components of these programs, ensuring that the most promising genetic traits are effectively utilized. Additionally, it is important to investigate the interactions between drought tolerance mechanisms and other environmental stress factors, such as salinity and temperature. Understanding these interactions will enable the development of soybean varieties that can withstand multiple stress conditions, ultimately enhancing the resilience and productivity of soybean crops in diverse and challenging environments. The insights gained from this study have significant implications for soybean production and global food security. By understanding and leveraging the genetic and molecular mechanisms of drought tolerance, it is possible to develop soybean varieties that are more resilient to drought conditions, thereby ensuring stable yields even in
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