DROUGHT STRESS IN Brassica napus: PHYSIOLOGICAL RESPONSES, MOLECULAR MECHANISMS, AND INTEGRATED MANAGEMENT STRATEGIES - Muhammad Waqas Yonas; Shoaib Zawar; Mudassir Aziz; Khurram Mubeen; Javeed Shabbir Dar; Ahmad Gull; Hammad Yousaf (Journal of Animal and Plant Sciences, 2026)
Drought stress is a major abiotic factor that severely restricts agriculture productivity, particularly in crops of oilseed, such as Brassica napus L. (B. napus). With the progression of change in climate, the frequency, and severity of drought events are increasing, posing additional challenges to crop production. As a result, enhancing drought tolerance in B. napus has become an important focus of current research. This review synthesizes existing knowledge on the morpho-physiological, biochemical, and molecular response of B. napus to drought stress. It highlights key drought induced changes, including reduction in stomatal conductance, alteration in water use efficiency and photosynthesis performance, and disruption in nutrient uptake. In addition, it discusses the accumulation of reactive oxygen species (ROS) and activation of antioxidant defense systems that help plants to cope with the stress conditions. This review further emphasizes the importance of phytohormone signaling, osmotic adjustment, and stress response gene and transcription factors in enhancing plant adaptation to drought conditions. In addition, several agronomic strategies are identified as affective for mitigation drought stress, including optimized sowing practices, exogenous application of PGR and osmolyte, optimized nutrient management, and the use of beneficial microbial inoculants. At the same time, new avenues for developing drought tolerant cultivars through the development in the molecular breeding, such as transgenic approaches, genome editing, and quantitative trait locus (QTL) mapping. Recent advances such as CRISPR/Cas9, high throughput sequencing, and contemporary breeding techniques are enhancing the precision and effectiveness of the B. napus crop improvement initiative. CRISPR/Cas9-based genome editing, in particular, enables the focused discovery, validation, and change of drought-responsive genes and regulatory pathways, allowing for precision modulation of drought-adaptive features. Future research should focus on integrating multi osmotic approaches, functional genomics, gene editing, and climate resilient phenotyping to accelerate the development of drought tolerate B. napus cultivars. Bringing together advances in plant physiology, biotechnology, and agronomic management will be essential for achieving this goal. Overall, this review offers useful insights for researchers, breeders, and policymakers working to sustain crop productivity under drought conditions.
Keywords: journal article; Brassica napus; CRISPR/Cas9; Drought tolerance; Osmotic adjustment; Mitigation approaches