Heat Stress in Indian Mustard (Brassica juncea L.): A Critical Review of Impacts and Adaptation Strategies

Indian mustard, a member of the Brassicaceae family, is a cool-season crop cultivated extensively in various agro-ecological conditions, contributing significantly to vegetable oilseed production. However, being a thermosensitive and C3 plant [1], Indian mustard is highly susceptible to high-temperature stress, particularly during critical developmental stages [2]. High temperatures disrupt physiological, morphological, and biochemical mechanisms essential for plant growth and development. From altered chlorophyll content and osmotic water potential to impaired photosynthesis and reduced seed oil accumulation, heat stress detrimentally affects various aspects of Indian mustard physiology. This comprehensive review examines the impacts of heat stress on Indian mustard, a significant oilseed crop, and explores adaptation strategies to mitigate its adverse effects. Additionally, heat stress during reproductive stages leads to flower abortion, reduced fertility, and poor seed development, significantly impacting yield potential. To cope with heat stress, plant response mechanisms involve intricate signaling pathways, leading to cellular readjustments at transcriptome, epigenome, proteome, and metabolome levels. Breeding approaches, including conventional techniques and advanced molecular tools like CRISPR/Cas-based genome editing, offer promising avenues for developing heat-tolerant cultivars. Integration of multi-omics approaches aids in identifying stress-responsive genes and metabolic pathways crucial for adaptation. Agronomic strategies, such as nutrient management and microbial inoculation, play vital roles in mitigating heat stress effects and enhancing plant resilience. Collaborative efforts and interdisciplinary research are essential to deepen our understanding of heat stress responses and develop sustainable solutions to ensure oilseed crop productivity and food security in the face of climate change. This review underscores the urgency of addressing heat stress challenges in Indian mustard cultivation and highlights the need for concerted efforts to develop effective adaptation strategies for sustainable agriculture.