Harnessing Endophytes for the Management of Brown Spot of Rice Incited by Bipolaris oryzae

Abstract

Brown spot of rice represents a globally important disease of rice, capable of inflicting severe yield losses under epidemic conditions. The historical relevance of this pathogen is exemplified by its major role in the Bengal Famine of 1943, highlighting its potential to cause large-scale crop failures which can be a threat to food security. Conventional disease management practices, including resistant varieties, use of disease-free seeds, hot water treatment, and chemical fungicides, remain the primary control measures. However, rising concerns over environmental impacts and the emergence of fungicide-resistant pathogen strains highlight the urgent need for sustainable alternatives. Endophytes, the beneficial microbes residing asymptomatically within plant tissues have emerged as promising bio control agents. They enhance plant health through nutrient acquisition, hormone modulation, and suppression of pathogens via multiple antagonistic mechanisms. They exhibit efficient root colonization, metabolic diversity, and competitive exclusion of pathogens, making them ideal for integrated disease management. Various studies have demonstrated the potential of endophytic strains in mitigating brown spot severity while promoting plant growth. Their eco-friendly nature and multifaceted interactions with the host make them effective tools for reducing chemical inputs in agriculture. This review explores the biology and epidemiology of brown spot disease, the current management strategies, and highlights the emerging role of endophytes in disease suppression and plant resilience. It also discusses future directions, including the application of multi-omics technology and genetic engineering to enhance the efficacy of endophytes. Overcoming regulatory hurdles and conducting large-scale field trials will be critical for transitioning from lab to field. Harnessing endophytes offers a sustainable, innovative pathway to combat brown spot of rice, reduce fungicide dependency, and build climate-resilient agricultural systems.