Bolstering Wheat's Immunity: BABA-Mediated Defense Priming Against Bipolaris sorokiniana Amid Competition

Abstract

Plants encounter numerous biotic and abiotic challenges, with biotic stresses significantly limiting wheat productivity. Competition for nutrients and space among plants adds another layer of stress. Defense priming is a promising approach to enhancing plant protection against these environmental stresses. This study explores BABA ({beta}-aminobutyric acid) priming in wheat against Bipolaris sorokiniana under varying degrees of competition. We assessed growth parameters, disease phenotype, biochemical changes, and yield-related traits in both primed and non-primed wheat under disease pressure and competition. Our findings revealed that growth parameters declined in both primed and non-primed wheat as competition increased. However, primed wheat showed better morphological growth than non-primed wheat at each competition level. Under disease pressure, primed wheat demonstrated protection comparable to non-challenged plants at all competition levels, while non-primed plants were susceptible. Non-primed wheat under high-density (HD) conditions exhibited the highest disease susceptibility due to intense competition. BABA-primed plants showed better disease protection at each competition level compared to non-primed plants. BABA priming allowed plants to mitigate competition effects and maintain a consistent defense response. The yield performance of primed wheat was superior to that of non-primed wheat across all competition levels. Our research suggests BABA priming as an effective pesticide-free strategy for crop protection against pathogens under competitive conditions.