Adaptive Roles of Plant Hormones in Regulating Flowering Time Under Changing Climate Conditions

Abstract

Climate change has profoundly influenced plant growth and reproductive development, particularly the regulation of flowering time, which is vital for crop yield and ecosystem stability. Fluctuating temperatures, altered photoperiods, drought, and elevated atmospheric CO₂ levels disrupt the environmental cues that synchronize flowering with favorable growth conditions. Plant hormones—such as gibberellins (GAs), abscisic acid (ABA), auxins, cytokinins, ethylene, jasmonic acid (JA), and salicylic acid (SA)—serve as central regulators in translating these environmental signals into adaptive physiological responses. Through intricate signaling networks and hormonal cross-talk, they modulate the timing and progression of flowering to ensure reproductive success under stress. Gibberellins generally promote floral initiation, while ABA often acts antagonistically under drought and heat stress, delaying flowering to conserve resources. Similarly, cytokinins, auxins, and ethylene coordinate floral meristem development and organ differentiation, maintaining reproductive balance. Climate-induced stress alters hormone biosynthesis, signaling, and degradation, leading to shifts in flowering phenology. Understanding these hormone-mediated adaptive mechanisms is crucial for breeding and engineering climate-resilient crops capable of sustaining yield under unpredictable environmental conditions. Moreover, integrating hormonal regulation insights into climate-smart agriculture—through genetic modification, marker-assisted breeding, and exogenous hormone application—offers new pathways for sustainable crop management. Hence, elucidating the adaptive hormonal control of flowering time provides a foundation for enhancing agricultural resilience and food security in the face of accelerating climate change.