MECHANISMS OF ACTION AND SIGNALING PATHWAYS INVOLVED IN ABIOTIC STRESS ELICITATION

Abiotic stressors like drought, salinity, heat, heavy metals, oxidative stress, and UV radiation severely limit plant growth, development, and productivity. Plants detect these stresses using particular membrane sensors, resulting in fast changes in intracellular calcium concentrations, reactive oxygen species pulses, and phytohormone signaling. These initial signals are converted into conserved kinase signaling pathways (MAPKs, CDPKs, SnRK2s) and hormone-mediated pathways (ABA-dependent and ABA-independent), which then activate stress-responsive transcription factors (DREBs, NACs, WRKYs, MYBs) and remodel the transcriptome. Chromatin modification, alternative splicing, short RNAs, and post-translational modifications (phosphorylation and ubiquitination) all contribute to complicated regulation, ensuring precise control of stress gene expression. Plants use hormonal interactions and network hubs to balance survival, growth, and defense. Recent advances in systems biology have revealed these complicated networks, and biotechnological approaches—transgenic methods, CRISPR/Cas genome editing, and multi-omics integration—have opened up new avenues for the production of stress-tolerant crops. This chapter provides a thorough, human-crafted overview of these processes and examines future directions for applying molecular knowledge to sustainable farming operations.