ABSTRACT
Several chemical substances are necessary for the growth and development of agricultural crop plants. Stress signals regulate an intricate network of transporters and metabolic activities in plants. Ca2+, nucleic acids, sugars and polyphosphoinositides, NO, ABA, jasmonic acids, salicylic acids, and polyamines are all examples of signal transduction molecules. A rise in Ca2+ levels is common when a crop plant is stressed because this is the typical secondary messenger in signal transduction pathways. Ca2+ sensors activate several receptors and pass them through the signaling chain to detect the presence of Ca2+ signals. Mitogen-activated protein kinases (MAPKs) may be triggered by hormones, hormone-like substances, environmental variables, and other stimuli. Phosphatidylinositols play an important role in intracellular signaling and plasma membranes. NO, a plant growth regulator, activates a variety of defense genes. Glycolysis, photosynthesis, nitrogen metabolism, such as reactive oxygen species and starch metabolization, defense systems, and cell cycle regulation are all dependent on sugar. ABA, JA, SA, and polyamines impact a wide range of stress responses. It is common for plants to respond against abiotic challenges through chemical signaling pathways. Crop plants are susceptible to abiotic stress, which may produce a wide range of signaling molecules. Abiotic stress response in agricultural crop plants is regulated by hormone signaling molecules, summarized in this chapter.
