Second Messengers: Central Regulators in Plant Abiotic Stress Response

Plants differ from animals by lacking the ability to escape from their environmental conditions. Plants adapt to the seasonal as well as nonseasonal perturbations by means of stress-responsive genes. Manipulation of such genes has been shown to provide abiotic stress tolerance in plants. Since abiotic stress is a polygenic trait, overexpression of single stress-responsive gene would not serve the purpose of getting stress-tolerant plants. So, the focus needs to be shifted towards the “master regulators” which are critical for plant growth and development and play an important role in integrating various stress signals and controlling downstream stress responses by modulating gene expression machinery. In plants, there are various second messengers including calcium, ROS, phosphoinositides, cyclic nucleotides, etc., which are known to initiate the downstream signaling cascade leading to response against different, multiple, and simultaneous ambient cues. A better understanding of these elements will allow us to engineer a particular stress-responsive pathway, to achieve better stress-tolerant plants.