PUNE: Can injury be the beginning and not signal the end? A new study by researchers from Indian Institute of Science Education and Research (IISER) Pune, with others, has identified a key pathway in plants that leads the injured area to reboot biologically and grow new things instead of shutting down.The moment injury is detected, a set of protein regulators activates the cell recycling cum clean-up system called autophagy, which helps regulate reactive oxygen species (ROS) at the wound site. This, in turn, explains the age-old knowledge of why wounded tissues regenerate new roots efficiently, while others fail.“In simple terms, we found that regeneration is not just about growth hormones, it is about managing stress and resetting the cell,” Akansha Ganguly, the first author of the paper and graduate research fellow, department of biology, at IISER Pune, said.She added, “When injury occurs, stress signalling chemicals called ROS ramp up. Too much accumulation of stress is detrimental to survival and must be brought under control. Plants can deploy specific regulators known as plethoras in response to injury, and these factors activate an ancient cellular clean-up system called autophagy, which occurs naturally across most living organisms. Autophagy cleans up damaged cells in the injured region and brings the ROS (stress molecules) down. Once stress levels are managed, this allows stem cells to be activated, which enables healing and organ regeneration.”It is only 15-20 years since scientists started understanding the molecular basis of regeneration in plants. The team realised that researchers did not yet explore how any wounding causes tremendous stress to cells and how it is managed. “We pondered this question for more than five years. Many stress-signalling molecules and autophagy regulators work in plants. Our challenge was to zero in on the specific ones involved in this organ regeneration process,” Ganguly said.But why is stress management in response to wounds so important? “It is necessary for all life,” Kalika Prasad, professor of biology at IISER Pune and corresponding author of the paper, said. “Mechanisms underlying this regulation of stress are of relevance for both plants and animals. Understanding regeneration could improve how crops recover from physical damage, and could also help horticulture industries boost propagation through cuttings,” he added.
