Research Projects

Rice (Oryza sativa L.), a staple crop feeding nearly two-thirds of the global population, is highly sensitive to environmental stresses. Salinity and drought are major abiotic stresses that limit crop growth and threaten global food security. Also, drought situations in saline soils presents an altogether different challenge to crop productivity, therefore enhancing its resilience becomes a key research priority. While domestication has weakened stress tolerance traits in modern crops, wild relatives serve as valuable genetic reservoirs for stress resilience. Understanding the molecular and physiological mechanisms of stress tolerance in wild rice could aid in breeding climate-resilient, high-yielding varieties. Despite numerous comparative studies on salt and drought stress responses in contrasting plant species, the signaling mechanisms underlying salinity (S) and drought (D) and co-occurring salinity and drought (SD) stress remain poorly understood. It is well established that reactive species, including reactive oxygen species (ROS) and reactive nitrogen species (RNS), function as key signaling molecules that regulate plant development and mediate stress adaptation. Maintaining ROS and RNS at basal, non-cytotoxic levels is critical for plant survival under both optimal and stress conditions. Notably, while wild genotypes do not possess entirely unique traits absent in crops, they exhibit complementary characteristics that confer natural stress tolerance. However, the knowledge of ROS and RNS signaling and its homeostasis in naturally stress-tolerant wild species remains highly limited. A detailed investigation of redox biology at the tissue- and single-cell levels in wild and cultivated rice varieties is still needed. This project aims to address this gap by examining tissue-specific redox dynamics in root tissues and individual stomatal guard cells of rice under S, D and SD. As the primary interface for salt and drought exposure, roots exhibit species- and stress-dependent responses. Meanwhile, plants must osmotically adjust to maintain turgor pressure and regulate stomatal CO₂ assimilation. To achieve this, we will employ cutting-edge approaches to examine how ROS and RNS signaling influence ion transport across cellular membranes in roots and guard cells of wild (Pokkali and P. coaractata) and cultivated (IR29 and IR64) genotypes. Additionally, we will investigate the temporal accumulation of ROS and RNS in various root tissues of rice under S, D and SD, exploring their role in stress perception and tolerance in wild rice species. Furthermore, we will investigate the role of reactive species in regulating water and gas exchange through stomata. Through single-cell transcriptomics, we aim to identify key genes that regulate redox homeostasis in root and stomatal guard cell and these insights will be utilized to "rewild" rice cultivars, enhancing their salinity and drought tolerance for improved resilience in changing climates.