Reactive oxygen species (ROS, partial reduction or derivatives of free radicals) are highly reactive, dangerous and can cause oxidative cell death. In addition to their role as toxic by-products of aerobic metabolism, ROS play a role in the control and regulation of biological processes such as growth, the cell cycle, programmed cell death, hormone signaling, biotic and abiotic stress reactions and development. ROS always arise in plants as a by-product of several metabolic processes that are located in different cell compartments, or as a result of the inevitable escape of electrons to oxygen from the electron transport activities of chloroplasts, mitochondria and plasma membranes. These reactive species are formed in chloroplasts, mitochondria, plasma membranes, peroxisomes, apoplasts, the endoplasmic reticulum and cell walls. The action of many non-enzymatic and enzymatic antioxidants present in tissues is required for efficient scavenging of ROS generated during various environmental stressors. The current review provides an in-depth look at the fate of ROS in plants, a beneficial role in managing stress and other irregularities. The production sites are also explained with their negative effects. In addition, the biochemical properties and sources of ROS generation, capture systems, the influence of ROS on cell biochemistry and the crosstalk of ROS with other signaling molecules/pathways are discussed.

A milestone was set in the field of medicine with the discovery of L-asparaginase present in the serum of guinea pig responsible for action against the acute lymphoblastic leukemia. Since then, the use of L-asparaginase as a potential anti-cancer drug has been a great success in the field of modern oncology. Despite its varied sources, new sources are continuously being explored to obtain a high therapeutic index drug. The study aims to isolate potential L-asparaginase producing microorganisms from environmental niches of Northwestern Himalayas. The climatic conditions of the region and ancient agricultural practices which are still being followed in these areas, add up to the diverse microbial repository and a potential habitat which can be explored to obtain a potent asparaginase producing microbial source. In the study, soil samples from different regions of Jammu were collected aseptically. From the isolation studies, a total of 44 bacterial isolates were obtained. Pure cultures were then screened for asparaginase activity both qualitatively as well as quantitatively using agar plate and nesselerization method. Screening studies resulted in the isolation of a potent L-asparaginase producer isolated from black gram soil sample of Rajouri, Jammu showing an enzyme activity of 9.14 U/ml. Based on biochemical and molecular approaches, the isolate was identified as Enterobacter aesburiae strain R16C1 / No. MT93543. The study resulted in the isolation of a pure bacterial culture from the soils of Northwestern Himalayas possessing anti-cancer asparaginase activity. Further, optimization studies can help in considerably increasing the enzyme activity which can be tested against different human cancer lines for its anti-cancer efficacy.