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Reactive oxygen species (ROS) generation within a cell is a natural process of certain sub-cellular components involved in redox reactions. Within a plant cell, chloroplasts are one of the major roofs for ROS generation. Plastid generated ROS molecules involve singlet oxygen (1 O2 ), superoxide radical (O2 - ), hydroxyl radical (OH• ) and hydrogen peroxide (H2 O2 ) which are produced mainly during photochemical reactions of photosynthesis and chlorophyll biosynthetic process. Under normal growth and developmental process, generated ROS molecules act as a secondary messenger controlling several metabolic reactions, however perturbed environmental conditions lead to multifold amplification of cellular ROS that eventually drags the target cell to death. To maintain the homeostasis between production and scavenging of ROS, the cell has instituted several enzymatic and non-enzymatic anti-oxidant machineries to bring ROS at the physiological level. Among chloroplastic ROS molecules, excessive generation of singlet oxygen (1 O2 ) is highly deleterious to the cells metabolic functions and in turn survival. Interestingly, within cellular antioxidant machinery, the enzymes involved in detoxification of 1 O2 are lacking. Recent studies suggest that under optimal concentration 1 O2 acts as a signaling molecule and drive the cell to either acclimation pathway or regulated cell death (RCD). Stress-induced RCD is one of the survival mechanisms for the whole plant and involvement of chloroplasts and chloroplasts localized molecules that execute RCD are not well understood. Through this review, we intend to advocate the participation of chloroplasts-generated 1 O2 in signaling and RCD in plants.

Cyanobacteria are ubiquitously distributed oxygenic photosynthetic prokaryotes, present even in extreme environments. Many cyanobacteria have been found to be excellent sources of proteins and bioa...

The context-specific, complex issue of ‘vaccine hesitancy’ is explicated in terms of delay or refusal of vaccination despite the availability of vaccine services. Although eleven million beneficiaries were administered the COVID-19 vaccine in India from 16th January 2021 till 20th February 2021, however, proportionately a low turnout has been registered in various parts of the country, possibly attributable to hesitance/apprehension towards the current vaccination. In this backdrop, we report the response (collected between Feb 1, 2021 and Feb 15, 2021) of 358 voluntary respondents who participated in an online questionnaire-based pan-India survey, executed to assess their knowledge and acceptance towards the current COVID-19 vaccination program in its first phase. The survey questionnaire consisted of demographic characteristics of the respondents and queries pertaining to knowledge (7 items) and acceptance (3 items). The overall correct rate and the average knowledge score of the participants were 78 % and 5.46 ± 1.4/7 respectively. The acceptance score was 3.50 ± 1.6/5 while 70 % of participants agreed against the 20 % of respondents who neither agreed nor disagreed to take the vaccine. Around 66 % believed that the vaccines, currently being administered in India are safe. Fear about possible side effects (44 %) and inadequacy of comprehensive clinical trial data (29 %), seemed to be the major players in fortifying the vaccine hesitancy among the respondents, exhibiting negative acceptance. Although maximum respondents demonstrated a good level of knowledge (82%) and acceptance (88%), significant differences were observed among some demographic variables. In general, a positive correlation was observed between knowledge and acceptance against a negative correlation, observed in specific provinces. Despite the good acceptance and knowledge, a considerable fraction of the participants (30%) expressed hesitancy. Counselling, mobilization, and feedback from vaccinated individuals about safety should be encouraged. However, due to the limited sample size, we must be cautious when generalizing these findings. Nevertheless, the major elucidations of this study may be utilized in planning vaccination campaigns in further phases.

Parkinson's disease (PD) is one of the most common neurodegenerative disorders with limited clinical interventions. A number of epidemiological as well as case-control studies have revealed an association between pesticide exposure, especially of paraquat (PQ) and occurrence of PD. Hsp70, a molecular chaperone by function, has been shown as one of the modulators of neurological disorders. However, paucity of information regarding the protective role of Hsp70 on PQ-induced PD like symptoms led us to hypothesize that modulation of hsp70 expression in the dopaminergic neurons would improve the health of these cells. We took advantage of Drosophila, which is a well-established model for neurological research and also possesses genetic tools for easy manipulation of gene expression with limited ethical concern. Over-expression of hsp70 was found to reduce PQ-induced oxidative stress along with JNK and caspase-3 mediated dopaminergic neuronal cell death in exposed organism. Further, anti-apoptotic effect of hsp70 was shown to confer better homeostasis in the dopaminergic neurons of PQ-exposed organism as evidenced by their improved locomotor performance and survival. The study has merit in the context of human concern since we observed protection of dopaminergic neurons in PQ-exposed organism by over-expressing a human homologue of hsp70, HSPA1L, in these cells. The effect was parallel to that observed with Drosophila hsp70. These findings reflect the potential therapeutic applicability of hsp70 against PQ-induced PD like symptoms in an organism.