Starch is a key storage carbohydrate in plants whose metabolism is regulated by various factors, including light. Transitory starch is synthesised during the day and metabolised at night to support plant growth. Previous studies have indicated that the red/far-red light photoreceptor phytochrome A (phyA) influences transitory starch metabolism in tomato. In this study, we examined starch levels in the phyB1 mutant of tomato under light and dark conditions, along with the expression of genes involved in starch synthesis and degradation. Compared to its isogenic wild-type, the phyB1 mutant accumulates significantly less transitory starch under both sunlight and monochromatic red-light. RT-qPCR analysis revealed reduced expression of key starch metabolism genes in the phyB1 mutant. These findings suggest that loss of phyB1 activity reduces transitory starch abundance in tomato by modulating the expression of genes in the starch metabolic pathway.
Amphibians are among the most threatened vertebrate groups globally, with population declines driven by habitat destruction, climate change, emerging diseases, and environmental pollution. Among anthropogenic pollutants, nitrogen-based fertilizers, particularly urea, have emerged as significant ecological stressors affecting amphibian survival, growth, development, and reproduction. At the same time, urea also functions as a vital endogenous metabolite involved in osmoregulation, cryoprotection, nitrogen recycling, ammonia detoxification, and metabolic suppression in several amphibian species. This systematic review synthesizes current knowledge regarding the dual role of urea in amphibian biology, integrating evidence from toxicological, physiological, developmental, and ecological studies. The reviewed literature demonstrates that environmental exposure to urea can induce behavioural abnormalities, embryotoxicity, developmental retardation, oxidative stress, hematological alterations, and mortality in amphibians. Embryonic and larval stages are particularly sensitive to nitrogen pollution, frequently exhibiting edema, deformities, delayed metamorphosis, and reduced survival. Conversely, endogenous urea production contributes substantially to physiological adaptation during hibernation, freezing tolerance, terrestrial development, and metabolic dormancy. Recent studies further reveal the importance of gut microbial ureolysis and urea-mediated cryoprotection in enhancing amphibian resilience under environmental stress. The review highlights the paradoxical nature of urea as both a toxic environmental contaminant and an adaptive physiological molecule. Understanding this duality is essential for amphibian conservation, environmental monitoring, and sustainable fertilizer management in ecologically sensitive habitats.
Enzymes serve as biological catalysts that participate in a critical task detoxifying reactive oxygen species and breaking down toxic pollutants. Microbial enzymes from microalgae, macroalgae and bacteria hold potential promise and significance for biodegradation applications. Enzymes such as lipases, alkane monooxygenases, esterases, and dehydrogenases are associated with driving crude oil degradation. This study examines the biochemical effects of petroleum hydrocarbons from crude oil, sludge from tank bottom, and Effluent Treatment Plant (ETP) hydrocarbon sludge on enzyme activities of algae species. These pollutants contain mostly aliphatic compounds like butane, propane, and aromatic compounds like benzene, cyclohexane, which are toxic and carcinogenic in nature. Algal cultures were exposed to these pollutants at a pre-determined 9 mg/mL minimal inhibition concentration for 28 days, and the activities of lipase, esterase, dehydrogenase, and catalase were evaluated. Esterase activity increased by 4.00%–56.00% in cultures incubated consisting treatment compared to controls, which are algae cultures without any treatment, while catalase activity remained unchanged. Dehydrogenase and lipase activities showed minor variations, with Euglena sp. displaying 65.00% more lipase activity in cultures having treatment. GC-FID investigation of crude oil, sludge from tank bottom, and Effluent Treatment Plant (ETP) hydrocarbon sludge revealed hydrocarbon compounds ranging from Carbon 1 to 30 with propane predominating more than 90% of Total petroleum hydrocarbons (TPH). TPH abatement was found out to be 99.99% TPH in crude oil on treatment with Euglena sp. and Chlamydomonas sp., and 72.00% degradation by Chlorella sp. In ETP sludge, 99.00% TPH degradation was observed across three algae species, while sludge treatment achieved 99.90% degradation with Chlamydomonas sp. and Chlorosarcinopsis sp. These obtained results clearly allude to these algae species being capable degraders of petroleum hydrocarbons illustrating GC-FID’s functioning in remediation processes as an analyzing tool.
