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•Due to thermomorphogenesis, down-regulation of Phytochrome B, carbon nanoparticle induced a Shade Avoidance Response-like scenario.•Concurrently, carbon nanoparticle altered the ABA pathway and stomatal distribution with size.•Carbon nanoparticle acted as hydroscopic binders to hold more water in cells of carbon nanoparticle-treated plants.•Carbon nanoparticle treatment could exert cold stress tolerance in seedlings stage and water stress tolerance in reproduction stage in rice.•Carbon nanoparticle treatment increased yield in rice plants by maintaining better WUE, improving water-relation parameters.

Tuberculosis represents a significant public health crisis. There is an urgent need for novel molecular scaffolds against this pathogen. We screened a small library of marine-derived compounds against shikimate kinase from Mycobacterium tuberculosis(MtSK), a promising target for antitubercular drug development. Six manzamines previously shown to be active against M. tuberculosiswere characterized as MtSK inhibitors: manzamine A (1), 8-hydroxymanzamine A (2), manzamine E (3), manzamine F (4), 6-deoxymanzamine X (5), and 6-cyclohexamidomanzamine A (6). All six showed mixed noncompetitive inhibition of MtSK. The lowest KIvalues were obtained for 6across all MtSK–substrate complexes. Time-dependent analyses revealed two-step, slow-binding inhibition. The behavior of 1was typical; initial formation of an enzyme–inhibitor complex (EI) obeyed an apparent KIof ∼30 μM with forward (k5) and reverse (k6) rate constants for isomerization to an EI* complex of 0.18 and 0.08 min–1, respectively. In contrast, 6showed a lower KIfor the initial encounter complex (∼1.5 μM), substantially faster isomerization to EI* (k5= 0.91 min–1), and slower back conversion of EI* to EI (k6= 0.04 min–1). Thus, the overall inhibition constants, KI*, for 1and 6were 10 and 0.06 μM, respectively. These findings were consistent with docking predictions of a favorable binding mode and a second, less tightly bound pose for 6at MtSK. Our results suggest that manzamines, in particular 6, constitute a new scaffold from which drug candidates with novel mechanisms of action could be designed for the treatment of tuberculosis by targeting MtSK.

The ecological responses of diatoms to pollution and nutrient enrichment, caused by domestic and municipal sewage, in the five fresh water ponds have been examined. It was observed that diatoms were completely absent in P3 and some species were also absent in P1 and P2. Similarly, diatom diversity was lower in P1 and P2 than in P4 and P5. However, diatom abundance was higher in P4. The Biological Index for Diatoms indicates a better water quality in P4 and P5 than in P1, P2 and P3. It was suggested that diatoms are useful for biological monitoring of water quality.

The growth pattern of two species of Scytonema, S. coactile and S. stuposum, isolated from the twilight zone of a cave and from a soil crust, respectively was studied under different light and dark regimes. The organism from the cave showed a better growth capability at the lower light intensity of 2.5 W .m-2, and utilized several exogenous sugars for its chemoheterotrophic as well as mixotrophic growth. To the contrary, S. stuposum from the soil crust grew well at a higher light intensity of 7.5 W .m-2 and did not grow in the dark utilizing exogenous sugars except fructose and mannose, showing that substrate specificity and efficiency of substrate utilization vary from species to species and also under light and dark regime. S. stuposum induced several proteins for mixotrophic and heterotrophic growth in the presence of fructose whereas S. coactile did not require induction of any protein for growth in darkness as it was adapted to grow in such a habitat in the cave.