Trehalase Inhibitor Validamycin May Have Additional Mechanisms of Toxicology against Rhizoctonia cerealis

Membrane-bound trehalase enhances cadmium tolerance by regulating cell apoptosis in Neocaridina denticulata sinensis

Trehalase gene is mainly expressed in the digestive circulatory system for regulating energy metabolism and chitin synthesis in insects, but it is significantly expressed in gill for immunomodulation in shrimp. However, its function in regulating immunity, particularly metal resistance in crustaceans has yet to be elucidated. In this study, one Tre2 gene (NdTre2) was isolated from Neocaridina denticulata sinensis. It could bind to Cd2+ and inhibit its toxicity. Spatiotemporal expression analysis showed that the expression of NdTre2 was highest in the gill and significantly reduced at 12 h after Cd2+ stimulation. The transcriptomic analysis of the gill after NdTre2 knockdown showed that the expression of genes synthetizing 20E was up-regulated and the increased 20E could further induce apoptosis by activating the intrinsic mitochondrial pathway, exogenous death receptor-ligand pathway, and MAPK pathway. In vitro, overexpressing NdTre2 enhanced the tolerance of E. coli in Cd2+ environment. In summary, these results indicate that NdTre2 plays an essential role in regulating immunity and chitin metabolism in N. denticulata sinensis.

Old and new strategies in therapy and diagnosis against fungal infections

Fungal infections represent a serious global health threat. The new emerging pathogens and the spread of different forms of resistance are now hardly challenging the tools available in therapy and diagnostics. With the commonly used diagnoses, fungal identification is often slow and inaccurate, and, on the other hand, some drugs currently used as treatments are significantly affected by the decrease in susceptibility. Herein, the antifungal arsenal is critically summarized. Besides describing the old approaches and their mechanisms, advantages, and limitations, the focus is dedicated to innovative strategies which are designed, identified, and developed to take advantage of the discrepancies between fungal and host cells. Relevant pathways and their role in survival and virulence are discussed as their suitability as sources of antifungal targets. In a similar way, molecules with antifungal activity are reported as potential agents/precursors of the next generation of antimycotics. Particular attention was devoted to biotechnological entities, to their novelty and reliability, to drug repurposing and restoration, and to combinatorial applications yielding significant improvements in efficacy. KEY POINTS: • New antifungal agents and targets are needed to limit fungal morbidity and mortality. • Therapeutics and diagnostics suffer of delays in innovation and lack of targets. • Biologics, drug repurposing and combinations are the future of antifungal treatments.

Trehalose accumulation enhances drought tolerance by modulating photosynthesis and ROS-antioxidant balance in drought sensitive and tolerant rice cultivars

Trehalose being an integral part for plant growth, development and abiotic stress tolerance is accumulated in minute amounts in angiosperms with few exceptions from resurrection plants. In the current study, two rice cultivars differing in drought tolerance were used to analyse the role of trehalose in modulating photosynthesis and ROS-antioxidant balance leading to improvement in drought tolerance. Accumulation of trehalose in leaves of Vaisakh (drought-tolerant) and Aiswarya (drought-sensitive) rice cultivars was observed by spraying 50 mM trehalose and 100 µM validamycin A (trehalase inhibitor) followed by vacuum infiltration. Compared to stress sensitive Aiswarya cultivar, higher trehalose levels were observed in leaves of Vaisakh not only under control conditions but also under drought conditions corresponding with increased root length. The increase in leaf trehalose by treatment with trehalose or validamycin A corresponded well with a decrease in electrolyte leakage in sensitive and tolerant plants. Decreased ROS levels were reflected as increase in antioxidant enzyme activity and their gene expression in leaves of both the cultivars treated with trehalose or Validamycin A under control and drought conditions signifying the importance of trehalose in modulating the ROS-antioxidant balance for cellular protection. Further, higher chlorophyll, higher photosynthetic activity and modulation in other gas exchange parameters upon treatment with trehalose or validamycin A strongly suggested the beneficial role of trehalose for stress tolerance. Trehalose accumulation helped the tolerant cultivar adjust towards drought by maintaining higher water status and alleviating the ROS toxicity by effective activation and increment in antioxidant enzyme activity along with enhanced photosynthesis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01404-7.