Chemical characterization, nematicidal and antioxidant activities of Thymus linearis Benth.

Thymus linearis and its essential oil (EO) are used to cure a range of diseases in traditional medicine. GC-MS analysis of Thymus linearis EO revealed the presence of sixty-four components. Thymol (50.62%), carvacrol (13.23 %), carvacrol acetate (7.72%), -bisabolene (5.47%) and o-cymene (5.47%) are the only five basic constituents in the oil which accounts for 82.07% of oil. When compared to other compounds, the EO and its primary components thymol and carvacrol had the largest proportion of mortality in Meloidogyne javanica. Carvacrol has also been proven to be helpful in suppressing the hatching of M. javanica eggs. This is the first time T. linearis EO and its constituents, such as borneol and caryophyllene, have been studied for nematicidal action. The antioxidant activity of EO components and active compounds was assessed using the ABTS radical scavenging method. Thymol and carvacrol were found to exhibit high antioxidant activity. The IC50 of thymol and carvacrol are found to be 38.18 g/ml and 49.65 g/ml, respectively and are comparable to the positive control trolox (47.12 g/ml). Results clearly showed high potency for EO and its constituents, thymol and carvacrol as nematicidal and antioxidant agents.

Scrutinizing the Application of Saline Endophyte to Enhance Salt Tolerance in Rice and Maize Plants.

The present study aimed to witness the plant-microbe interaction associated with salt tolerance in crops. We isolated the endophytic microbe from the root zone of halophytic grass. Later, the salt tolerance of the endophyte was tested in the saline medium and was identified using nucleotide sequencing (GenBank under the accession numbers: SUB9030920 AH1_AHK_ITS1 MW570850: SUB9030920 AH1_AHK_ITS4 MW570851). Rice and maize seeds were coated with identified endophyte Aspergillus terreus and were sown in separate plastic pots. Later 21-day-old seedlings were subjected to three NaCl concentrations, including 50, 100, and 150 mM salt stress. Under saline conditions, A. terreus showed a substantial increase in growth, biomass, relative water content, oxidative balance, and photochemical efficiency of rice and maize plants. The data reflected that the stimulation of gibberellic acid (GA) in treated leaves may be the main reason for the upregulation of photosynthesis and the antioxidant defense cascade. The data also depict the downregulation of oxidative damage markers malondialdehyde, hydrogen peroxide in rice and maize plants. Conclusively, salt-tolerant endophytic fungus A. terreus explicitly displayed the positive plant-microbe interaction by developing salt tolerance in rice and maize plants. Salt tolerance by endophytic fungus coincides with the enhanced GA concentration, which illustrated the stimulated physiological mechanism and gene in response to the extreme environmental crisis, resulting in improved crop productivity.