Agricultural crops are facing major restraints with the rapid augmentation of global warming, salt being a major factor affecting productivity. Tomato (Solanum lycopersicum) plant has immense nutritional significance; however, it can be negatively influenced by salinity stress. Nanoparticles (NPs) have excellent properties, due to which these particles are used in agriculture to enhance various growth parameters even in the presence of abiotic stresses. The objective of this study was to investigate the effects of silicon NPs (Si-NPs) through root dipping and foliar spray on tomato in the presence/absence of salt stress. Plant root and leaf were used for the measurements of morphological, physiological, and biochemical parameters treated with Si-NPs under salt stress. At 45 days after sowing, the activity of antioxidant enzymes, photosynthesis, mineral concentration, chlorophyll index, and growth attributes of tomato plants were measured. The developmental processes of tomato plants were severely slowed down by salt stress upto 35.8% (shoot dry mass), 44.3% (root dry mass), 51% (shoot length), and 62% (root length), but this reduction was mitigated by the treatment of Si-NPs. Application of Si-NPs significantly increased the growth attributes (height and dry weight), mineral content [magnesium (Mg), potassium (K), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn)], photosynthesis [net photosynthetic rate (P N), stomatal conductance (gs), transpiration rate (E), internal CO2 concentration (Ci)], and activity of antioxidative enzymes including superoxide dismutase and catalase in salt stress. Foliar application of Si-NPs in tomato plants appears to be more effective over root dipping and alleviates the salt stress by increasing the plant's antioxidant enzyme activity.
Carrot is a vital supply of dietary fiber, vitamins, and carotenoids, and it is also rich in antioxidants and minerals. Soil salinity significantly reduces the yield and quality of carrots. Mycorrhiza inoculum (AMF) is known to improve morphological and biochemical traits of vegetables even under saline conditions. But the role of AMF in combating soil salinity effect in carrot is not studied in detail. Therefore here, in the first set, carrot seeds are inoculated with microbes in a pot experiment under polyhouse condition. In total, we applied 7 treatments with different combinations of Mycorrhiza inoculum (Glomus mosseae (Gm) and Gigaspora gigantea (Gg)) and phosphate solubilizing bacteria (Pseudomonas fluroscens (Pf)). In pot experiment study the best two treatments were the combination of Gm + Pf + GG and Pf + GG. Both of these treatments were selected for validation under the open field conditions. Primarily, there seems to be a promising opportunity for AMF application to carrots under pot culture as well as under field trials because of promising effect towards morphological parameters, especially root weight, and disparities in nutrients and metabolites. Overall, our study highlights mycorrhizal fungi and other microbes' efficacy in achieving a successful carrot production under salinity stress.
Cadmium (Cd) metal toxicity is a crucial ecological matter that requires immediate efforts to mitigate it. Brassica juncea plants were exposed to Cd (0 and 200 µM as CdSO4) and foliar application of 24-Epibrassinolide (EBR) (0, 10-7 and 10-5 M). The toxic effect of Cd was evident in terms of declined growth and biomass yield, lowered levels of pigment content and chlorophyll fluorescence, and reduction in gas exchange attributes. The levels of proline and glycinebetaine increased in response to Cd treatment. There was an imperative rise in the contents of H2O2 and malondialdehyde as well as electrolyte leakage in the Cd-stressed plants. With the application of EBR, there was a significant replenishment in growth attributes and photosynthetic efficacy. The contents of ROS (reactive oxygen species) and malondialdehyde as well as electrolyte leakage were reduced by the hormone supplementation. Enhancement in the contents of glutathione and ascorbic acid, and the activities of enzymes of the antioxidative defense system and glyoxalase system was recorded in response to Cd as well as hormone treatment. The in situ levels of Cd in roots and shoot were augmented in response to Cd treatment, but were found to be lowered by the EBR application.
