Exploring the Effects of Selenium and Brassinosteroids on Photosynthesis and Protein Expression Patterns in Tomato Plants under Low Temperatures.

This study aimed to assess the effects of low-temperature stress on two tomato cultivars (S-22 and PKM-1) treated with 24-epibrassinolide (EBL) and selenium (Se) by determining the changes in the proteomics profiles, growth biomarkers, biochemical parameters, and physiological functions. The growth parameters, photosynthetic traits, and activity of nitrate reductase in the S-22 and PKM-1 plants were markedly reduced by exposure to low temperatures. However, the combined application of EBL and Se under different modes significantly enhanced the aforementioned parameters under stress and non-stress conditions. Exposure to low temperatures increased the activities of the antioxidant enzymes (catalase, peroxidase, and superoxide dismutase) and the proline content of leaves, which were further enhanced by treatment with Se and EBL in both varieties. This research sheds light on the potential for employing exogenous EBL and Se as crucial biochemical tactics to assist tomato plants in surviving low-temperature stress. Moreover, the differentially expressed proteins that were involved in plant metabolism following the combined application of EBL and Se under low-temperature stress were additionally identified. Functional analysis revealed that the Q54YH4 protein plays an active role against plant stressors. The conserved regions in the protein sequences were analyzed for assessing the reliability of plant responses against the external application of EBL and Se under low temperatures.

Metabolic and Proteomic Perspectives of Augmentation of Nutritional Contents and Plant Defense in Vigna unguiculata.

The current study enlists metabolites of Alstonia scholaris with bioactivities, and the most active compound, 3-(1-methylpyrrolidin-2-yl) pyridine, was selected against Macrophomina phaseolina. Appraisal of the Alstonia metabolites identified the 3-(1-methylpyrrolidin-2-yl) pyridine as a bioactive compound which elevated vitamins and nutritional contents of Vigna unguiculata up to ≥18%, and other physiological parameters up to 28.9%. The bioactive compound (0.1%) upregulated key defense genes, shifted defense metabolism from salicylic acid to jasmonic acid, and induced glucanase enzymes for improved defenses. The structural studies categorized four glucanase-isozymes under beta-glycanases falling in (Trans) glycosidases with TIM beta/alpha-barrel fold. The study determined key-protein factors (Q9SAJ4) for elevated nutritional contents, along with its structural and functional mechanisms, as well as interactions with other loci. The nicotine-docked Q9SAJ4 protein showed a 200% elevated activity and interacted with AT1G79550.2, AT1G12900.1, AT1G13440.1, AT3G04120.1, and AT3G26650.1 loci to ramp up the metabolic processes. Furthermore, the study emphasizes the physiological mechanism involved in the enrichment of the nutritional contents of V. unguiculata. Metabolic studies concluded that increased melibiose and glucose 6-phosphate contents, accompanied by reduced trehalose (-0.9-fold), with sugar drifts to downstream pyruvate biosynthesis and acetyl Co-A metabolism mainly triggered nutritional contents. Hydrogen bonding at residues G.357, G.380, and G.381 docked nicotine with Q9SAJ4 and transformed its bilobed structure for easy exposure toward substrate molecules. The current study augments the nutritional value of edible stuff and supports agriculture-based country economies.

Liquiritin elicitation can increase the content of medicinally important glucosinolates and phenolic compounds in Chinese kale plants.

BACKGROUND: Brassica oleracea var. alboglabra (Chinese kale) is an important vegetable grown in southern China. This study was aimed at searching for environmentally friendly and affordable approaches to increase the production of medicinally relevant glucosinolates and phenolic compounds in Chinese kale plants. For this purpose, the foliar application of liquiritin at 0 (control), 250, 500 and 750 ppm was tested starting from the four-leaf stage and repeated every two weeks until plants were two months old. RESULTS: Foliar application of liquiritin in Chinese kale plants significantly increased glucosinolates and total phenolic content, in a dose-dependent manner. Compared with control plants, 2.3- and 1.9-fold increases in yields of glucosinolates and total phenolic content, respectively, were corroborated in Chinese kale plants treated with 750 ppm of liquiritin. Along with rises in the content of eight different glucosinolates, liquiritin elicitation effectively increased the concentration of glycosilated and acylated flavonoids and hydroxycinnamic acids. The expression of genes involved in glucosinolate and phenolic biosynthesis was significantly higher in liquiritin-treated plants as compared to controls. CONCLUSIONS: Liquiritin elicitation is a feasible and environmentally friendly practice for increasing the production of medicinally important glucosinolates and phenolic compounds in Chinese kale, which may improve this plant's value as a nutraceutical food. This study also contributes to understanding the molecular mechanisms underlying liquiritin elicitation. This is the first report documenting the use of liquiritin for an elicitation purpose in plants. © 2019 Society of Chemical Industry.

Proteomic and physiological assessment of stress sensitive and tolerant variety of tomato treated with brassinosteroids and hydrogen peroxide under low-temperature stress.

The aim of current investigation was to perform proteomics and physio-chemical studies to dissect the changes in contrasting varieties (S-22 and PKM-1) of Lycopersicon esculentum under low-temperature stress. Plant grown under variable low-temperature stress were analysed for their growth biomarkers, antioxidant enzyme activities, and other physiological parameters, which headed toward the determination of protein species responding to low-temperature and 24-epibrassinolide (EBL) concentrations. The plants grown under temperatures, 20/14, 12/7, and 10/3 °C recorded significantly lower growth biomarkers, SPAD chlorophyll, net photosynthetic rate and carbonic anhydrase activity in S-22 and PKM-1. Moreover, the combined effect of EBL and hydrogen peroxide (H2O2) significantly improved the parameters mentioned above and consecutively upgraded the different antioxidant enzymes (CAT and SOD) with higher accumulation of proline under stress and stress-free environments. Furthermore, proteomics study revealed that the maximum number of differentially expressed proteins were detected in S-22 (EBL + H2O2); while treatment with EBL + H2O2 + low temperature lost expression of 20 proteins. Overall, three proteins (O80577, Q9FJQ8, and Q9SKL2) took a substantial part in the biosynthesis of citrate cycle pathway and enhanced the growth and photosynthetic efficiency of tomato plants under low-temperature stress.