Nanopriming Action of Microwave-Assisted Biofunctionalized ZnO Nanoparticles to Enhance the Growth under Moisture Stress in Vigna radiata.

Bare and stabilized zinc oxide nanoparticles (ZnO NPs) were prepared by a microwave-assisted method and used as a priming agent to improve the morphological, physiological, and biochemical quality of Vigna radiata. The priming action was made under normal and moisture stress conditions. A microwave reactor of 850 watts power was used to heat 30 mL of a nanocolloidal solution at 140 °C for 20 min. The stable spherical ZnO NPs at 50.4 mV with 28.2 nm particle size were generated and capped with different biomolecules, cysteine and PVA, to get biostabilized ZnO NPs at 48.8 and 108.5 nm with ζ potentials of -56.2 and -52.0 mV, respectively, holding distinct morphology. The nanopriming effect was studied in V. radiata seeds for bare ZnO and capped ZnO NPs under normal and moisture stress environments. Cysteine-capped ZnO NPs at 250 ppm showed improved germination (90 and 76%), radicle growth (7.6 and 3.6 cm), seedling Vigor (3064 and 1816), dry matter production (145.06 and 96.92 mg/25 seedlings), and hydrolytic (α-amylase and protease) and antioxidant (peroxidase and superoxide dismutase) enzyme activity under normal and moisture stress conditions. The improved priming action of cysteine-capped ZnO NPs is due to increased cell elongation and cell division in the radicle. The uptake and translocation of ZnO NPs in the V. radiata root are evidenced by the presence of an 11.4 ppm zinc level, which was also supported by EDAX and FITC labeling results.

Comparative Metabolomic Profiling of Horse Gram (Macrotyloma uniflorum (Lam.) Verdc.) Genotypes for Horse Gram Yellow Mosaic Virus Resistance.

Horse gram (Macrotyloma uniflorum (Lam.) Verdc.) is an under-utilized legume grown in India. It is a good source of protein, carbohydrates, dietary fiber, minerals, and vitamins. We screened 252 horse gram germplasm accessions for horse gram yellow mosaic virus resistance using the percent disease index and scaling techniques. The percentage values of highly resistant, moderately resistant, moderately susceptible, susceptible, and highly susceptible were 0.34, 13.89, 38.89, 46.43, and 0.34, respectively. Repetitive trials confirmed the host-plant resistance levels, and yield loss was assessed. The present disease index ranged from 1.2 to 72.0 and 1.2 to 73.0 during the kharif and rabi seasons of 2018, respectively. The maximum percent yield loss was noticed in the HS (75.0 -89.4), while HR possessed the minimum (1.2-2.0). The methanolic leaf extracts of highly resistant and highly susceptible genotypes with essential controls were subjected to gas chromatography-mass spectrometry analysis. Differential accumulation of metabolites was noticed, and a total of 81 metabolites representing 26 functional groups were identified. Both highly resistant and susceptible genotypes harbored eight unique classes, while ten biomolecules were common. The hierarchical cluster analysis indicated a distinct metabolite profile. Fold change in the common metabolites revealed an enhanced accumulation of sugars, alkanes, and carboxylic acids in the highly resistant genotype. The principal component analysis plots explained 93.7% of the variation. The metabolite profile showed a significant accumulation of three anti-viral (octadecanoic acid, diphenyl sulfone, and 2-Aminooxazole), one insecticidal (9,10-Secocholesta-5,7,10(19)-triene-3,24,25-triol), one antifeedant (cucurbitacin B), and six metabolites with unknown biological function in the highly resistant genotype.

Comparative transcriptome and metabolome profiling in the maturing seeds of contrasting cluster bean (Cyamopsis tetragonoloba L. Taub) cultivars identified key molecular variations leading to increased gum accumulation.

Cluster bean (Guar) is the major source of industrial gum. Knowledge on the molecular events regulating galactomannan gum accumulation in guar will pave way for accelerated development of gummy guar genotypes. RNA Seq analysis in the immature seeds of contrasting cluster bean genotypes HGS 563 (gum type) and Pusa Navbahar (vegetable type) resulted in the generation of 19,855,490 and 21,488,472 quality reads. Data analysis identified 4938 differentially expressed genes between the gummy vs vegetable genotypes. A set of 2241 genes were up-regulated and 2587 genes were down-regulated in gummy guar. Significant up-regulation of genes involved in the biosynthesis of galactomannan and cell wall storage polysaccharides was observed in the gummy HGS 563. Genes involved in carotenoids, flavonoids, non mevalonic acid, terpenoids, and wax metabolism were also up-regulated in HGS 563. Mannose and galactose were the major nucleotide sugars in Pusa Navbahar and HGS 563 immature seeds. Immature seeds of HGS 563 showed high concentration of mannose and galactose accumulation compared to Pusa Navbahar. qRT-PCR analysis of selected genes confirmed the findings of transcriptome data.