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Efficacy of clinical antibiotics has decreased with increase in drug resistance against fungal pathogens. This work proposes a novel approach to combat fungal infections by combining antibiotics with essential oil from the leaves of Aegle marmelos (L.) Correa. GC-MS evaluation detected nine compounds with α-Phellandrene and d -Limonene as the major phytocompounds. The major phytocompounds were quantified by using standard calibration curve of α-Phellandrene and d -Limonene and the amount obtained was 385 ± 0.096 and 330 ± 0.100 ppm respectively. Additionally, the anti-candida activity of A. marmelos essential oil (AMEO) was evaluated using the agar well diffusion assay and showed zone of inhibition of 24 ± 0.5 and 22 ± 0.30 mm against both the C. albicans strains (ATCC 90028 and MTCC277), respectively. Further, the minimum inhibitory concentration (MIC) showed a fungicidal effect against both ATCC90028 and MTCC277 strains of C. albicans and ranged from 0.312 to 0.156% (v/v). The antifungal activity against C. albicans was found to be potent and effective. Synergistic potential was determined using time kill assay and checkerboard method showing increased antifungal efficacy of clinical drugs by 16 and 32 folds, with complete death of cells after 16 h. The assessment of the mode of action of essential oil and antibiotics alone and in combination was done through sorbitol test and Field Emission Scanning Electron Microscopy (FESEM) observations. The sorbitol test demonstrated that the antifungal activities of AMEO, both on their own and in combination with antibiotics, are not associated with the biosynthesis pathways of the cell wall. According to the results of the ergosterol test, AMEO combined with antibiotics appear to bind to the ergosterol in the membrane. This results in an increase in ion permeability, which ultimately leads to cell death. FESEM analysis also confirmed this by showing complete rupture and disruption of the fungal membrane of C. albicans cells treated with essential oil combined with antibiotics. At separate capacity in broth which means when they were used individually, they induced shrinkage and distortion. Thus represents an effective treatment for candidiasis by acting as a refinement in drug design. • Extraction of essential oil from the leaves of A. marmelos. • Ten phytocompounds were identified and major compounds were quantified using GC-MS. • Antifungal and synergistic potential of A. marmelos essential oil against C. albicans was evaluated. • A. marmelos essential oil exhibited antifungal activity against C. albicans (ATCC90028 and MTCC277).. • Synergism improved the antifungal activity of clinical drugs by 16 and 32 folds. [ABSTRACT FROM AUTHOR]

Abstract: Yellow mosaic disease caused by whitefly-transmitted bipartite Geminiviruses is one of the major constraints on productivity of a number of pulse crops. We have cloned the bipartite genome of Mungbean Yellow Mosaic India Virus isolated from infected Soybean. We report here that agroinfection of Soybean seedlings with a single uncut recombinant binary plasmid containing tandem dimers of both DNA A and DNA B resulted in 100% infectivity in susceptible varieties. To understand the mechanism of natural resistance in a Soybean variety, we compared the abundance of the viral RNAs in a resistant and a susceptible variety at the early time points after agroinfection. Whilst the resistant variety displayed synthesis but rapid degradation of the early viral RNAs; the degradation in the susceptible variety was delayed resulting in accumulation of those transcripts later in infection. Accumulation of the late viral transcripts and DNA replication were detectable only in the susceptible variety. This indicates that rapid degradation of the early viral transcripts, possibly through siRNA mechanism, is one of the probable mechanisms of natural resistance against geminivirus. [Copyright &y& Elsevier]

• Squalene epoxidase gene ArSQE from Asparagus racemosus was found to complement yeast erg1 mutant. • Over-expression of ArSQE provides terbinafine resistance in yeast and transgenic tobacco. • ArSQE imparts early germination and abiotic stress tolerance in transgenic tobacco. • Two bZIP TFs ArTGA1 and ArTGA2 were identified which regulate ArSQE by interacting with methyl jasmonate-responsive TGACG element. A. racemosus is a rich source of pharmacologically active steroidal saponins. Most of the studies are related to its chemistry and pharmacology, but the pathway involved in the biosynthesis of steroidal saponin is not much emphasized. Squalene epoxidase acts as a rate-limiting enzyme in this biosynthesis. In this study, we have selected root specific squalene epoxidase ArSQE from A. racemosus for its characterization. ArSQE was able to complement ergosterol auxotrophy in erg1 yeast mutants. Mutants were sensitive to the antifungal drug terbinafine, whereas ArSQE complementation made them tolerant to the same drug. ArSQE plays a significant role in early germination in transgenic tobacco. The transgenic tobacco seedlings overexpressing ArSQE were tolerant to terbinafine and abiotic stress. Expression analysis of transcripts in ArSQE transgenic lines suggests that it mostly affects ABA, GA, stress, and sterol related functions in transgenic tobacco. Further, root specific MeJA responsive A. racemosus bZIP transcription factors (TFs), ArTGA1 and ArTGA2, were identified that bind to MeJA responsive cis -element present in the promoter region of ArSQE. Characterization of ArSQE of A. racemosus provides new information about its regulation through MeJA responsive bZIP TF along with its role in the development and abiotic stress response in transgenic tobacco. [ABSTRACT FROM AUTHOR]