Publications by authors named "Savitha De Britto"

7 Publications

  • Page 1 of 1

Genome-Wide Identification, Diversification, and Expression Analysis of Lectin Receptor-Like Kinase (LecRLK) Gene Family in Cucumber under Biotic Stress.

Int J Mol Sci 2021 Jun 19;22(12). Epub 2021 Jun 19.

Laboratory of Plant Healthcare and Diagnostics, P.G. Department of Biotechnology and Microbiology, Karnatak University, Dharwad 580003, India.

Members of the lectin receptor-like kinase (LecRLKs) family play a vital role in innate plant immunity. Few members of the LecRLKs family have been characterized in rice and , respectively. However, little literature is available about LecRLKs and their role against fungal infection in cucumber. In this study, 60 putative cucumber LecRLK (CsLecRLK) proteins were identified using genome-wide analysis and further characterized into L-type LecRLKs (24) and G-type LecRLKs (36) based on domain composition and phylogenetic analysis. These proteins were allocated to seven cucumber chromosomes and found to be involved in the expansion of the gene family. Subcellular localization of CsaLecRLK9 and CsaLecRLK12 showed green fluorescence signals in the plasma membrane of leaves. The transcriptional profiling of genes showed that L-type LecRLKs exhibited functional redundancy as compared to G-type LecRLKs. The qRT-PCR results indicated that both L- and G-type LecRLKs showed significant response against plant growth-promoting fungi (PGPF- Rifai), powdery mildew pathogen (PPM- (Castagne) V.P. Heluta), and combined (PGPF+PPM) treatments. The findings of this study contribute to a better understanding of the role of cucumber genes in response to PGPF, PPM, and PGPF+PPM treatments and lay the basis for the characterization of this important functional gene family.
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http://dx.doi.org/10.3390/ijms22126585DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8234520PMC
June 2021

Ameliorated Antibacterial and Antioxidant Properties by Mediated Green Synthesis of Silver Nanoparticles.

Biomolecules 2021 04 4;11(4). Epub 2021 Apr 4.

Laboratory of Plant Healthcare and Diagnostics, PG Department of Biotechnology and Microbiology, Karnatak University, Dharwad 580 003, Karnataka, India.

Biosynthesis of silver nanoparticles using beneficial is a simple, eco-friendly and cost-effective route. Secondary metabolites secreted by act as capping and reducing agents that can offer constancy and can contribute to biological activity. The present study aimed to synthesize silver nanoparticles using cell filtrate and investigate different bioactive metabolites based on LC-MS/MS analysis. The synthesized silver nanoparticles (AgNPs) from were characterized by ultraviolet-visible spectrophotometry, Fourier transform infrared spectrometry (FT-IR), energy-dispersive spectroscopy (EDS), dynamic light scattering (DLS), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The surface plasmon resonance of synthesized particles formed a peak centered near 438 nm. The DLS study determined the average size of AgNPs to be 21.49 nm. The average size of AgNPs was measured to be 72 nm by SEM. The cubic crystal structure from XRD analysis confirmed the synthesized particles as silver nanoparticles. The AgNPs exhibited remarkable antioxidant properties, as determined by DPPH and ferric reducing antioxidant power (FRAP) assay. The AgNPs also exhibited broad-spectrum antibacterial activity against two Gram-positive bacteria ( and ) and two Gram-negative bacteria ( and ). The minimum inhibitory concentration (MIC) of AgNPs towards bacterial growth was evaluated. The antibacterial activity of AgNPs was further confirmed by fluorescence microscopy and SEM analysis.
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http://dx.doi.org/10.3390/biom11040535DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8066458PMC
April 2021

Myco-engineered selenium nanoparticles elicit resistance against tomato late blight disease by regulating differential expression of cellular, biochemical and defense responsive genes.

J Biotechnol 2021 Jan 23;325:196-206. Epub 2020 Oct 23.

Laboratory of Plant Healthcare and Diagnostics, PG Department of Studies in Biotechnology and Microbiology, Karnatak University, Pavate Nagar, Dharwad, 580 003, Karnataka, India. Electronic address:

With the advent of rapid evolution of oomycete pathogen lineages, the need for sustainable agriculture practices has become the need of the hour. The late blight of tomato caused by Phytopthora infestans, has recently emerged as one such devastating disease in India that led to huge crop losses. Hence, in the present work seed priming with mycogenic selenium nanoparticles (SeNPs) for elicitation of resistance against tomato late blight disease is investigated. It also aims to understand the defense responses triggered by SeNPs at cellular, biochemical and transcriptomic levels. Enhanced plant growth parameters were observed in bioactive SeNPs-primed tomato plants as compared to control plants. SeNPs-primed and pathogen inoculated plants exhibited a significant protection of 72.9 % against late blight disease. The primed plants also recorded a remarkable accumulation of lignin, callose and hydrogen peroxide that serve as the cellular defense over the control plants. Further, an elevated level of lipoxygenase (LOX), phenylalanine lyase (PAL), β-1,3-glucanase (GLU), superoxide dismutase (SOD) corroborated the biochemical defense in primed plants, which was also reflected in the corresponding transcriptome profiling of the genes encoding the enzymes. Thus, the present study represents an orchestrated correlation between resistance and defense responses incited by SeNPs against tomato late blight disease, which can be used as nano-biostimulant fungicide in protecting tomato plants.
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http://dx.doi.org/10.1016/j.jbiotec.2020.10.023DOI Listing
January 2021

Exogenous priming of chitosan induces upregulation of phytohormones and resistance against cucumber powdery mildew disease is correlated with localized biosynthesis of defense enzymes.

Int J Biol Macromol 2020 Nov 16;162:1825-1838. Epub 2020 Aug 16.

Department of Studies in Biotechnology, University of Mysore, Manasagangotri, Mysuru 570 006, Karnataka, India.

In recent years, exploration of biopolymer-based materials to avoid hazardous chemicals in agriculture has gained enormous importance for sustainable crop improvement. In the present study, chitosan a biopolymer derived from crab-shell was used in different concentrations as priming agent to cucumber seeds and were evaluated for its effect to enhance plant growth parameters as well as its ability to induce resistance against powdery mildew disease. Among the treatments, seeds-primed with 2.5 mg/mL exhibited early seedling germination of 90% and vigour of 2665 and also remarkably enhanced the cucumber growth parameters which might be fairly attributed to the stimulation of phytohormones content in primed plants over the controls. More importantly, under greenhouse conditions a significant induced disease protection of 66.6% against powdery mildew disease was noticed in chitosan-pretreated plants at 2.5 mg/mL. The induced resistant plants also showed a significant deposition of lignin, callose and HO. Notably, polyphenol oxidase, phenylalanine ammonia-lyase, peroxidase and glucanase defense-responsive enzymes were upregulated in chitosan-primed plants. Considered together, these results determine that the susceptible cucumber cultivar elicits immunity after perception of priming with chitosan to upregulate phytohormones and synthesize defense-responsive enzymes, thereby induce resistance against powdery mildew disease and strengthen the growth-promotion of cucumber plants.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.08.124DOI Listing
November 2020

Synchronised regulation of disease resistance in primed finger millet plants against the blast disease.

Biotechnol Rep (Amst) 2020 Sep 2;27:e00484. Epub 2020 Jun 2.

Laboratory of Plant Healthcare and Diagnostics, P.G. Department of Biotechnology and Microbiology, Karnatak University, Dharwad - 580003, Karnataka, India.

Plants, being sessile, are exposed to an array of abiotic and biotic stresses. To adapt towards the changing environments, plants have evolved mechanisms that help in perceiving stress signals wherein phytohormones play a critical role. They have the ability to network enabling them to mediate defense responses. These endogenous signals, functioning at low doses are a part of all the developmental stages of the plant. Phytohormones possess specific functions as they interact with each other positively or negatively through cross-talks. In the present study, variations in the amount of phytohormones produced during biotic stress caused due to infection was studied through targeted metabolomics in both primed and control finger millet plants. Histochemical studies revealed callose deposition at the site of pathogen entry in the primed plants indicating its role during plant defense. The knowledge on the genetic makeup during infection was obtained by quantification of MAP kinase kinases 1 and 2 () and lipoxygenase () genes, wherein the expression levels were high in the primed plants at 6 hours post-inoculation (hpi) compared to mock-control. Studies indicate the pivotal role of mitogen-activated protein kinase (MAPK or MAP kinases) during defense signalling. It is the first report to be studied on MAPK role in finger millet-blast disease response. Temporal accumulation of LOX enzyme along with its activity was also investigated due to its significant role during jasmonate synthesis in the plant cells. Results indicated its highest activity at 12 hpi. This is the first report on the variation in phytohormone levels in fingermillet - pathosystem upon priming which were substantiated through salicylic acid (SA) pathway.
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http://dx.doi.org/10.1016/j.btre.2020.e00484DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7327827PMC
September 2020

Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using and Their Fungicidal Ability Against Pathogenic Fungi of Apple Orchards.

Biomolecules 2020 03 9;10(3). Epub 2020 Mar 9.

Laboratory of Plant Healthcare and Diagnostics, PG Department of Biotechnology and Microbiology, Karnataka University, Dharwad 580003, Karnataka, India.

belonging to the Myrtaceae family was explored for the synthesis of zinc oxide nanoparticles and for biological applications. The aqueous extract of the synthesized zinc nanoparticles (ZnNPs) was characterized using UV-visible spectrophotometer, FTIR, SEM and TEM. The aqueous broth was observed to be an efficient reducing agent, leading to the rapid formation of ZnNPs of varied shapes with sizes ranging between 52-70 nm. In addition, antifungal activity of the biosynthesized ZnNPs was evaluated against major phytopathogens of apple orchards. At 100 ppm of ZnNPs, the fungal growth inhibition rate was found to be 76.7% for followed by 65.4 and 55.2% inhibition rate for and , respectively. The microscopic observations of the treated fungal plates revealed that ZnNPs damages the topography of the fungal hyphal layers leading to a reduced contraction of hyphae. This considerable fungicidal property of ZnNPs against phytopathogenic fungi can have a tremendous impact on exploitation of ZnNPs for fungal pest management and ensure protection in fruit crops.
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http://dx.doi.org/10.3390/biom10030425DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175351PMC
March 2020

Mycogenic Selenium Nanoparticles as Potential New Generation Broad Spectrum Antifungal Molecules.

Biomolecules 2019 08 28;9(9). Epub 2019 Aug 28.

Laboratory of Molecular Plant Pathology, Department of Biological and Environmental Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan.

The current challenges of sustainable agricultural development augmented by global climate change have led to the exploration of new technologies like nanotechnology, which has potential in providing novel and improved solutions. Nanotools in the form of nanofertilizers and nanopesticides possess smart delivery mechanisms and controlled release capacity for active ingredients, thus minimizing excess run-off to water bodies. This study aimed to establish the broad spectrum antifungal activity of mycogenic selenium nanoparticles (SeNPs) synthesized from and characterize the bioactive nanoparticles using UV-Vis spectroscopy, dynamic light scattering (DLS), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and high-resolution transmission electron microscopy (HR-TEM). The synthesized nanoparticles displayed excellent in vitro antifungal activity against and inhibited the infection of and on chili and tomato leaves at concentrations of 50 and 100 ppm, respectively. The SEM-EDS analysis of the bioactive SeNPs revealed a spherical shape with sizes ranging from 60.48 nm to 123.16 nm. The nanoparticles also possessed the unique property of aggregating and binding to the zoospores of at a concentration of 100 ppm, which was visualized using light microscope, atomic force microscopy, and electron microscopy. Thus, the present study highlights the practical application of SeNPs to manage plant diseases in an ecofriendly manner, due to their mycogenic synthesis and broad spectrum antifungal activity against different phytopathogens.
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http://dx.doi.org/10.3390/biom9090419DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6769984PMC
August 2019
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