24 research outputs found
Research and Reviews: Journal of Microbiology and Biotechnology Essential Amendments to Control Resistance to Antibiotics among Bacteria
Antiviral Silencing and Suppression of Gene Silencing in Plants
RNA silencing is an evolutionary conserved sequence-specific gene inactivation mechanism that contributes to the control of development, maintains heterochromatin, acts in stress responses, DNA repair and defends against invading nucleic acids like transposons and viruses. In plants RNA silencing functions as one of the main immune systems. RNA silencing process involves the small RNAs and trans factor components like Dicers, Argonautes and RNA-dependent RNA poly- merases. To deal with host antiviral silencing responses viruses evolved mecha- nisms to avoid or counteract this, most notably through expression of viral suppressors of RNA silencing. Due to the overlap between endogenous and antiviral silencing pathways while blocking antiviral pathways viruses also impact endogenous silencing processes. Here we provide an overview of antiviral silencing pathway, host factors implicated in it and the crosstalk between antiviral and endogenous branches of silencing. We summarize the current status of knowledge about the viral counter-defense strategies acting at various steps during virus infection in plants with the focus on representative, well studied silencing suppres- sor proteins. Finally we discuss future challenges of the antiviral silencing and counter-defense research field
First report of âCandidatus Liberibacter asiaticusâ associated with Citrus decumana (Beejapuraka) in South India
PGP potential, abiotic stress tolerance and antifungal activity of <i>Azotobacter</i> strains isolated from paddy soils
322-331Azotobacter
strains were isolated by serial dilution method and colonies were viscous,
smooth, glistening, and brown to black colour on Jensonâs N-free agar.
Morphological and biochemical tests showed characteristic features of Azotobacter. Further, molecular analyses
revealed the presence of different Azotobacter
species viz., <i style="mso-bidi-font-style:
normal">A. armeniacus, A. chroococcum,
A. salinestris, A. tropicalis and A. vinelandii. The isolates were tested
for their ability of nitrogen fixation, indole acetic acid (IAA), gibberllic
acid production and phosphate solubilization. Four isolates (GVT-1, GVT-2
KOP-11 and SND-4)
were efficient in fixation of highest amount of N2 (29.21 ÎŒg NmL-1day-1),
produced IAA (25.50 ”g mL-1),
gibberllic acid (17.25 ÎŒg 25 mL-1) and formed larger P solubilizing
zone (13.4 mm). Some of the Azotobacter
strains were produced siderophores, hydrogen cyanide and were positive for
ammonia production with respect to antifungal activity of <i style="mso-bidi-font-style:
normal">Azotobacter was tested with dual culture method and A. tropicalis inhibited the growth of Fusarium, Aspergillus and Alternaria species. <i style="mso-bidi-font-style:
normal">Azotobacter isolates were tested against salt (0-10%), temperature
(4-55ÂșC), pH (5.0-10) and insecticide chloropyrifos
(0-3%) tolerance study. Among them, A.
chroococcum was found tolerant to a maximum of 6% NaCl with a temperature
of 35-45ÂșC and to a pH up to 8. All the 4 strains showed effective growth
against 3% chloropyrifos concentration. The studies revealed that the Azotobacter strains not only produced
plant growth promoting substances but are also tolerant to abiotic stresses
such as temperature, pH and insecticides.</span