Indiscriminate and irrational use of antibiotics has created an unprecedented challenge for human civilization due to microbe’s development of antimicrobial resistance. It is difficult to treat bacterial infection due to bacteria’s ability to develop resistance against antimicrobial agents. Antimicrobial agents are categorized according to their mechanism of action, i.e., interference with cell wall synthesis, DNA and RNA synthesis, lysis of the bacterial membrane, inhibition of protein synthesis, inhibition of metabolic pathways, etc. Bacteria may become resistant by antibiotic inactivation, target modification, efflux pump and plasmidic efflux. Currently, the clinically available treatment is not effective against the antibiotic resistance developed by some bacterial species. However, plant-based antimicrobials have immense potential to combat bacterial, fungal, protozoal and viral diseases without any known side effects. Such plant metabolites include quinines, alkaloids, lectins, polypeptides, flavones, flavonoids, flavonols, coumarin, terpenoids, essential oils and tannins. The present review focuses on antibiotic resistance, the resistance mechanism in bacteria against antibiotics and the role of plant-active secondary metabolites against microorganisms, which might be useful as an alternative and effective strategy to break the resistance among microbes.

The agricultural crops are often affected by the scarcity of fresh water. Seasonal drought is a major constraint on Northeast Indian agriculture. Almost 80% of the agricultural land in this region is acidic and facing severe drought during the winter period. Apart from classical breeding and transgenic approaches, the application of plant-growth-promoting bacteria (PGPB) is an alternative strategy for improving plant fitness under stressful conditions. The 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing PGPB offer drought stress tolerance by regulating plant ethylene levels. The aim of the present study was to evaluate the consortium effect of three ACC-deaminase producing rhizobacteria – Ochrobactrum pseudogrignonenseRJ12, Pseudomonas sp.RJ15 and Bacillus subtilisRJ46 on drought stress alleviation in Vigna mungo L. and Pisum sativum L. Consortium treatment significantly increase seed germination percentage, root length, shoot length, and dry weight of treated plants. An elevated production of reactive oxygen species scavenging enzymes and cellular osmolytes; higher leaf chlorophyll content; increase in relative water content and root recovery intension were observed after consortium treatment in comparison with the uninoculated plants under drought conditions. The consortium treatment decreased the ACC accumulation and down-regulated ACC-oxidase gene expression. This consortium could be an effective bio-formulator for crop health improvement in drought-affected acidic agricultural fields.

The kinase-inducible domain interacting (KIX) domain is a highly conserved independently folding three-helix bundle that serves as a docking site for transcription factors, whereupon promoter activation and target specificity are achieved during gene regulation. This docking event is a harbinger of an intricate multi-protein assembly at the transcriptional apparatus and is regulated in a highly precise manner in view of the critical role it plays in multiple cellular processes. KIX domains have been characterized in transcriptional coactivators such as p300/CREB-binding protein and mediator of RNA polymerase II transcription subunit 15, and even recQ protein-like 5 helicases in various organisms. Their targets are often intrinsically disordered regions within the transactivation domains of transcription factors that attain stable secondary structure only upon complexation with KIX. In this article, we review the KIX domain in terms of its sequence and structure and present the various implications of its ability to act as a transcriptional switch, the mechanistic basis of molecular recognition by KIX, its binding specificity, target promiscuity, combinatorial potential and unique mode of regulation via allostery. We also discuss the possible roles of KIX domains in plants and hope that this review will accelerate scientific interest in KIX and pave the way for novel avenues of research on this critical domain.

This is a very first attempt to compile a checklist of spiders from Gujarat.  It is a result of primary data as well as based on published literature.  The spider diversity of Gujarat consists of 415 species under 169 genera and 40 families.  Out of these, 29 genera and 17 families are endemic to Gujarat.  Overall, high spider diversity was recorded from zone III with 33 families, 132 genera and 278 species.  Whereas, the zone with the least spider records was zone VI with only 16 families, 39 genera and 70 species.  This is an under estimated number and many new records as well as new species are expected as a result of more systematic studies on spiders in this region.

No abstract

Pseudomonas is an efficient plant growth-promoting rhizobacteria; however, among the limiting factors for its commercialization, tolerance for high temperature is the most critical one. After screening 2,500 Pseudomnas sp. strains, a high temperature tolerant-strain Pseudomonas putida NBRI0987 was isolated from the drought-exposed rhizosphere of chickpea (Cicer arietinum L. cv. Radhey), which was grown under rain-fed conditions. P. putida NBRI0987 tolerated a temperature of 40 degrees C for < or = 5 days. To the best of our knowledge, this is the first report of a Pseudomnas sp. demonstrating survival estimated by counting viable cells under such a high temperature. P. putida NBRI0987 colony-forming unit (CFU)/ml on day 10 in both the absence and presence of MgSO4 x 7H2O (MgSO4) in combination with glycerol at 40 degrees C were 0.0 and 1.7 x 10(11), respectively. MgSO4 plus glycerol also enhanced the ability of P. putida NBRI0987 to tolerate high temperatures by inducing its ability to form biofilm. However, production of alginate was not critical for biofilm formation. The present study demonstrates overexpression of stress sigma factor sigma(S) (RpoS) when P. putida NBRI0987 is grown under high-temperature stress at 40 degrees C compared with 30 degrees C. We present evidence, albeit indirect, that the adaptation of P. putida NBRI0987 to high temperatures is a complex multilevel regulatory process in which many different genes can be involved.

No abstract

Plant growth promotion is a multigenic process under the influence of many factors; therefore an understanding of these processes and the functions regulated may have profound implications. Present study reports microarray analysis of Arabidopsis thaliana plants inoculated with Pseudomonas putida MTCC5279 (MTCC5279) which resulted in significant increase in growth traits as compared with non-inoculated control. The gene expression changes, represented by oligonucleotide array (24652 genes) have been studied to gain insight into MTCC5279 assisted plant growth promotion in Arabidopsis thaliana. MTCC5279 induced upregulated Arabidopsis thaliana genes were found to be involved in maintenance of genome integrity (At5g20850), growth hormone (At3g23890 and At4g36110), amino acid synthesis (At5g63890), abcissic acid (ABA) signaling and ethylene suppression (At2g29090, At5g17850), Ca +2 dependent signaling (At3g57530) and induction of induced systemic resistance (At2g46370, At2g44840). The genes At3g32920 and At2g15890 which are suggested to act early in petal, stamen and embryonic development are among the downregulated genes. We report for the first time MTCC5279 assisted repression of At3g32920, a putative DNA repair protein involved in recombination and DNA strand transfer in a process of rapid meiotic and mitotic division.