Project description:Soil humic substances are known to positively influence plant growth and nutrition. In particular, low-molecular fractions have been shown to increase NO3- uptake and PM H+-ATPase activity and alter expression of related genes. Changes in maize root transcriptome due to treatment with nitrate (NO3-), Water-Extractable Humic Substances (WEHS) and NO3-+WEHS were analyzed.
Project description:Humic substances are principal components of soil organic matter. They have ecological importance as they intervene in regulating a large number of chemical and biological processes that occur in natural ecosystems. Their ability to improve plant growth has been well established in diverse plant species and growth conditions, although the mechanism responsible for this biological action is poorly understood. Microarray analysis might give us more information about up or down regulation of different biological processes. Wheat plants have been grown hydroponically and treated with Humic acid. Seeds were germinated in obscurity during 10 days, and grown in nutrient solution during 10 days. Harvests were conducted 24 hours, 72 hours and 30 days after treatment application, in order to study early response or a more sustained effect during time.
Project description:Humic substances have been widely used as plant growth promoters to improve the yield of agricultural crops. Root soluble protein profiles of 11 days after planting, cultivated with and without humic acids (50 mg C/L), were analysed using the label-free quantitative proteomic approach. The effects on root architecture, such as induction of lateral root and biomass increase were accompanied by changes in the proteins.
Project description:Climate change causes permafrost thawing, and we are confronted with the unpredictable risk of newly discovered permafrost microbes that have disease-causing capabilities. Here, we first characterized the detailed chemical structure of the lipid A moiety from a Pseudomonas species that was isolated from thawing arctic permafrost using MALDI-based mass spectrometric approaches (i.e., MALDI-TOF MS and MALDI-QIT-TOF MSn). The MALDI multi-stage mass spectrometry (MS) analysis of lipid A extracted from the Pseudomonas sp. strain PAMC 28618 demonstrated that the hexaacyl lipid A ([M-H]- at m/z 1616.5) contains a glucosamine (GlcN) disaccharide backbone, two phosphates, four main acyl chains and two branched acyl chains. Moreover, the lipid A molecule-based structural activity relationship with other terrestrial Gram-negative bacteria indicated that strain PAMC 28618 has an identical lipid A structure with the mesophilic Pseudomonas cichorii which can cause rot disease in endive (Cichorium endivia) and that their bacterial toxicities were equivalent. Therefore, the overall lipid A validation process provides a general strategy for characterizing bacteria that have been isolated from arctic permafrost and analyzing their respective pathogenicities.
Project description:The objective of the current study was to understand the glutaraldehyde resistance mechanisms in P. fluorescens and P. aeruginosa biofilms. Glutaraldehyde is a common biocide used in various industries to control the microbial growth. Recent reports of emergence of glutaraldehyde resistance in several bacterial species motivated this study to understand the genetic factors responsible got glutaraldehyde resistance. Using a combination of phenotypic assays, chemical genetic assays and RNA-seq, we demonstrate that novel efflux pump, polyamine biosynthesis, lipid biosynthesis and phosphonate degradation play significant role in glutaraldehyde resistance and post-glutaraldehyde recovery of Psudomonad biofilms.
