Project description:Bacterial endophytes were isolated from nodules of pea and faba bean. The strains were identified and characterized for plant beneficial activities (phosphate solubilisation, synthesis of indole acetic acid and siderophores) and salt tolerance. Based on these data, four strains of Rahnella aquatilis and three strains of Serratia plymuthica were considered as potential Plant Growth-Promoting Bacteria, able to support plant development in saline soils. In order to shed light on the mechanisms underlying salt tolerance, the proteome of the two most performant strains (Ra4 and Sp2) grown in presence or not of salt was characterized. The amount of protein expressed by the endophytes was higher in presence of salt. The modulated proteome was composed by 302 (100 up-regulated, 202 down-regulated) and by 323 (206 up-regulated, 117 down-regulated) in Ra4 and Sp2, respectively. Overall, proteins involved in abiotic stress responses were up-regulated, while those involved in metabolism and flagellum structure were down-regulated. The main up-regulated proteins in Sp2 was thiol:disulfide interchange protein DsbA, required for the sulphur binding formation in periplasmic proteins, while in Ra4 corresponded to the soluble fraction of ABC transporters, having a role in compatible solute uptake. Our results demonstrated a conserved response to salt stress in two taxonomically correlated species.
Project description:Biological nitrogen fixation (BNF) is a primary input of nitrogen to natural and agricultural systems globally. BNF is a temperature-dependant enzymatic process and can be conducted by microbes (including Rhizobia) hosted symbiotically in root nodules of some plants. Heat shock proteins (Hsps) have been implicated in the process of acquiring thermotolerance or acclimating to elevated temperature, as they play a vital role in maintaining cell integrity and homeostasis during heat stress. Although the BNF response to temperature may crucially impact future ecosystem productivity in the face of global climate change, little is known about Hsp expression in nodules of N-fixing non-agricultural species, such as tropical N-fixing trees in the Fabaceae family. This project aimed to characterize small (15-20kDa) Hsp (sHsp) expression in nodule tissue to examine the biochemical mechanisms of heat response in these tissues. To first identify Hsps in nodule tissues, Vachellia farnesiana and Acacia confusa nodules were excised, heat shock was induced, and protein content was isolated via chemical treatment before separation of protein species and analysis with SDS-PAGE. Two polyacrylamide gels yielded bands in the 15-20 kDa region that displayed differential Coomassie staining, which were sent for further characterization by HPLC-MS analysis for protein sequencing. Ten rhizobial sHsps were detected in these samples in addition to seven Acacia sHsps when compared independently to reference rhizobial and plant proteome databases. In an attempt quantify relative expression of Hsps in nodule and root tissue, we performed western blot experiments using Anti-Hsp20 antibodies raised against human and mouse Hsp proteins, with anti-beta actin loading control. While nonuniform beta-actin expression across tissue types (A. confusa nodules versus root control) prevented quantitative analysis, the experiments validated that Hsp20s are expressed in Acacia nodules as well as in root tissue. These experiments could provide a foundation for future studies that aim to determine variation in responses to key stressors predicted to increase with global climate change and help determine the implications of warming across the tropics and beyond.
2024-10-09 | PXD055599 | Pride
Project description:Isolation form Acacia root nodules
Project description:Gene expression profiles of Escherichia coli, grown anaerobically, with or without Acacia mearnsii (Black wattle) extract were compared to identify tannin-resistance strategies. The cell envelope stress protein, spy, and the multidrug transporter-encoding mdtABCD, both under the control of the BaeSR two-component regulatory system, were significantly up-regulated in the presence of tannins. BaeSR mutants were more tannin-sensitive than their wild-type counterparts. Keywords: tannin resistance
Project description:Two potato cultivars, Russet Burbank and Bionta, were inoculated with three different endophytes containing different AHL types. The impact of the endophytes to the different cultivars was measured by gene expression analysis with a customized microarray B. phytofirmans type strain PsJN was originally isolated as a contaminant from surface-sterilized, Glomus vesculiferum-infected onion roots (Nowak et al., 1998), whereas strain P6 RG6-12 was isolated from the rhizosphere of a grassland in the Netherlands (Salles et al., 2006). This strain was selected based on its similarity to strain PsJN based on 16S rRNA gene homology, and similar phenotypic features. Both strains were generally cultivated on King's medium (King et al., 1954). For the mutant AHL to the strain B. phytofirmans PsJN a quorum quenching approach as described by Wopperer et al., 2006 was employed. Plasmid pMLBAD-aiiA, which contains aiiA, the Bacillus sp. 240B1 lactonase gene, was transferred to B. phytofirmans PsJN by triparental mating as described by de Lorenzo and Timmis (1994). 2 cultivars, 3 endophytes
Project description:Two potato cultivars, Russet Burbank and Bionta, were inoculated with three different endophytes containing different AHL types. The impact of the endophytes to the different cultivars was measured by gene expression analysis with a customized microarray
Project description:We seek to determine the effects of foliar endophytes on soybean physiological traits, and their effect on plant responses to elevated carbon dioxide. We are using three dominant endophytes extracted from the SoyFACE facility at UIUC.
2025-04-04 | GSE200235 | GEO
Project description:Bradyrhizobium spp. isolated from Acacia saligna nodules in Tunisia