Project description:Phosphorus (P) limitation will play a key role in the productivity of agriculture in the coming decades. Struvite is an ammonium magnesium phosphate mineral that can be recovered from wastewater-treatment plants and can be considered as an alternative source of P. However, the impact of struvite on the plant yield and, particularly, on the soil microbial community is barely known. Here, we tested the impacts of struvite, sewage sludge, and their combination on the barley yield, soil macro and micronutrients, and biochemical and microbiological soil properties. Amendment with struvite alone and its combination with sludge increased the availability of P in soil, the plant uptake of P and Mg, and the barley yield. The analysis of phospholipid fatty acids (PLFAs) and metaproteomics approaches revealed significant effects of struvite on the biomass of Gram-positive bacteria and, particularly, on actinobacterial populations in soil.
Project description:Rhizosphere is a complex system of interactions between plant roots, bacteria, fungi and animals, where the release of plant root exudates stimulates bacterial density and diversity. However, the majority of the bacteria in soil results to be unculturable but active. The aim of the present work was to characterize the microbial community associated to the root of V. vinifera cv. Pinot Noir not only under a taxonomic perspective, but also under a functional point of view, using a metaproteome approach. Our results underlined the difference between the metagenomic and metaproteomic approach and the large potentiality of proteomics in describing the environmental bacterial community and its activity. In fact, by this approach, that allows to investigate the mechanisms occurring in the rhizosphere, we showed that bacteria belonging to Streptomyces, Bacillus and Pseudomonas genera are the most active in protein expression. In the rhizosphere, the identified genera were involved mainly in phosphorus and nitrogen soil metabolism.
Project description:The rapid expansion of fast-growing plantations in subtropical regions is closely linked to dry-season irrigation and fertilization; however, improper practices often lead to soil acidification and reduced nutrient bioavailability. Phosphorus (P), one of the most critical elements for plantation tree growth, shows complex spatial distribution patterns in soil that are influenced by multiple factors, directly affecting plantation productivity. This study investigated the effects of long-term fertilization and dry-season irrigation on the vertical distribution of phosphorus in an 8-year-old subtropical Eucalyptus plantation. This study employed stratified sampling (0–30 cm topsoil, 30–60 cm subsoil, 60–90 cm substratum) during dry seasons, coupled with metagenomics, metabolomics, and environmental factor analysis, to reveal vertical phosphorus cycling patterns and multiomics regulatory networks. Key findings: (1) Fertilization and dry-season irrigation had a limited influence on labile phosphorus and the diversity of P-cycling microorganisms. The topsoil presented significantly greater P availability than did the subsoil, manifested as elevated acid phosphatase activity (ACP), significant enrichment of the tryptophan metabolic pathway, and greater microbial diversity. (2) pH and the C:P ratio represent critical factors of vertical stratification in soil P cycling. Under acidic conditions, topsoil microorganisms facilitate P release via diverse metabolic pathways, whereas oligotrophic constraints in the substratum limit enzymatic activities. (3) We believe that potential cross-stratum microbial functional coordination exists in acidic soil P cycling, with linkages to tryptophan metabolism and polyP synthesis/degradation. Our study provides theoretical multiomics insights for optimizing the management of soil P pools in subtropical plantations under fertilization and dry-season irrigation.
Project description:The purpose of the present study is to determine the effect of Phosphorus deficiency on gene expression level using microarray analysis to identify genes responsible for root hair development. Phosphorus deficiency induced the formation of root hairs to explore a greater soil volume but molecular mechanisms were unknown. Therefore, microarray experiments were performed using root tips of Brassica carinata cultivars Bale and Bacho, respectively differing in root hair length during Phosphorus deficiency. Experimental design was carried out in nutrient solution in a climate chamber with controlled environmental conditions (20°C, 16h day/8h night cycle, 70% relative humidity) in a randomized design. 25 root tips from 10 day old seedlings grown without Phosphorus of 1cm length were harvested and immediately frozen in liquid nitrogen. Gene expression analyses were performed
Project description:Nipponbare performs poorly in phosphorus (P) deficient soil whereas a Nipponbare-derived NIL containing the Pup1 allele of donor parent Kasalath is tolerant to P deficiency. In this experiment we compared gene expression patterns in roots of this NIL to Nipponbare, grown either in a P deficient or P fertilized soil. The aim is to separate constitutive differences in expression from those induced by P deficiency. Keywords: genotype comparison, constitutive differential expression
2009-10-31 | GSE6187 | GEO
Project description:RHIZOSPHERE SOIL PHOSPHORUS AND DROUGHT-TOLERANT BACTERIA
Project description:OsPSTOL1 confers phosphorus (P)-deficiency tolerance in rice through enhancement of early root growth. The larger root surface area at early stage provides the plants an advantage for nutrient uptake. We conducted microarrays to determine the genes which are constitutively regulated by OsPSTOL1, independent of P supply and developmental stage. For Affymetrix microarrays, root RNA samples from IR64 35S::OsPSTOL1 plants (transgenic: T) and Nulls (non-transgenic: NT) grown in P-deficient soil +/- application of P fertilizer were used. Plants were at the reproductive/heading stage (- P treatment) and at mid-tillering (+P treatment), respectively.
Project description:The purpose of the present study is to determine the effect of Phosphorus deficiency on gene expression level using microarray analysis to identify genes responsible for root hair development. Phosphorus deficiency induced the formation of root hairs to explore a greater soil volume but molecular mechanisms were unknown. Therefore, microarray experiments were performed using root tips of Brassica carinata cultivars Bale and Bacho, respectively differing in root hair length during Phosphorus deficiency. Experimental design was carried out in nutrient solution in a climate chamber with controlled environmental conditions (20°C, 16h day/8h night cycle, 70% relative humidity) in a randomized design. 25 root tips from 10 day old seedlings grown without Phosphorus of 1cm length were harvested and immediately frozen in liquid nitrogen. Gene expression analyses were performed Results from xy microarrays are summarized in this study. The samples originate from roots of cultivars Bale and Bacho grown in Phosphorus deficient conditions. Microarrays were hybridized with Cy3 and Cy5 labeled cDNA from Bale and Bacho both during Phosphorus deficiency using a dye swap approach