Project description:Forming symbiotic associations with beneficial microbes are important strategies for sessile plants to acquire nitrogen and phosphorus nutrients from the soil. Root exudates play key roles on set-up of the rhizosphere microbiome. According to the needs for nitrogen or phosphorus, plants can adjust the root exudates composition to attract proper microbes. Flavonoids are a group of secondary metabolites that are well studied in shaping the root microbiome, especially the root nodule symbiosis in legumes. Here, we show the medicago truncatula phosphate sensors SPX1 and SPX3 regulate flavonoids biosynthesis to recruit nitrogen-fixing microbes for nitrogen acquisition. Nitrogen-fixing microbes were less recruited in spx1spx3 double mutant root rhizosphere. This was caused by lower flavonoids biosynthesis related genes expression, which resulted in lower flavonoids levels in the root exudates compared to wild type plant R108. Further analysis indicates the regulation of flavonoids biosynthesis is through the SPX1 and SPX3 interaction transcription factor PHR2. We propose the SPX-PHR phosphate homeostasis regulation network also control microbe-dependent nitrogen acquisition according to phosphate levels. Thus, SPX1 and SPX3 play important roles to keep a microbe-dependent nitrogen and phosphorus absorption balance for optimal growth.
Project description:Plants and rhizosphere microbes rely closely on each other, with plants supplying carbon to bacteria in root exudates, and bacteria mobilizing soil-bound phosphate for plant nutrition. When the phosphate supply becomes limiting for plant growth, the composition of root exudation changes, affecting rhizosphere microbial communities and microbially-mediated nutrient fluxes. To evaluate how plant phosphate deprivation affects rhizosphere bacteria, Lolium perenne seedlings were root-inoculated with Pseudomonas aeruginosa 7NR, and grown in axenic microcosms under different phosphate regimes (330 uM vs 3-6 uM phosphate). The effect of biological nutrient limitation was examined by DNA microarray studies of rhizobacterial gene expression.
Project description:Long-term dietary intake influences the structure and activity of the trillions of microorganisms residing in the human gut, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles. RNA-Seq analysis of the human gut microbiome during consumption of a plant- or animal-based diet.
Project description:Here, we examine the transcriptomic response of adult wild-type and BrphyB leaves to darkening and recovery in light. Three days of dark was sufficient to elicit a response in wild type leaves suggesting a shift from carbon fixation and nutrient acquisition to active redistribution of cellular resources. Upon a return to light, wild-type leaves appeared to transcriptionally return to a pre-darkness state restoring a focus on nutrient acquisition. BrphyB mutant plants have a similar response with key differences in genes involved in photosynthesis and light response which deviate from the wild type transcriptional dynamics. Genes targeted to the chloroplast are especially affected. Adult plants had fewer, larger chloroplasts suggesting a link between phytochromes, chloroplast development, photosynthetic deficiencies and resource allocation.
2020-08-18 | GSE135955 | GEO
Project description:Transcrptome of (proto-)carnivorous plants in Ericales