Project description:rs11-07_opine2 - septante soil - Transcriptomic changes induced by opine production in Arabidopsis thaliana grown in natural soil - Arabidopsis thalian Col- line was transformed in order to obtain transgenic lines that produce opine compound (octopine and mannopine). Transgenic lines producing respectively octopine and mannopine and the WT line were grown in greenhouse under long-day condition in pots containing half commercial compost and half soil of la Mérantaise and watered with water. Whole plant aged of one month were harvested and frozen in liquid nitrogen. The plants were ground with a mortar an pestls and RNA extraction was performed with the RNeasy extraction kit (QIAGEN) with cristal of PVP. The RNA concentration was measured on a NANODrop spectrophotometer.
Project description:Understanding the mechanisms underlying the establishment of invasive plants is critical in community ecology. According to a widely accepted theory, plant-soil-microbe interactions mediate the effects of invasive plants on native species, thereby affecting invasion success. However, the roles and molecular mechanisms associated with such microbes remain elusive. Using high throughput sequencing and a functional gene microarray, we found that soil taxonomic and functional microbial communities in plots dominated by Ageratina adenophora developed to benefit the invasive plant. There were increases in nitrogen-fixing bacteria and labile carbon degraders, as well as soil-borne pathogens in bulk soil, which potentially suppressed native plant growth. Meanwhile, there was an increase of microbial antagonism in the A. adenophora rhizosphere, which could inhibit pathogenicity against plant invader. These results suggest that the invasive plant A. adenophora establishes a self-reinforcing soil environment by changing the soil microbial community. It could be defined as a ‘bodyguard/mercenary army’ strategy for invasive plants, which has important insights for the mitigation of plant invasion.
Project description:Clipping (i.e., harvesting aboveground plant biomass) is common in agriculture and for bioenergy production. However, microbial responses to clipping in the context of climate warming are poorly understood. We investigated the interactive effects of grassland warming and clipping on soil properties, plant and microbial communities, in particular microbial functional genes. Clipping alone did not change the plant biomass production, but warming and clipping combined increased the C4 peak biomass by 47% and belowground net primary production by 110%. Clipping alone and in combination with warming decreased the soil carbon input from litter by 81% and 75%, respectively. With less carbon input, the abundances of genes involved in degrading relatively recalcitrant carbon increased by 38-137% in response to either clipping or the combined treatment, which could weaken the long-term soil carbon stability and trigger a positive feedback to warming. Clipping alone also increased the abundance of genes for nitrogen fixation, mineralization and denitrification by 32-39%. The potentially stimulated nitrogen fixation could help compensate for the 20% decline in soil ammonium caused by clipping alone, and contribute to unchanged plant biomass. Moreover, clipping tended to interact antagonistically with warming, especially on nitrogen cycling genes, demonstrating that single factor studies cannot predict multifactorial changes. These results revealed that clipping alone or in combination with warming altered soil and plant properties, as well as the abundance and structure of soil microbial functional genes. The aboveground biomass removal for biofuel production needs to be re-considered as the long-term soil carbon stability may be weakened.
Project description:Arabidopsis plants were grown in plastic pots filled with peat moss for 3 weeks (principal growth stage 1.07-1.08) under a 16 h light/8 h dark regimen (40 ± 10 ?mol photons/m2/s) at 22 C.Dehydration treatment: The 3-week-old plants were grown for 2 or 3 days without watering. To obtain accurate results, we carefully raised single plants in Petri dishes, each containing an equal amount of soil. Soil moisture contents were calculated from soil dry weight. Untreated; the soil moisture content was 84.3%. Under dehydration, on the second day, the soil moisture content was 51.1%. Under dehydration, on the third day, the moisture content was 11.6%.