Project description:Increasing concern about pollution of our environment calls for advanced and rapid methods to estimate ecological toxicity. The use of gene expression microarrays in environmental studies can potentially meet this challenge. We present a novel method to examine soil toxicity. We exposed the collembolan Folsomia candida to soil containing an ecologically relevant cadmium concentration, and found a cumulative total of 1586 differentially expressed transcripts across three exposure durations, including transcripts involved in stress response, detoxification, and hypoxia. Additional enrichment analysis of gene ontology (GO) terms revealed that antibiotic biosynthesis is important at all time points examined. Interestingly, genes involved in the "penicillin and cephalosporin biosynthesis pathway" have never been identified in animals before, but are expressed in F. candida’s tissue. The synthesis of antibiotics can possibly be a response to increased cadmium-induced susceptibility to invading pathogens, which might be caused by repression of genes involved in the immune-system (C-type lectins and Toll receptor). This study presents a first global view on the environmental stress response of an arthropod species exposed to contaminated soil,and provides a mechanistic basis for the development of a gene expression soil quality test. Keywords: cadmium, soil, Collembola, environmental genomics
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: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%.