Project description:In this experiment we measured the transcriptional response of tomato plants (cv “Money maker”) when attacked belowground by the nematode M. inognita and, subsequently, aboveground by different (and common for this crop) biotic agents. Three weeks-old plants were exposed to nematodes for 5 days. At the fifth day the terminal leaflet of one of the first two true leaves was infected with the Cauliflower Mosaic Virus, or with the pathogen, or with the potato aphid Macrosiphum euphorbiae, or with the CMV-infected M. euphorbiae. For each belowground/aboveground combination treatment a set of control plants that received only the aboveground treatment was prepared. The infected leaflets of 5 biological replicates, each consisting of 1 plant, were collected 1, 2, 3, 4, 5 and 6 days after the onset of the aboveground treatment and flash frozen in liquid nitrogen. A different set of plants was used for every time point. Corresponding leaves from plants that did not receive any aboveground treatment (control) were selected and sampled as described above. Three biological replicates were selected among the five for RNA isolation. Total RNA was sent for sequencing to BGI Hong Kong.
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.
2016-09-27 | GSE86527 | GEO
Project description:Simplification of soil communities impairs nutrient recycling and enhances above- and belowground nitrogen losses
| PRJNA648050 | ENA
Project description:Simplification of soil communities impairs nutrient recycling and enhances above- and belowground nitrogen losses