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:Background: The soil environment is responsible for sustaining most terrestrial plant life on earth, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere and how it responds to agricultural management such as crop rotations and soil tillage will be vital for improving global food production. Methods: The rhizosphere soils of wheat and chickpea growing under + and - decaying root were collected for metagenomics sequencing. A gene catalogue was established by de novo assembling metagenomic sequencing. Genes abundance was compared between bulk soil and rhizosphere soils under different treatments. Conclusions: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the microbiome from decaying root in determining the metagenome of developing root systems, which is fundamental to plant growth, since roots preferentially inhabit previous root channels. Modifications in root microbial function through soil management, can ultimately govern plant health, productivity and food security.
Project description:Fire is a crucial event regulating the structure and functioning of many ecosystems. Yet few studies focused on how fire affects both the taxonomic and functional diversity of soil microbial communities, along with plant diversity and soil carbon (C) and nitrogen (N) dynamics. Here, we analyze these effects for a grassland ecosystem 9-months after an experimental fire at the Jasper Ridge Global Change Experiment (JRGCE) site in California, USA. Fire altered soil microbial communities considerably, with community assembly process analysis indicating that environmental selection pressure was higher in burned sites. However, a small subset of highly connected taxa were able to withstand the disturbance. In addition, fire decreased the relative abundances of most genes associated with C degradation and N cycling, implicating a slow-down of microbial processes linked to soil C and N dynamics. In contrast, fire stimulated plant growth, likely enhancing plant-microbe competition for soil inorganic N. To synthesize our findings, we performed structural equation modeling, which showed that plants but not microbial communities were responsible for the significantly higher soil respiration rates in burned sites. In conclusion, fire is well-documented to considerable alter the taxonomic and functional composition of soil microorganisms, along with the ecosystem functioning, thus arousing feedback of ecosystem responses to affect global climate.
Project description:Take-all is a devastating soil-borne disease that affects wheat production. The continuous generation of disease-resistance germplasm is an important aspect of the management of this pathogen. In this study, we characterized the wheat-Psathyrostachys huashania Keng-derived progeny H139 that exhibits significantly improved resistance to wheat take-all disease compared with its susceptible parent 7182. GISH) and mc-FISH analyses revealed that H139 is a stable wheat-P. huashania disomic substitution line lacking wheat chromosome 2D.EST-STS marker and Wheat Axiom 660K Genotyping Array analysis further revealed that H139 was a novel wheat-P. huashania 2Ns/2D substitution line, and that the P. huashania 2Ns chromosome shares high sequence similarity to wheat chromosome 2D. These results indicate that H139, with its enhanced wheat take-all disease resistance and desirable agronomic traits, provides valuable genetic resources for wheat chromosome engineering breeding.
2020-01-07 | GSE143188 | GEO
Project description:Negative plant soil feedback influences plant community development in grassland restoration
Project description:We present metaproteome data from wheat rhizosphere from saline and non-saline soil. For collection and acquisition of metaproteome from wheat rhizosphere under saline and normal conditions, a survey was conducted in regions of Haryana, India. Samples from 65 days old plants (wheat var HD2967) were collected and pooled and based on EC,saline (NBAIM B; EC 6mS cm-1; pH 9.0; Bhaupur 2, Haryana, INDIA; 29°19'8"N;76°48'53"E) and normal soil samples (NBAIM C; EC 200 uS cm-1; pH 7.2; Near Nainform, Haryana, INDIA; 29°19'8"N;76°48'53"E) were selected for isolation of proteome with the standardized protocol at our laboratory followed by metaproteome analysis with the standardized pipepline. In total 1538 and 891 proteins were obtained from wheat rhizosphere from saline and non-saline respectively with the given parameters and software. Among 1410 proteins unique for saline soil, proteins responsible for glycine, serine and threonine metabolism and arginine and proline biosynthesis were found in saline and absent in non-saline. The present study extends knowledge about the physiology and adaptations of the wheat rhizosphere associated microbiota under saline soil.
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:MicroRNAs (miRNAs) are small non-coding RNAs that regulate target mRNAs by inducing degradation or preventing translation of their target mRNAs. Winter wheat, Triticum aestivum., is an important crop plant, yet there are only a few studies on the association of miRNAs and growth and development of winter wheat grown in the field. Here we carried out experimental analysis of miRNAs in wheat leaves by analyzing small RNA profiles at different growth stages.