ABSTRACT: Effect of nitrogen fertilizer reduction and organic amendment on soil bacterial and fungal communities in a N-overfertilized wheat-maize cropping system
Project description:The spread of antibiotic resistance genes (ARG) into agricultural soils, products, and foods severely limits the use of organic fertilizers in agriculture. In this study, experimental land plots were fertilized, sown, and harvested for two consecutive agricultural cycles using either mineral or three types of organic fertilizers: sewage sludge, pig slurry, or composted organic fraction of municipal solid waste. The analysis of the relative abundances of more than 200,000 ASV (Amplicon Sequence Variants) allowed the identification of a small, but significant (<10%) overlap between soil and fertilizer microbiomes, particularly in soils sampled the same day of the harvest (post-harvest soils). Loads of clinically relevant ARG were significantly higher (up to 100 fold) in fertilized soils relative to the initial soil. The highest increases corresponded to post-harvest soils treated with organic fertilizers, and they correlated with the extend of the contribution of fertilizers to the soil microbiome. Edible products (lettuce and radish) showed low, but measurable loads of ARG (sul1 for lettuces and radish, tetM for lettuces). These loads were minimal in mineral fertilized soils, and strongly dependent on the type of fertilizer. We concluded that at least part of the observed increase on ARG loads in soils and foodstuffs were actual contributions from the fertilizer microbiomes. Thus, we propose that adequate waste management and good pharmacological and veterinarian practices may significantly reduce the potential health risk posed by the presence of ARG in agricultural soils and plant products.
Project description:Two maize hybrid cultivars contrasting in low nitrogen tolerance (low nitrogen-tolerant XY335 and low nitrogen-sensitive HN178) were used in this study . The experiment was carried out at Xinji Experimental Station (43º31′N, 124º48′E) of Hebei Agricultural University. The top 0-20 cm of the soil used contained organic matter 17.79 g·kg-1, total nitrogen 1.21 g·kg-1, alkali hydrolyzed nitrogen 64.9 mg.kg-1, available phosphorus 23.8 mg·kg-1, and available potassium 120.6 mg·kg-1. The experiment adopted a split plot design, with varieties as the main plot and nitrogen fertilizer as the sub-plot. There were 2 varieties for testing: XY335 and HN138. Two levels of nitrogen supply: N0 (0 kg N ha-1) and N240 (240 kg N ha-1), replicated three times. Each plot had 6 rows, with the row length measuring 20 m, and the row spacing of 60 cm, giving the plot area of 72 m2. The planting density was 67,500 plants ha-1. Nitrogen fertilizer used was urea (46% N), and 50% was applied before sowing and at the flared stage, respectively. During the grain filling stage, leaf tissues of three biological replicates were collected from control and treatment conditions, and immediately frozen in liquid nitrogen for subsequent proteomics analysis.
Project description:Among the mineral elements necessary for plant growth, nitrogen (N) is the macronutrient required in larger amounts. The optimization of N use efficiency (NUE) in maize could be obtained through both genetic improvement and agronomic practices in order to enhance production and reduce the negative impact of the N fertilizer use on the environment. Physiological characterizations of inbred lines with different NUE are available in maize.
Project description:We used wheat as rotational crop to assess the influence of continuous cropping on microbiome in Pinellia ternata rhizosphere and the remediation of rotational cropping to the impacted microbiota. Illumina high-throughput sequencing technology was utilized for this method to explore the rhizosphere microbial structure and diversity based on continuous and rotational cropping.
Project description:Effect of nitrogen supply and nitrogen supply form on the transcriptome of wheat grain. Differences reflecting the use of inorganic versus organic fertiliser regimes.
Project description:Nitrate is the limiting nitrogen nutrient enabling photosynthetic plants to support the conversion of inorganic elements to organic biomass, which sustains all lives. Plants evolved multifaceted nitrate responses to modulate global gene expression, metabolism and developmental programs. However, primary nitrate signaling mechanisms remained elusive. Using an ultrasensitive Ca2+ biosensor, unique nitrate-induced Ca2+ signaling was illuminated in Arabidopsis cells and plants. Integrative functional genomic screens, chemical genetics, genome-wide transcript sequencing, and analyses of nitrate-associated traits uncovered the surprising roles of Ca2+ sensor protein kinases (CPKs) in orchestrating diverse primary and long-term nitrate responses. Nitrate specifies CPK signaling to reprogram transcriptome and govern N-assimilation, metabolism, transport, hormones, shoot growth, and root system architecture. CPKs may be targeted to enhance nitrogen-use-efficiency, reduce fertilizer demands, and alleviate ecosystem pollution.
Project description:Development of crop varieties with high nitrogen use efficiency (NUE) is crucial for minimizing N loss, reducing environmental pollution and decreasing input cost. Maize is one of the most important crops cultivated worldwide and its productivity is closely linked to the amount of fertilizer used. A survey of the transcriptomes of shoot and root tissues of a maize hybrid line and its two parental inbred lines grown under sufficient and limiting N conditions by mRNA-Seq has been conducted to have a better understanding of how different maize genotypes respond to N limitation.
Project description:Wheat (Triticum aestivum), one of the most important cereal crops, it provides many kinds of food for humans and animals, in this study, we performed the first comprehensive phosphoproteome analysis to study the regulatory mechanism of bread quality formation under different nitrogen fertilizer. Totally, 2470 phosphotides, represented 1372 proteins were identified in our study. and 411 proteins showed significant differences.
Project description:Comparison of the transcriptome profiles of a widely commercialized maize variety (Helen) at two levels of nitrogen fertilization. Conventional nitrogen fertilization compared to not nitrogen fertilization during the season.
