Northwest A&F University (Chinese: 西北农林科技大学; lit. 'Northwestern University of Agricultural and Forestry Science and Technology') is a national public research university in Xianyang, Shaanxi, China. The university is funded by the Ministry of Education. The university has an annual income of around RMB 1.72 billion (around £172 million) in 2011,. By April 2013, the university has 1661 faculty members and 28,964 students.
Although N-(2-chloro-4-pyridyl)-N '-phenylurea (CPPU) is widely used for kiwifruit enlargement, its effects on post-ripening quality remain unclear. This study integrated physiochemical and multi-omics analyses to investigate the impacts of CPPU on the quality of kiwifruit at harvest and after post-ripening. CPPU promoted fruit enlargement by expanding parenchyma cells, particularly small parenchyma cells, and enhanced uniformity in fruit appearance. CPPU increased pigment content, but suppressed starch accumulation resulting in lower total sugars in post-ripening fruit. Notably, CPPU might accelerate fruit softening by enhancing the activities of polygalacturonase, pectin lyase, and pectin methylesterase, as well as impairing the antioxidant system. CPPU also caused the loss of typical volatile esters (including benzoic acid ethyl ester and ethyl hexanoate), resulting in the dilution of flavor profiles in post-ripening fruit. Multi-omics analysis revealed that CPPU-mediated regulation of ripe fruit quality may be related to two aspects: inhibition of phenylpropanoid biosynthesis and the regulation of amino sugar and nucleotide sugar metabolism. These findings provide new insights into the potential mechanisms by which CPPU regulates the quality of 'Cuixiang' kiwifruit.
Green manures (GM) are widely used to mobilize legacy phosphorus (P), but how different GM species affect soil P fractions and microbial communities across P fertilization levels remain unclear. We investigated this question using a 7-year field experiment with a randomized complete block design. The experiment included two factors: (1) three cropping systems: fallow–winter wheat (FW), black bean–winter wheat (BW), and rapeseed–winter wheat (RW); and (2) three P application rates for winter wheat: 0 (P0), 80 (P80), and 160 (P160) kg P2O5 ha−1. Under P0 and P80, GM increased soil phosphatase activity by 4%–72% (P < 0.05), potentially enhancing NaHCO3-Po mineralization. In contrast, under P160, GM increased the organic (Po) and inorganic P (Pi) fractions by 7% and 5%, respectively. The RW system modified P fractions most effectively under P0 (labile P increased by 13%), whereas the BW system demonstrated superior benefits under P80 and P160 (labile P increased by 14% under both P80 and P160). GM altered soil microbial community composition and decreased α-diversity. The BW system selectively enriched putative P-solubilizing taxa, increasing the relative abundance of Burkholderia (bacteria) by 56% and that of Fusarium (fungi) by 44%, whereas the RW system increased the relative abundance of Burkholderia by 163% but decreased that of Fusarium by 21%. GM also increased the relative abundance of predicted P-cycling functional genes by 9%. Furthermore, GM cropping systems strengthened the topological structure of microbial networks (e.g., node and edge numbers increased by 37% and 76%, respectively). These changes promoted P transformation through higher soil phosphatase activity and lower pH. Overall, GM enhanced soil P availability under specific P levels by altering soil biochemical activities and regulating different P pools, providing a potential strategy for improving long-term P availability in agroecosystems.
Observed differences between paddy and upland croplands in soil organic carbon (SOC) and soil inorganic carbon (SIC) may reflect environmental and data-provenance imbalances rather than land-use effects. We reconstructed independent SOC and SIC profile datasets across China, harmonized depths, and separated fullsample comparisons from a prespecified comparable subset. Among all topsoil SOC profiles retained after applying the inclusion criteria (334 paddy, 347 upland), the median Upland-minus-Paddy contrast was -2.12 g kg- 1; within the shared subset (97/95), it attenuated to -0.35 g kg- 1 (95% interval, -1.74 to 1.55). For 97 paddy soils, changing only the land-use indicator to upland while holding observed soil and environment states fixed yielded a mean SOC contrast of -0.58 g kg- 1 (joint 95% interval, -1.02 to -0.15), with 78.4% negative. A layer-resolved Extra Trees S-learner supported this scenario with out-of-fold R2 = 0.72 and mean R2 = 0.72 across ten spatial partitions. The shared topsoil SIC subset retained only 9 paddy and 7 upland profiles, so adjusted SIC could not be estimated. Aridity index (AI) stratification showed the strongest negative SOC contrast in more humid high-AI croplands (-1.08 g kg- 1; -1.62 to -0.56), whereas low- and middle-AI strata crossed zero; the high-minus-middle difference was -1.29 g kg- 1 (-2.09 to -0.60). Among comparable croplands, observed topsoil SOC differed little between paddy and upland fields, but model predictions indicated lower SOC under upland land use, particularly in humid regions. These results suggest a modest SOC advantage of paddy croplands, while SIC differences remain unresolved.
Drought limits wheat production in dryland agroecosystems, yet native rhizosphere bacteria that improve drought tolerance under long-term field management remain insufficiently explored. We integrated high-throughput sequencing, co-occurrence network analysis, and culture-dependent isolation in a 20-year dryland field experiment with different nitrogen (N) addition and wheat genotypes to identify native culturable core bacteria and develop a drought-alleviating synthetic community (SynCom). N addition and wheat genotype altered the abundance of specific bacterial taxa, whereas treatment-driven differences in overall community structure were not detectable at the present replication level. N addition increased network complexity and reshaped bacterial co-occurrence patterns. By integrating 3320 shared ASVs, 597 keystone nodes, and 115 cultured isolates, we identified a culturable core microbiota comprising 9 ASVs. Four compatible strains (Pseudomonas piscicola, Curtobacterium allii, Acinetobacter oryzae, and Peribacillus frigoritolerans) enriched in drought-tolerant wheat were assembled into a SynCom. SynCom inoculation enhanced growth of drought-sensitive wheat seedlings across a simulated drought gradient, increasing root length by 113%−136%, belowground fresh weight by 93%−149%, and total dry weight by 31.75%−45.16%. These results support a microbiome-based strategy for improving wheat drought tolerance under controlled drought-simulation conditions.
