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IntroductionDrip irrigation under mulch film promotes a non-uniform salinity distribution in salt fields. The effect of different N application methods on the growth and yield of cotton under drip irrigation under mulch film conditions in eastern coastal saline-alkaline soils in China remain remained unclear.MethodsA randomized complete block design was used in the experiment. Three N application methods were assigned: N applied under mulch film (low-salinity area; UM), N applied between mulch films (high-salinity area; BM), and half N applied under mulch film and half between mulch films (HUHB).ResultsPlant height, photosynthesis, Chl content, boll load, biomass, boll weight and boll density under UM were all significantly higher than those under the other two treatments. The N absorption of UM was higher than in the other two treatments, which might be attributed to the expression of GHNRT1.5 and GHNRT2.1. The net NO3- influx in the roots in UM increased significantly compared with that in BM. The yield and FNRE of UM were 3.9% and 9.1%, respectively, and were 26.52% and 90.36% higher than under HUHB and BM treatments.DiscussionUM not only improved cotton yield but also alleviated the pollution of N residue on drip irrigation under mulch film conditions in salt areas.

Agricultural chemicals are commonly used to control pests and weeds, but cause pesticide waste problems. Oil-based emulsions are often used as pesticide formulations to improve pesticide utilization. In this study, the spray visualization experiment of the water and oil-based emulsion butachlor is carried out using an ST flat fan nozzle at 0.1–0.5 MPa pressure. The dimensionless method is used to analyze the difference in liquid sheet fragmentation morphology and disintegration process and the influence of different fragmentation methods on droplet size. It is found that the hydrophobic components in pesticide have a significant effect on the morphology and process of atomization fragmentation. When spray liquid is water, the liquid sheet breaks up into liquid ligaments due to the Rayleigh instability, then the ligaments break up into droplets. The side view of a liquid sheet is a large-amplitude wave disturbance. When the spray liquid is the emulsion butachlor, holes are generated on the liquid sheet, then the holes break up into droplets. The fragmentation method of emulsion spray is the perforation mechanism. Compared with water spray, the presence of the pesticide butachlor increases the droplet size and spray angle and improves the uniformity of droplet size distribution but reduces the breakup length. The spray angle shows a power law dependence of the Weber number with a power of 0.17 for all conditions tested here. At 0.3 MPa, DV50 increases 25%, and span decreases from 1.187 to 1.172. This study could provide reference for the addition of agricultural additives, the improvement of spray operation efficiency, and the establishment of spray fragmentation mechanism.

Peroxisomes are ubiquitous eukaryotic organelles housing not only many important oxidative metabolic reactions, but also some reductive reactions that are less known. Members of the short-chain dehydrogenase/reductase (SDR) superfamily, which are NAD(P)(H)-dependent oxidoreductases, play important roles in plant peroxisomes, including the conversion of indole-3-butyric acid (IBA) to indole-3-acetic acid (IAA), auxiliary β-oxidation of fatty acids, and benzaldehyde production. To further explore the function of this family of proteins in the plant peroxisome, we performed an in silico search for peroxisomal SDR proteins from Arabidopsis based on the presence of peroxisome targeting signal peptides. A total of 11 proteins were discovered, among which four were experimentally confirmed to be peroxisomal in this study. Phylogenetic analyses showed the presence of peroxisomal SDR proteins in diverse plant species, indicating the functional conservation of this protein family in peroxisomal metabolism. Knowledge about the known peroxisomal SDRs from other species also allowed us to predict the function of plant SDR proteins within the same subgroup. Furthermore, in silico gene expression profiling revealed strong expression of most SDR genes in floral tissues and during seed germination, suggesting their involvement in reproduction and seed development. Finally, we explored the function of SDRj, a member of a novel subgroup of peroxisomal SDR proteins, by generating and analyzing CRISPR/Cas mutant lines. This work provides a foundation for future research on the biological activities of peroxisomal SDRs to fully understand the redox control of peroxisome functions.

In situ conserved wild rice (Oryza rufipogon Griff.) is a promising source of alleles for improving rice production worldwide. In this study, we conducted a genomic analysis of an in situ conserved wild rice population (Guiping wild rice) growing at the center of wild rice genetic diversity in South China. Differences in the plant architecture in this population were investigated. An analysis using molecular markers revealed the substantial genetic diversity in this population, which was divided into subgroups according to the plant architecture. After resequencing representative individuals, the Guiping wild rice population was compared with other O. rufipogon and Oryza sativa populations. The results indicated that this in situ conserved wild rice population has a unique genetic structure, with genes that were introgressed from aromatic and O. sativa ssp. indica and japonica populations. The QTLs associated with plant architecture in this population were detected via a pair-wise comparison analysis of the sequencing data for multiple DNA pools. The results suggested that a heading date-related gene (DHD1) might be associated with variations in plant architecture and may have originated in cultivated rice. Our findings provide researchers with useful insights for future genomic analyses of in situ conserved wild rice populations.

Moderate curling generally causes upright leaf blades, which favors the establishment of ideal plant architecture and increases the photosynthetic efficiency of the population, both of which are desirable traits for super hybrid rice (Oryza sativa L.). In this study, we identified a novel curled-leaf mutant, curled flag leaf 2 (cfl2), which shows specific curling at the base of the flag leaf owing to abnormal epidermal development, caused by enlarged bulliform cells and increased number of papillae with the disordered distribution. Map-based cloning reveals that CFL2 encodes a cytochrome P450 protein and corresponds to the previously reported OsCYP96B4. CFL2 was expressed in all analyzed tissues with differential abundance and was downregulated in the clf1 mutant [a mutant harbors a mutation in the homeodomain leucine zipper IV (HD-ZIP IV) transcription factor Roc5]. Yeast one-hybrid and transient expression assays confirm that Roc5 could directly bind to the cis-element L1 box in the promoter of CFL2 before activating CFL2 expression. RNA sequencing reveals that genes associated with cellulose biosynthesis and cell wall-related processes were significantly upregulated in the cfl2 mutant. The components of cell wall, such as lignin, cellulose, and some kinds of monosaccharide, were altered dramatically in the cfl2 mutant when compared with wild-type “Jinhui10” (WT). Taken together, CFL2, as a target gene of Roc5, plays an important role in the regulation of flag leaf shape by influencing epidermis and cell wall development.