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Wheat growth and nitrogen (N) uptake gradually decrease in response to high NH4+/NO3– ratio. However, the mechanisms underlying the response of wheat seedling roots to changes in NH4+/NO3– ratio remain unclear. In this study, we investigated wheat growth, transcriptome, and proteome profiles of roots in response to increasing NH4+/NO3– ratios (N a : 100/0; N r 1: 75/25, N r 2: 50/50, N r 3: 25/75, and N n : 0/100). High NH4+/NO3– ratio significantly reduced leaf relative chlorophyll content, Fv/Fm, and ΦII values. Both total root length and specific root length decreased with increasing NH4+/NO3– ratios. Moreover, the rise in NH4+/NO3– ratio significantly promoted O2– production. Furthermore, transcriptome sequencing and tandem mass tag-based quantitative proteome analyses identified 14,376 differentially expressed genes (DEGs) and 1,819 differentially expressed proteins (DEPs). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that glutathione metabolism and phenylpropanoid biosynthesis were the main two shared enriched pathways across ratio comparisons. Upregulated DEGs and DEPs involving glutathione S-transferases may contribute to the prevention of oxidative stress. An increment in the NH4+/NO3– ratio induced the expression of genes and proteins involved in lignin biosynthesis, which increased root lignin content. Additionally, phylogenetic tree analysis showed that both A0A3B6NPP6 and A0A3B6LM09 belong to the cinnamyl-alcohol dehydrogenase subfamily. Fifteen downregulated DEGs were identified as high-affinity nitrate transporters or nitrate transporters. Upregulated TraesCS3D02G344800 and TraesCS3A02G350800 were involved in ammonium transport. Downregulated A0A3B6Q9B3 is involved in nitrate transport, whereas A0A3B6PQS3 is a ferredoxin-nitrite reductase. This may explain why an increase in the NH4+/NO3– ratio significantly reduced root NO3–-N content but increased NH4+-N content. Overall, these results demonstrated that increasing the NH4+/NO3– ratio at the seedling stage induced the accumulation of reactive oxygen species, which in turn enhanced root glutathione metabolism and lignification, thereby resulting in increased root oxidative tolerance at the cost of reducing nitrate transport and utilization, which reduced leaf photosynthetic capacity and, ultimately, plant biomass accumulation. [ABSTRACT FROM AUTHOR]

Optimal sowing depth plays an important role in peanut's stand establishment and yield. A field experiment was conducted to investigate sowing depths effects (3 cm, SD3; 5 cm, SD5; 7 cm, SD7; 9 cm, SD9; 11 cm, SD11; 13 cm, SD13; 15 cm, SD15) on soil environments, hypocotyl growth, endogenous hormones content, and pod yield. Both shallow- (3 cm) and deep-sowing (15 cm) treatments decreased the pod yield due to plant and pod number lowering that resulted from decreased seedling emergence rate (SER). SD3 treatment possessed less soil water content (SWC) that led to lowered SER. Soil penetration resistance (SPR) was significantly increased with sowing depths that resulted in SER decrease and delayed emergence time. Compared with the SD5 treatment, the SER was 15.7% and 16.6% lower in SD15 treatment in the 2017 and 2018 season, respectively. SD5 and SD15 took 111.1 and 161.5 day-degrees (°Cd), respectively; to attain maximum length. Further, sowing depth increase resulted in elevated cotyledon's lipase activities, endogenous auxin (IAA) and gibberellin (GA3) contents, and hypocotyl dry weight. However, decreased cotyledon weight implied that hypocotyl growth of deep-sowing exhausted the stored nutrition by increasing endogenous GA3 and IAA, to sustain its emergence above the soil. [ABSTRACT FROM AUTHOR]

Wheat growth and nitrogen (N) uptake gradually decrease in response to high NH 4 + /NO 3 - ratio. However, the mechanisms underlying the response of wheat seedling roots to changes in NH 4 + /NO 3 - ratio remain unclear. In this study, we investigated wheat growth, transcriptome, and proteome profiles of roots in response to increasing NH 4 + /NO 3 - ratios (N a : 100/0; N r 1 : 75/25, N r 2 : 50/50, N r 3 : 25/75, and N n : 0/100). High NH 4 + /NO 3 - ratio significantly reduced leaf relative chlorophyll content, Fv/Fm, and ΦII values. Both total root length and specific root length decreased with increasing NH 4 + /NO 3 - ratios. Moreover, the rise in NH 4 + /NO 3 - ratio significantly promoted O 2 - production. Furthermore, transcriptome sequencing and tandem mass tag-based quantitative proteome analyses identified 14,376 differentially expressed genes (DEGs) and 1,819 differentially expressed proteins (DEPs). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that glutathione metabolism and phenylpropanoid biosynthesis were the main two shared enriched pathways across ratio comparisons. Upregulated DEGs and DEPs involving glutathione S-transferases may contribute to the prevention of oxidative stress. An increment in the NH 4 + /NO 3 - ratio induced the expression of genes and proteins involved in lignin biosynthesis, which increased root lignin content. Additionally, phylogenetic tree analysis showed that both A0A3B6NPP6 and A0A3B6LM09 belong to the cinnamyl-alcohol dehydrogenase subfamily. Fifteen downregulated DEGs were identified as high-affinity nitrate transporters or nitrate transporters. Upregulated TraesCS3D02G344800 and TraesCS3A02G350800 were involved in ammonium transport. Downregulated A0A3B6Q9B3 is involved in nitrate transport, whereas A0A3B6PQS3 is a ferredoxin-nitrite reductase. This may explain why an increase in the NH 4 + /NO 3 - ratio significantly reduced root NO 3 - -N content but increased NH 4 + -N content. Overall, these results demonstrated that increasing the NH 4 + /NO 3 - ratio at the seedling stage induced the accumulation of reactive oxygen species, which in turn enhanced root glutathione metabolism and lignification, thereby resulting in increased root oxidative tolerance at the cost of reducing nitrate transport and utilization, which reduced leaf photosynthetic capacity and, ultimately, plant biomass accumulation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Yang, Zhao, Bi, Li and Wang.)

Herein, a split-type immunoassay strategy instigated by cation exchange (CE) and changing the capacity of an electron donor in an electrolyte solution is optimized, namely, for differentiating the biological-specific binding assay and photoelectrochemical (PEC) analysis. MoSe 2 /CdSe, a Z-scheme heterojunction with efficient visible light absorption and a low recombination of carriers, is used as a photoelectrode substrate. Silver ions (Ag + ) as the initiator of CE are generated by the acidolysis of evenly loaded silver nanoparticles on mesoporous silica nanospheres (MSNs). The theoretical calculation and experimental results confirm that Ag + replaces Cd 2+ in CdSe and retains the crystal structure of MoSe 2 . However, this behavior destroys the perfectly matched heterojunction structure and introduces defects, which led to the reduction of the photocurrent response. In addition, ascorbate oxidase in combination with MSNs can be used as a consumptive agent of the electron donor, which further improves the sensitivity and reliability of the sensor. As a proof of principle, neuron-specific enolase was applied to elucidate the potential application of the PEC immunoassay in clinical diagnosis, and the obtained linear range of the sensor was from 0.0001 to 100 ng/mL with a detection limit of 28 fg/mL (S/N = 3).

Decoration of noble metals with transition-metal oxides has been intensively studied for heterogeneous catalysis. However, controllable syntheses of metal-metal oxide heterostructures are difficult, and elucidation of such interfaces is still challenging. In this work, supported IrCo alloy nanoparticles are transformed into supported Ir-CoO x close-contact nanostructures by in situ calcination and following selective reduction. Relative to Ir/Al 2 O 3 , Ir-CoO x /Al 2 O 3 shows greatly enhanced activities for the hydrogenation of furfural derivatives to the corresponding furfuryl alcohol derivatives with more than 99% selectivity and demonstrates significantly improved activities and selectivity for hydrogenations of α,β-unsaturated aldehydes to α,β-unsaturated alcohols. The modification of Ir surfaces with CoO x prevents Ir nanoparticles from growing, achieving high thermal and catalytic stabilities. Theoretic calculation suggests that the better catalytic performance of Ir-CoO x /Al 2 O 3 is ascribed to the Ir-CoO x interaction, which promotes the absorption of furfural as well as desorption of furfuryl alcohol, resulting in enhanced catalytic activities.

Bimolecular nucleophilic substitution (S N 2) reactions are of great importance in chemistry and biochemistry due to their capability of constructing functional groups. In this work, we investigate the solvent effect on the free energy profiles of symmetric and asymmetric S N 2 reactions in the acetonitrile solution using the proposed reaction density functional theory (RxDFT) method. This multiscale method utilizes quantum density functional theory for calculating intrinsic reaction free energy coupled with classical density functional theory for addressing solvation contribution. We find that the presence of acetonitrile brings both the polarization effect and solvation effect on the reaction pathways. For the eight selected symmetric S N 2 reactions, the predicated reaction pathways agree well with the results from the direct and thermodynamic cycle (TC) methods with the SMD-M062X solvation model. In addition, the polarization effect reduces the free energy barriers by about 6 kcal/mol, while the solvation effect increases the barriers by about 18 kcal/mol. For the four selected asymmetric S N 2 reactions, the predicted reaction pathways agree well with the results from the Monte Carlo simulations and experiments. The polarization effect and the solvation effect mutually reduce the free energy barriers, and the solvation effect plays a dominant role.