Soybeans, a crucial grain and oil crop, are valued for their high protein and oil content.  Soil salinization is a significant abiotic stress that negatively impacts soybean growth and development, resulting in reduced yield and quality.  The germination period represents a critical phase in soybean development.  This study evaluated salt tolerance in 165 soybean mutant lines during germination, identifying five elite salt-tolerant germplasm resources.  Multi-environment genome-wide association studies (GWASs) identified 11 significantly associated and 44 suggestive single nucleotide polymorphisms, alongside five novel quantitative trait loci linked to salt tolerance.  Analysis of candidate regions qtl5-1 and qtl5-2 identified Glyma.05G097200 and Glyma.05G240200 as promising candidate genes, exhibiting distinct expression patterns between salt-tolerant and -sensitive genotypes.  Functional characterization in Arabidopsis demonstrated that overexpression of the soybean gene GmMACPF1 induced salt sensitivity, while the macpf1 mutant of Arabidopsis displayed enhanced salt tolerance.  Additionally, GmMACPF1 underwent selection during soybean domestication, with haplotypes Hap1 and Hap3 conferring improved salt tolerance.  These results indicate that GmMACPF1 functions as a negative regulator of salt tolerance during germination, offering novel insights into the molecular mechanisms governing soybean response to salt stress during this crucial developmental stage.

The universal stress proteins (USPs) play important roles not only in abiotic stress tolerance but also in plant growth and development.  However, the role of USPs in regulating starch biosynthesis has not been reported.  In this study, the IbUSP17 gene was isolated from the sweetpotato line H283 with a high starch content.  The IbUSP17 protein was localized in the nucleus.  IbUSP17 was highly expressed in lines with high starch contents and during the rapid thickening and starch accumulation period of storage roots.  Overexpressing IbUSP17 increased the storage root starch content, especially the amylopectin proportion, without a storage root yield penalty in sweetpotato.  Overexpression of IbUSP17 up-regulated the genes involved in starch biosynthesis and increased the activities of enzymes related to amylopectin biosynthesis.  The contents of components related to starch biosynthesis were also increased in IbUSP17-overexpressing plants.  Silencing this gene produced the opposite effects.  These results suggest that overexpression of IbUSP17 increases the starch content by up-regulating the genes involved in starch biosynthesis and increasing the activities of enzymes related to starch biosynthesis, especially amylopectin biosynthesis.  The role of the USP gene in starch biosynthesis is revealed for the first time in this study.  This gene is expected to be used to increase the starch yield and improve starch quality in sweetpotato.

Hybrid rice generally showed higher grain yield than inbred rice, but its overall performance is largely affected by lodging and lower grain quality.  Limited attention has been given to exploring genotypic variation and varietal traits for achieving high yield, superior quality, and strong lodging resistance simultaneously in both inbred and hybrid rice.  To address this gap, field experiments with five representative rice varieties from each rice type were conducted in Central China in 2020 and 2021.  The results showed that the average yield of hybrid rice in 2020 and 2021 was 8.01 and 8.63 t ha^–1, respectively, representing significant increases of 10.3 and 13.4% compared to inbred rice.  Importantly, hybrid rice showed comparable grain quality and lodging resistance to inbred rice.  Substantial genotypic variation was observed among the varieties for yield, grain quality, and lodging-related traits.  Efengsimiao (inbred) and Jinliangyou 534 (hybrid) showed the most balanced and superior agronomic performance within each variety type.  Key traits associated with the integration of high yield, superior quality, and strong lodging resistance included high spikelets per unit area, low grain length–width ratio, and short basal internode.  These findings highlighted the potential to select and breed rice varieties that optimize multiple desirable traits, offering a promising strategy to meet growing food demands in both quantity and quality.

Alternate wetting and drying (WD) irrigation is an effective water-saving practice for rice production but often increases nitrous oxide (N₂O) emissions.  Plant growth-promoting bacteria such as Bacillus subtilis (BS) can enhance crop growth; however, the combined effects of WD and BS on rice yield and N₂O emissions remain unclear.  A 3-year field experiment using two japonica rice cultivars was conducted to evaluate the effects of two irrigation regimes (continuous flooding (CF) and WD) and BS application (without BS, –BS; and with BS, +BS) on rice yield and N₂O emissions.  The results showed that BS application significantly increased the rice yields under both irrigation regimes.  Compared with CF–BS, CF+BS and WD+BS increased the yields by 3.9–9.0% and 5.8–12.6%, respectively, mainly due to a higher total spikelet number.  CF+BS had no significant effect on N₂O emissions, whereas WD–BS markedly increased cumulative N₂O emissions, while WD+BS reduced emissions by 34.8–45.9% compared with WD–BS.  The WD+BS treatment enhanced root oxidation activity and increased root surface area and volume density in the 20–40 cm soil layer.  It also reduced the soil NO₃⁻-N content, raised the NH₄⁺/NO₃⁻ ratio, and enhanced urease and sucrase activities, thereby promoting the accumulation of dissolved organic carbon (DOC) and microbial biomass nitrogen (MBN), along with a higher abundance of the nitrous oxide reductase gene (nosZ) associated with N₂O reduction.  Overall, integrating WD with BS increased rice yield while mitigating N₂O emissions.  The enhanced root function and aboveground agronomic traits, improved soil enzyme activity, and optimized nitrogen transformation and microbial processes were the key mechanisms for achieving a high yield with reduced environmental impacts.

Wheat (Triticum aestivum L.) is a major food crop grown worldwide.  However, field-grown wheat is generally restricted to only one generation per year and has a fluctuating yield, which limits wheat improvement and will fail to meet future food demands.  To minimize the generation time and increase total annual wheat production, five light regimens with varying day lengths and spectral distributions - 12 h light/12 h dark+white light (P12W), 17 h light/7 h dark+white light (P17W), 22 h light/2 h dark+white light (P22W), 22 h light/2 h dark+red:green:blue light at 6:3:2 (P22RGB), and 22 h light/2 h dark+red:blue light at 6:1 (P22RB) - were developed by adjusting the light-emitting diodes (LEDs) in a controlled environment.  The results showed that controlled wheat cultivation under LED lighting with varying day lengths and spectral distributions can potentially provide “faster” and “greater” grain production.  Prolonging the day length (from 12 to 17 h and then to 22 h) accelerated wheat development, particularly shortening the duration before flowering, and the longer the prolonged time, the earlier the flowering.  However, a 22 h day length (e.g., the P22W treatment) affected plant morphological traits, reduced dry matter accumulation, and resulted in a loss of yield-related components due to increased stress and disrupted pollen development.  Surprisingly, regulating the spectral distribution toward the red-light region under long-day conditions (e.g., the P22RB treatment) could partially restore the grain yield of wheat.  The light regime with a rich red-light region contributed to greater dry matter accumulation, carbohydrate flow to reproductive tissues, and sporopollenin biosynthesis, resulting in improved plant morphology and grain yield.  Collectively, the optimized light regimes represented by the P17W and P22RB treatments in controlled environment agriculture can produce 5–6 generations of wheat per year, yielding 3.16–5.87 kg m^–2 yr^–1, which is 3.59–6.68 times higher than field cultivation.  Thus, using appropriate LED light regimens is a favorable way to achieve rapid generation cycling and high productivity in controlled wheat cultivation.

Plastic film mulching (PFM) increases crop yields in semi-arid regions by reducing water losses and increasing soil temperatures, while crop production in these areas also serves as a significant source of ammonia (NH₃) emissions.  The effects of PFM on NH₃ emissions are mostly unknown because of interactions between greater N mineralization at higher temperatures and the film cover preventing NH₃ diffusion.  Therefore, our objectives were to (1) evaluate the effects of PFM on NH₃ emissions under field conditions, and (2) identify the maize yield and NH₃ emissions under climate change and atmospheric N deposition conditions using the DeNitrification-DeComposition (DNDC) model.  The experiment included four treatments: (1) no plastic film mulching without N fertilization (control), (2) plastic film mulching without N fertilization (PFM), (3) N fertilization without plastic film mulching (N), and (4) plastic film mulching with N fertilization (PFM+N).  The PFM increased maize yields by 211% and yield stability across the years when combined with N fertilization.  PFM reduced NH₃ emissions by 35% through three mechanisms: i) the high water content under PFM saturates soil pores, hindering NH₃ gas movement to the atmosphere; ii) the hot and wet conditions under PFM accelerate the nitrification rate, thus increasing pH buffering capacity during urea hydrolysis; and iii) the physical barrier created by PFM reduces NH₃ exchange between soil and air.  Daily NH₃ emissions increased with soil temperature, NH₄⁺ content, and pH, but declined with soil moisture under N fertilization.  The NH₃ emissions under PFM+N increased with NH₄⁺ content.  The parameterized DNDC model simulated the yield and daily NH₃ emissions very well.  PFM+N increased yield and reduced NH₃ emissions under the shared socioeconomic pathway (SSP) scenario and with N deposition.  Yield under PFM+N increased with increasing N deposition, whereas NH₃ emissions under PFM+N increased only under the high N deposition (N4) scenario compared with the no-deposition scenario, with no apparent increase under the N2 and N3 scenarios.  In conclusion, PFM increases yields and mitigates NH₃ emissions, and it can also potentially achieve similar benefits under future conditions.

Research on the yield-enhancing mechanisms of maize through ‘smart' plant morphology under dense planting conditions is a critical focus in modern agriculture.  However, the issue of yield stability in densely planted maize, particularly regarding lodging resistance, remains insufficiently examined in the literature.  A three-year field experiment was conducted using three hybrids (XD20, DH618 and DH605) and three plant density treatments (6.0×10⁴, 7.5×10⁴, and 9.0×10⁴ plants ha^–1) to investigate the effects of planting density on the lodging resistance and yield of summer maize hybrids with different plant morphologies.  According to the results, increasing the planting density significantly boosted the yield of DH605, while the yields of XD20 and DH618 exhibited initial increases followed by stabilization.  Compared to the low-density (L) treatment, the height parameters and center of gravity of summer maize under the high-density (H) treatment were significantly elevated.  This was accompanied by a pronounced reduction in light transmittance within the bottom and ear layers, a reduction in the mechanical strength of basal internodes, and an increased risk of lodging, particularly for the XD20 hybrid.  DH605 improved mechanical strength by enhancing the light distribution within the ear and bottom layers, and by optimizing basal internode characteristics.  Ultimately, the grain yield under the DH605-H treatment increased by 10.68 to 34.11% relative to XD20-H, with a concurrent reduction in lodging rates ranging from 72.66 to 92.29%.  Cellulose content within the basal internodes and the total area of vascular bundles in the outer layer were key factors, explaining 61.70% of mechanical strength variance.  Therefore, a high planting density significantly increased the yield but also lodging susceptibility.  Optimizing plant morphology improved the canopy light distribution, dry matter composition and anatomical structure of basal internodes, thereby enhancing lodging resistance and grain yield in densely planted maize.

Ensuring an adequate and nutritious food supply for the global population is a significant challenge in agricultural production practice.  Water and fertilizer are the main limiting factors in improving crop yield and quality.  However, it remains unclear whether the substitution of a portion of chemical nitrogen fertilizer with organic fertilizer, combined with reduced irrigation, can increase maize yield and quality through improvements in photo-physiological traits and nitrogen transportation.  A split-plot field experiment of maize was established in an arid area of northwestern China from 2021 to 2023.  Two irrigation levels formed the main plot: local conventional irrigation (I2, 4,050 m³ ha⁻¹) and reduced by 20% (I1, 3,240 m³ ha⁻¹).  Five equivalent nitrogen substitution ratios of chemical nitrogen with organic fertilizers formed a split plot, including sole chemical nitrogen fertilizer (F1), organic fertilizer substituting for 25% (F2), 50% (F3), 75% (F4), and 100% (F5) of chemical nitrogen fertilizer.  This study investigated the effects of combining organic and chemical nitrogen fertilizers under reduced irrigation on maize yield, quality, photo-physiological traits, and nitrogen transportation.  The results showed that reduced irrigation decreased maize yield and quality.  However, organic fertilizer substitution for 25% of chemical nitrogen increased maize yield and quality, with this effect greater than that observed with other equivalent nitrogen substitution ratios of chemical fertilizer with organic fertilizer.  A 20% reduction in irrigation combined with organic fertilizer substitution for 25% of chemical nitrogen (I1F2) increased maize grain yield and biomass by 13.0 and 8.9%, respectively, compared to local conventional irrigation and sole chemical nitrogen fertilizer (I2F1).  Meanwhile, I1F2 improved grain protein content by 10.0%, enhanced amino acid and vitamin B contents by 60.4 and 30.6%, and raised straw crude fat and crude protein contents by 23.1 and 5.6% compared to I2F1 in maize, respectively.  The reason for improving maize yield and quality with I1F2 was attributed to (1) improving leaf area index and leaf area duration at the blister (R2)−dough (R4) stage by 6.2 and 4.1%, increasing net photosynthetic rate by 43.8%, and enhancing pyruvate phosphate dikinase, phosphoenolpyruvate carboxykinase, and Rubisco activities by 9.8, 9.7, and 10.5%, respectively; (2) promoting nitrogen uptake and nitrogen accumulation after the R1 stage by 5.6 and 5.4% while maintaining nitrogen transportation quantity before the R1 stage.  Therefore, reducing irrigation by 20% combined with organic fertilizer substitution for 25% of chemical nitrogen can improve maize yield and quality via improving photo-physiological traits and nitrogen transportation in arid irrigation areas.

Echinacea purpurea is a perennial herbaceous horticultural plant belonging to the Asteraceae family.  It is easy to cultivate and well-known for its medicinal ingredients (e.g., chicoric acid) and high ornamental value.  However, studies on the synthesis and regulatory mechanisms of its secondary metabolites are limited.  Therefore, to advance research on E. purpurea, this study aimed to establish gene expression and silencing systems in E. purpurea.  First, a transient gene expression system mediated by Agrobacterium tumefaciens was developed in E. purpurea leaves.  After optimization, we found that injecting the fourth newly emerged leaf with the EHA105 strain and culturing for 4 d yielded the best expression results.  Then, a previously reported cut-dip-budding (CDB) system was adapted and improved to establish a gene expression system based on Agrobacterium rhizogenes.  By infecting the roots with A. rhizogenes, we detected efficient expression of the target gene after 30 d.  Using this system, we achieved expression of EpHTT, a key gene involved in chicoric acid synthesis, and significantly increased the accumulation of chicoric acid.  By expressing double-stranded RNA targeting EpHTT, we successfully silenced EpHTT expression and reduced chicoric acid accumulation.  We further investigated the protoplast-based transient gene expression system, studied key parameters such as enzyme concentration and osmotic pressure, and successfully achieved transient expression of the target gene in protoplasts.  Finally, a gene-silencing system in E. purpurea mediated by the tobacco rattle virus (TRV) was established, and EpCHLH was identified as the optimal silencing reporter gene, with the maximal silencing effect observed in 15-d-old seedlings.  By silencing genes involved in the chicoric acid biosynthesis pathway, such as EpHCT, EpHTT, and EpCAS, we successfully reduced chicoric acid accumulation.  In summary, this study successfully established various gene expression and silencing systems for E. purpurea, providing a valuable toolkit for further functional studies.

Vacuolar composition, particularly the type and abundance of metabolites and tonoplast proteins, critically determines fruit quality and flavor.  However, the specific vacuolar composition of fruits with different flavors at the fully ripe stage, especially regarding sugar accumulation, remains unclear.  In this study, we established an optimized protocol to overcome technical barriers in isolating intact vacuoles from fresh ripe citrus juice sacs of four citrus cultivars: NFMJ, Nanfeng tangerine (Citrus reticulata ‘97-2'); WZMG, Wenzhou satsuma (C. unshiu ‘Miyagawa'); NHER, ‘Newhall' navel orange (C. sinensis ‘Newhall'); MJY, Majiayou pomelo (C. grandis ‘Xipi Majia').  Subsequently, quasi-targeted metabolomics analysis and 4D-label-free proteomics analysis were conducted, identifying 640 metabolites and 1,782 proteins, respectively.  Notably, amino acids, flavonoids, lipids, carbohydrates, and organic acids collectively represented 70% of the total vacuolar metabolites.  Pummelo MJY vacuoles exhibited the highest sucrose accumulation, whereas tangerine NFMJ showed minimal sucrose content.  Proteomic profiling revealed vacuolar proteins participating in protein fate determination, metabolism, vesicle trafficking, solute transport, and energy supply.  Comparative analysis demonstrated significantly greater protein abundance variation between MJY and NFMJ than between other varieties.  In total, 158 transport proteins, including sugar-related transporters, were identified, and most of them were more abundant in MJY vacuoles.  The protein abundance of CsTST2 and CsERDL6 was greater in MJY vacuoles compared to other varieties, and the relative expression patterns of their encoding genes were consistent with sugar accumulation during fruit ripening.  Subcellular localization analysis confirmed their tonoplast localization.  Importantly, transgenic tomato fruits overexpressing these genes demonstrated both enhanced gene expression and increased sugar content.  This study systematically revealed cultivar-specific vacuolar composition and sugar accumulation strategies in ripe citrus fruits and provided key tonoplast proteins responsible for fruit quality improvement.