This study aimed to investigate the effects of substituting different proportions of chemical fertilizer with organic fer-tilizer on sweet corn yield and soil N2O emission characteristics,so as to provide a theoretical basis for establishing a nitrogen application regime that achieves both high crop yield and environmental friendliness in the oasis irrigation area of Northwest China.A two-year field positioning experiment was conducted at the Wuwei Oasis Agricultural Experimental Station.A conven-tional chemical fertilizer treatment(CK)was used as the control,and four organic fertilizer substitution treatments were set:re-placing 10%,20%,30%,and 40%of chemical fertilizer with organic fertilizer(M1,M2,M3,and M4,respectively).By dynami-cally monitoring soil N2O flux,soil ammonium nitrogen(NH4+-N)and nitrate nitrogen(NO3--N)contents,and the activities of nitrate reductase(NR)and nitrite reductase(NiR).we analyzed the effects of partial substitution of chemical fertilizer with or-ganic fertilizer on soil N2O emissions in sweet corn fields and the underlying mechanisms.Based on the mean results of the two-year experiment,compared with the CK treatment,the M2 treatment significantly increased sweet corn biomass yield and fresh ear yield by 12.57%and 4.51%,respectively,while the M3 and M4 treatments significantly reduced yields.All partial or-ganic fertilizer substitution treatments significantly reduced the peak N2O emissions after basal fertilization and the first topdres-sing,as well as the cumulative N2O emissions during the sweet corn growing season.Compared with CK,the M1,M2,M3,and M4 treatments reduced the global warming potential(GWP)of N2O by 2.52%-8.89%and the emission intensity(EI)by 3.26%-10.35%.Among them,the M3 treatment exhibited the lowest GWP,and the M2 treatment had the lowest EI.Mantel test and random forest model analysis revealed that cumulative soil N2O emissions were extremely significantly positively correlated with NH4+-N and NO3--N contents,as well as NR and NiR activities at the sowing stage,and significantly positively correlated with NO3--N content and NiR activity at the jointing stage.Further analysis using a structural equation model indicated that par-tial substitution of chemical fertilizer with organic fertilizer primarily reduced N2O emissions by decreasing the NH4+-N content at the sowing stage,thereby indirectly affecting NO3--N content and NiR activity.In conclusion,substituting 20%of chemical fer-tilizer with organic fertilizer(M2)ensures increased sweet corn yield while significantly reducing soil N2O emissions,and can be recommended as the optimal fertilization regime for balancing production efficiency and emission reduction goals in the oasis irrigation area.
The rapid development of high-throughput sequencing and phenotyping technologies has generated increasing large-scale genotype and phenotype datasets.The conventional genomic selection(GS)algorithm struggle to handle such data,and computational efficiency has become a key concern in genomic selection.In order to address this problem,this study pro-poses a novel computationally efficient Haseman-Elston regression+QR decomposition genomic selection(HQGS)method.First,Haseman-Elston regression is used to estimate genetic variance,followed by orthogonal triangular decomposition(QR decompo-sition)of the core population to obtain an approximate solution for high-dimensional matrices,which greatly improves computa-tional efficiency.In simulated data analysis,different levels of core population size,number of markers,true heritability,and training population size were set to evaluate HQGS,genomic best linear unbiased prediction(GBLUP),random forest(RF),and support vector machine(SVM).In terms of prediction accuracy,HQGS and GBLUP were similar in most cases,both significantly outperforming RF in all cases and outperforming SVM in most cases.In terms of computational efficiency,HQGS significantly outperformed GBLUP,RF,and SVM,with GBLUP being the least efficient.In real data analysis,for 14 traits in wheat population 1,HQGS showed significantly better prediction accuracy than GBLUP for 3 traits,was similar to GBLUP for 8 traits,signifi-cantly outperformed RF for 6 traits,was similar to RF for 5 traits,significantly outperformed SVM for 5 traits,and was similar to SVM for 5 traits.For yield data under four environments in wheat population 2,HQGS outperformed GBLUP in three environ-ments,outperformed RF in one environment,was similar to RF in two environments,outperformed SVM in two environments,and was similar to SVM in one environment.This study presents a novel computationally efficient genomic selection method that effectively avoids the inversion of large genetic relationship matrices,significantly improving computational efficiency while maintaining prediction accuracy,providing a more efficient and reliable new approach for handling large datasets.
Wheat is one of the most important food crops globally,providing humans with substantial dietary protein and calories.However,its production is confronted with multiple challenges,such as lodging,wheat stem sawfly infestation,and extreme weather stress,which severely restrict the achievement of high and stable yield.Wheat solid stem not only significantly improves stem strength and enhances lodging resistance,but also forms a physical barrier to resist wheat stem sawfly infection.Meanwhile,it exhibits stronger adaptive advantages under abiotic stresses such as drought and high temperature,making it a crucial trait re-source for wheat stress-resistant breeding.This review systematically summarizes the research progress in aspects of the determi-nation period and methods of wheat solid stem trait,the origin,creation and utilization of germplasm resources,the genetic ex-pression characteristics and regulatory networks,the mapping of major QTLs and functional genes,as well as the synergistic rela-tionship between this trait and yield-related traits and the mechanism of stress adaptation.Additionally,the controversies and defi-ciencies existing in current research are summarized,and the future research directions and application prospects are prospected,aiming to provide theoretical basis for genetic improvement of wheat solid stem trait.
Based on measurements and comparisons of growth traits,chlorophyll fluorescence parameters,and other related indi-ces in nine potato varieties under low-light treatment,the cultivar"Atlantic"was identified as low-light tolerant by principal component analysis.To investigate genes involved in the low-light response of"Atlantic",we performed transcriptome analysis after treatment with a light intensity of 10 μmol m-2 s-1 for 48 h.Using GO enrichment,KEGG pathway analysis,and transcrip-tion factor prediction,we identified the light-responsive transcription factor gene StPIF3 and cloned its full-length cDNA.StPIF3 was introduced into tobacco via agrobacterium-mediated transformation,and T1 transgenic lines were obtained by selfing.Bioin-formatics analysis,RT-qPCR,and chlorophyll fluorescence measurements were used to characterize and validate its function.StPIF3 encodes a 716-amino-acid protein with a predicted molecular weight of 76.77 kD and an isoelectric point of 7.26,and it is predicted to be hydrophilic and unstable.The StPIF3 protein contains a typical HLH domain and belongs to the bHLH family;phylogenetic analysis indicated that StPIF3 is most closely related to the tobacco homolog.Under 50 μmol m-2 s-1 light intensity,transgenic tobacco plants showed significantly higher Fv/Fm,qP,ETR,ETRmax,and SPAD values than wild-type plants,whereas F0 was lower.Overall,overexpression of StPIF3 markedly improves electron transport and light energy use efficiency,thereby enhancing photosynthetic performance and low-light tolerance.
The WUSCHEL-related homeobox(WOX)transcription factor family plays central roles in maintaining stem cell ho-meostasis and regulating organogenesis in plants.Genetic transformation of peanut(Arachis hypogaea L.),a globally important oilseed crop,remains severely limited by low regeneration efficiency.Here,we conducted a genome-wide identification and characterization of WOX genes in the peanut cultivar'Fuhuasheng'to pinpoint candidates potentially involved in organ regenera-tion and to provide a basis for overcoming regeneration-related constraints in peanut transformation.We identified 20 WOX genes and systematically analyzed their phylogenetic relationships,conserved domains,collinearity,and promoter features,and then profiled their expression across tissues and during adventitious shoot regeneration using transcriptome data.Phylogenetic analysis clustered the AhWOX genes into three clades(ancient,intermediate,and WUS).All AhWOX proteins contained a conserved ho-meodomain(HD),and several WUS-clade members also carried the WUS-box and EAR motifs.Collinearity analysis indicated that AhWOX7,AhWOX12,and AhWOX14 are orthologs of Arabidopsis thaliana WUS and WOX5 and of the soybean regenera-tion-related gene GmWOX18,respectively.However,these orthologs showed only low expression,whereas the ancient-clade genes AhWOX13 and AhWOX20 were consistently highly expressed across all stages of adventitious shoot regeneration.Promoter analysis revealed enrichment of cis-elements associated with meristem activity,and phylogenetic evidence suggested that Ah-WOX13 and AhWOX20 are orthologous to AtWOX14,a reported positive regulator of shoot regeneration.Collectively,our results highlight AhWOX13 and AhWOX20 as promising candidates for improving regeneration capacity in peanut,providing a frame-work to enhance peanut transformation and accelerate functional genomics and trait engineering in oilseed crops.
This study investigated how foliar selenium(Se)application affects chlorogenic acid,total phenols,flavonoids,and anthocyanins in light purple-fleshed potatoes,as well as the expression of genes involved in the anthocyanin biosynthesis pathway,with the aim of identifying the optimal external Se concentration and spray frequency to promote anthocyanin accu-mulation in tubers.The purple-skinned,light purple-fleshed cultivar'Diancaishu 104'was used as the experimental material.Sodium selenite was applied by foliar spraying at three Se concentrations:0(distilled water,CK),5(Se1),and 10 mg L-1(Se2),with two application frequencies(2 or 3 sprays).For the two-spray treatment,applications were performed at the tuber forma-tion and tuber bulking stages;for the three-spray treatment,applications were performed at the tuber formation,tuber bulking,and tuber maturation stages,giving a total of five treatments.Chlorogenic acid,total phenols,flavonoids,and anthocyanins were quantified,and the expression of anthocyanin pathway-related genes was analyzed.The results showed that two sprays of Se1 more effectively promoted anthocyanin synthesis in potatoes.Specifically,two foliar sprays of Se1 significantly upregu-lated StF3'5'H,StCHS,StDFR,StANS,and StMYB113 expression in the skin by 9.11-10.11-fold,and increased StCHS and StDFR expression in the flesh by 2.99-3.72-fold.In contrast,three sprays of Se2 were more effective at increasing chloro-genic acid and total phenols in tubers,raising their contents by 30.12%and 40.80%,respectively,compared with CK.Moreover,Se treatment strengthened the expression correlations among multiple structural genes and transcription factors in the anthocyanin biosynthesis pathway,facilitating the formation of a synergistic regulatory network and thereby promoting anthocyanin accumulation.
To elucidate the response mechanisms of rapeseed phenological stages to geographical environments and climate change in the Middle and Lower Reaches of the Yangtze River Plain,this study systematically analyzed the spatiotemporal pat-terns of key phenological stages and their durations using observational data from 50 meteorological stations spanning 1981 to 2024.Methods employed included kernel density estimation,linear trend analysis,and correlation analysis.The results revealed that:(1)Spatially,the relationship between rapeseed phenology and geographical factors exhibited a distinct stage-dependent shift.During the vegetative growth stage(sowing to five-leaf),phenological timing advanced with increasing latitude("high-latitude&early-sowing"),showing significant negative correlations with latitude(r=–0.200 to –0.285),primarily reflecting agronomic strategies to avoid winter frost.In contrast,during the reproductive growth stage(flowering to maturity),the pattern reversed to"high-latitude&late-flowering,"with strong positive correlations with latitude(r=0.665 to 0.731),suggesting that photoperiod and accumulated heat became dominant controlling factors.(2)Temporally,a coordinated pattern of"delayed early stages but advanced later stages"and"shortened initial phases but prolonged subsequent phases"was observed.From 1981 to 2024,over half of the sites(50%–58%)exhibited delays in vegetative stages,while reproductive stages tended to advance(64%–88%),with significantly earlier flowering observed at 88%of the stations.Phase duration shortened from sowing to flowering at 56%–68%of the sites,but lengthened after flowering—especially from green-ripening to maturity—at 78%of the sites,resulting in an overall shortened growth cycle at 64%of locations.(3)This phenological evolution is closely linked to the seasonal asymmetry of cli-mate change in the region,characterized by slower autumn warming and more rapid spring warming.These findings offer new insights into the geographical adaptation mechanisms of rapeseed phenology and provide valuable guidance for developing re-gion-specific adaptive strategies for rapeseed production under global climate change.
Transcriptomic studies investigating root responses to iron(Fe)deficiency have typically used entire underground root systems or mixed whole-root samples,which can dilute the strong transcriptional signals originating from root tips.To uncover the spatially resolved transcriptomic features of Fe deficiency responses in maize primary roots and elucidate the spatial division of labor in Fe uptake and homeostasis,we employed the maize inbred line B73.Seedlings at the three-leaf stage were grown un-der control(25 μmol L–1 Fe-EDTA)or Fe-deficient(0 μmol L–1 Fe-EDTA)conditions.RNA sequencing(RNA-seq)was per-formed on root tips(0–2 cm)and whole primary roots.An integrated analysis—including differentially expressed genes(DEGs),multi-level gene function enrichment,weighted gene co-expression network analysis(WGCNA),and qRT-PCR validation—was used to systematically compare the molecular mechanisms of Fe deficiency responses between root tips and whole roots.A total of 4206 DEGs(2450 upregulated)were identified in root tips,substantially more than the 325 DEGs(84 upregulated)found in whole roots,highlighting root tips as the key region for Fe sensing and response.Functional enrichment analysis revealed that root tips primarily activated metabolic pathways such as ribosome assembly and the TCA cycle,while whole roots were signifi-cantly enriched in processes including lignin biosynthesis and antioxidant defense.Several secondary metabolite biosynthesis pathways—including phenylpropanoid biosynthesis,various plant secondary metabolite biosynthesis,and flavonoid biosynthe-sis—were enriched in distinct root regions,suggesting diverse roles of secondary metabolites in Fe homeostasis.Genes involved in siderophore biosynthesis were specifically induced in root tips,supporting the synthesis of mugineic acids(MAs),the main phytosiderophores(PS)in grasses,and subsequent Fe chelation.Key transporter genes,such as natural resistance-associated macrophage protein 2(NRAMP2)and yellow stripe-like protein 12(YSL12),were predominantly expressed and upregulated in whole roots,facilitating Fe translocation within the plant.Additionally,several bHLH family transcription factors,known regula-tors of Fe homeostasis,were highly expressed in whole roots,indicating their potential role in coordinating Fe uptake and redis-tribution.This study delineates the spatially partitioned transcriptional landscape of Fe deficiency responses in primary roots,revealing a strategy in which root tips dominate PS biosynthesis,while whole roots coordinate Fe transport and systemic defense.The identification of spatially specific genes and pathways provides new insights into the molecular mechanisms underlying maize root adaptation to Fe deficiency stress.
This study integrates UAV-based hyperspectral imaging with ensemble learning to identify an optimal spectral estima-tion model for predicting leaf nitrogen content(LNC)in dryland forage maize,providing a methodological reference for impro-ving production efficiency and quality.The study was conducted on the Loess Plateau in central Gansu province,China,with forage maize as the target crop.Hyperspectral data were acquired using a V185G integrated gimbal hyperspectral imaging system mounted on a UAV.Spectral indices were generated from all possible two-band combinations using original reflectance spectra,first-derivative spectra,and continuum-removed spectra.Six machine-learning algorithms were evaluated,and Voting and Stac-king ensemble models were further developed to select the best-performing approach.Transformed spectra substantially strength-ened the relationships between spectral indices and LNC compared with the original bands.Among the six individual models,random forest regression(RFR),K-nearest neighbors(KNN),XGBoost,and gradient boosting decision tree(GBDT)achieved achieved relatively high accuracy across maize growth stages,with test-set R2 values of 0.7165-0.7713 and RMSE values of 2.4265-2.8296.These four models were then combined to build the ensemble models,both of which achieved test-set R2>0.7459 and RMSE<2.6358.The Voting ensemble based on first-derivative spectra delivered the best performance(R2=0.8152,RMSE=2.1253),indicating improved predictive accuracy and robustness through model integration.Overall,the Voting-first-derivative spectra(Voting-FDS)model enables rapid estimation of LNC at key growth stages,supporting in-season nutrient management and high-quality production in dryland forage maize.
Broomcorn millet is an ancient cereal crop that originated in China and plays a foundational role in the development of Chinese agricultural civilization.The AP2 subfamily has been shown to regulate plant growth,development,and responses to abiotic stresses;however,the number and its specific functions in broomcorn millet remain unclear.In this study,we performed a genome-wide identification of members of the AP2 subfamily in broomcorn millet using bioinformatics approaches based on its genome sequence.Analyses included gene structures and expression patterns under salt stress.A total of 20 PmAP2 subfamily members(PmAP2-1 to PmAP2-20)were identified at the genome-wide level,distributed across 15 chromosomes.Phylogenetic analys is clustered all PmAP2 encoded proteins into three subgroups:euANT,basalANT,and euAP2.Promoter cis-acting element analysis revealed that genes of the PmAP2 subfamily are involved in multiple biological processes,including plant hormone and abiotic stress,growth and development,and light responsive.Interspecies synteny analysis identified 3 and 27 syntenic gene pairs between broomcorn millet and Arabidopsis thaliana and Oryza sativa,respectively.Expression profiling indicated that PmAP2 genes exhibit both cultivar and tissue specificity,and the expression of all 20 members was induced by salt stress.PmAP2-1 and PmAP2-9,two salt stress-induced upregulated genes from broomcorn millet,were introduced into Arabidopsis thaliana via ge-netic transformation,and stably heritable transgenic lines were obtained.Root growth in transgenic Arabidopsis thaliana was affected by salt stress,with root length decreasing as the NaCl concentration increased.Under severe salt stress of 75 mmol L–1 and 100 mmol L–1 NaCl,the root lengths of transgenic plants showed significant differences compared with the wild type.These findings suggest that PmAP2-1 and PmAP2-9 may serve as potential target genes for the genetic improvement of salt tolerance in other staple crops.
Global warming has increased the frequency and severity of heat stress during the maize growing season in the Huang-Huai-Hai Plain of China,which can markedly hinder young ear development and cause substantial yield losses in summer maize.Methyl jasmonate(MeJA)is a biologically active compound that can alleviate abiotic stress and promote reproductive development,and thus represents a promising exogenous regulator for improving crop stress responses.This study aimed to clar-ify the effects of MeJA on young ear differentiation,fertilization,and seed-setting traits during the floret differentiation stage un-der heat stress.The summer maize cultivar Xianyu 335 was used as the experimental material.Exogenous MeJA was applied by foliar spraying at two key stages of ear differentiation(V9,9th leaf stage;V12,12th leaf stage)under simulated heat-stress condi-tions.By quantifying endogenous hormones and antioxidant responses,we elucidated how MeJA regulates ear morphology,floret number,and fertilization and seed-setting characteristics under heat stress.Exogenous MeJA significantly increased the contents of trans-zeatin+trans-zeatin riboside,salicylic acid,and jasmonic acid in young ears while reducing abscisic acid content.Compared with the control,MeJA also increased superoxide dismutase,peroxidase,and catalase activities in young ears and re-duced malondialdehyde accumulation,thereby enhancing stress tolerance and mitigating heat stress-induced damage.Accordingly,MeJA increased young ear length,diameter,and floret number by 5.54%-48.88%,12.34%-24.41%,and 2.51%-25.51%,respec-tively,and reduced the length of the undeveloped ear portion by 10.26%-50.00%.In addition,MeJA significantly increased the number of exposed silks and the floret fertilization rate while decreasing the grain abortion rate,resulting in marked increases in kernels per ear(48.36%-57.23%)and grain yield(49.14%-66.79%).Overall,MeJA alleviated heat stress-induced inhibition of ear differentiation by modulating endogenous hormone status and activating the antioxidant system in young ears,thereby reduc-ing oxidative damage and improving fertilization and seed-setting capacity.These findings provide a theoretical basis for devel-oping heat stress-resilient cultivation practices and stabilizing summer maize yield.
Peroxidase(POD)activity in wheat grains strongly influences processing quality and the color of wheat-based products,and is therefore an important target for quality improvement.In this study,151 wheat varieties(lines)from domestic and international sources were used to systematically characterize allelic variation at the Pod-A1,Pod-D1,and Pod-2D loci using molecular markers.Together with multi-year,multi-location measurements of grain POD activity,we evaluated the effects of individual alleles and their combinations on POD activity.Grain POD activity showed substantial genetic variation,with a mean of 674.39 U g-1 min-1,a range of 431.30-954.81 U g-1 min-1,and a coefficient of variation of 15.52%.Environ-ment,genotype,and their interaction all had highly significant effects on POD activity(P<0.01).All three loci significantly affected grain POD activity,and the favorable alleles were Pod-A1b,Pod-D1b,and Pod-2D-GG,respectively.In total,12 alle-lic combinations were identified and classified into high-,medium-,and low-activity combination types based on grain POD activity.POD activity differed significantly among the three types(P<0.05),whereas no significant differences were detected within each type.The genetic effects of the three loci on grain POD activity followed the order Pod-2D>Pod-A1>Pod-D1.Grain POD activity increased significantly with the number of favorable alleles(R2=0.9681,P<0.05);varieties(lines)pyramiding 2-3 favorable alleles had significantly higher POD activity than those carrying 0-1 favorable allele(P<0.05).Significant regional differences were observed in POD activity,allelic variation,and allelic-combination frequencies.Nine varieties,including Liangxing 66,Lankao 24,and Jimai 22,were identified as carrying all three favorable alleles and exhibi-ting POD activity above 800 U g-1 min-1.These findings provide a theoretical basis and germplasm resources for molecular marker-assisted breeding to optimize wheat grain POD activity.
U-box E3 ligases(PUBs)regulate plant self-incompatibility(SI),hormone signaling,and stress responses.By mining time-course transcriptome data from Brassica oleracea following self-pollination(0-60 min),we identified BoPUB3L,a PUB gene that is rapidly and specifically upregulated by self-pollination.The 2214 bp open reading frame encodes a 737-aa protein(81.27 kD;pI 6.04)containing a single U-box and five ARM repeats,lacking a signal peptide and transmembrane domain,and localizing to the nucleus.The BoPUB3L promoter contains multiple cis-acting elements related to light responsiveness,abscisic acid,auxin,and gibberellin responses,as well as meristem-associated expression.BoPUB3L is most highly expressed in the style,followed by sepals,petals,and buds,as confirmed by GUS staining.Transcript abundance increased continuously during the first 30 min after self-pollination and peaked at 15 min,reaching a level 15.65-fold higher than that after cross-pollination.Yeast two-hybrid,pull-down,and BiFC assays further showed that BoPUB3L interacts with the kinase domain of the S-locus receptor kinase(SRK).Together,these results identify BoPUB3L as a previously uncharacterized component of the SI response in B.oleracea and provide new insight into the molecular basis of self-incompatibility in crucifers.
This study aimed to clarify how different tillage practices and green manure incorporation during the winter fallow period affect soil physicochemical properties and peanut yield under continuous cropping,and to identify the optimal agronomic measure for alleviating obstacles associated with continuous spring peanut cropping.Field experiments were conducted from 2022 to 2024 at the agricultural experiment station of Shandong agricultural university.Under continuous peanut monocropping,three treatments were established:no tillage after peanut harvest(no-tillage,MG);plowing after harvest followed by ryegrass planting until the following year's heading stage and then incorporation as green manure(green manure returning,YQ);and plowing plus soil drying after harvest(plowing tillage,FG).Soil physical properties,nutrient status,enzyme activities,and peanut yield were monitored throughout all growth stages of the subsequent peanut season.Compared with MG,both YQ and FG sig-nificantly improved soil physical condition at the pod-filling stage,decreasing bulk density(BD)by 5.39%and 2.31%and in-creasing soil porosity(SP)by 9.62%and 5.84%,respectively.Both treatments also increased the proportion of macroaggregates(>5 mm,2-5 mm,and 1-2 mm)in the 0-30 cm soil layer.Moreover,YQ significantly increased total nitrogen(TN)and organic matter(OM)contents,as well as sucrase(SA)and urease(UA)activities,in both the 0-20 cm and 20-40 cm layers across all growth stages.Over two years,pod yield under YQ and FG increased by 18.85%and 9.22%,respectively,and kernel yield in-creased by 12.21%and 3.21%,respectively,relative to MG;these gains were mainly driven by an increase in pods per plant.Pod yield was positively correlated with TN,OM,UA,and SA,but negatively correlated with BD.Overall,both YQ and FG are effec-tive practices for mitigating continuous-cropping constraints in peanut by improving soil physicochemical properties,enhancing nutrient availability,and increasing hydrolytic enzyme activities,with YQ showing greater benefits than FG.
The development,dormancy and germination of seeds are critical processes in the plant life cycle,and are regulated by various genetic factors and environmental cues.Small RNAs(sRNAs)are a group of non-coding RNA molecules consisting of 19–24 nucleotides,and regulate the expression of genes encoding transcription factors and key regulatory proteins.They play important roles in morphogenesis,growth,development,and response on biotic and abiotic stresses in both plants and animals.Although some of the regulation mechanisms of plant sRNAs remain unclear,existed evidences indicate their significant regula-tory roles in seed development,dormancy,and germination.In the present paper,the research progresses of plant sRNAs in recent years were reviewed,mainly including sRNA biogenesis(biosynthesis)and action mechanism,as well as their regulatory roles in seed development,dormancy,and germination.Additionally,we have highlighted key scientific issues requiring further investiga-tion in this field.The aim is to deepen our understanding of sRNA-mediated molecular mechanisms in these processes,thereby providing insights into improving seed quality,yield,and germination vigor.
Rapeseed(Brassica napus L.)is China's leading oilseed crop,and high yield depends heavily on nitrogen(N)fertilizer inputs;however,nitrogen use efficiency remains relatively low.Rapeseed biomass is primarily derived from photosynthesis.En-hancing the net photosynthetic rate(Pn)and photosynthetic nitrogen use efficiency(PNUE)may provide a feasible approach to simultaneously improve yield and nitrogen use efficiency,thereby reducing N fertilizer application,increasing rapeseed produc-tion,and supporting sustainable development of the rapeseed industry. Here,we conducted a hydroponic experiment with differ-ent N levels using two rapeseed germplasms that differed significantly in leaf area and Pn. During leaf development,we quantified dynamic changes in leaf N content,photosynthetic capacity,functional N fractions,and ribulose-1,5-bisphosphate carboxy-lase/oxygenase (Rubisco) characteristics to elucidate how N allocation regulates Pn and PNUE. Leaf N content declined with growth,but Pn did not decrease consistently,and Pn increased with higher N supply. Photosynthetic N (Npsn) and storage N (Nstore) were the dominant components of leaf N,accounting for 83.12％-97.61％. During leaf expansion,Npsn changed little whereas Nstore declined markedly,which helped maintain Pn at lower total leaf N and improved PNUE. When leaf N content fell below 1.77 g m-2,both Npsn and Nstore decreased linearly,leading to significant reductions in Pn and PNUE. During leaf senescence,the decline in Npsn was 6.24％-19.07％ greater than that of Nstore,resulting in pronounced decreases in both Pn and PNUE. Rubisco content was significantly and positively correlated with Npsn. The germplasm Yunyou 9,which had higher Pn,showed higher Npsn and Rubisco content than Fuyou 3,which had larger leaf area,with increases of 5.63％-40.37％ and 0.38％-38.02％,respectively. Both Npsn and Nstore increased with increasing N supply,and Pn increased with Npsn. Overall,during leaf development,Rubisco helped maintain Npsn while Nstore declined,supporting higher Pn and improved PNUE. Therefore,optimizing within-leaf N alloca-tion by precisely regulating Rubisco content may be an effective strategy to further enhance rapeseed photosynthetic capacity and nitrogen use efficiency.
To comprehensively elucidate the transcription factor regulatory network underlying salt-stress responses in rice seed-ling roots,we used the rice male sterile line Huaxing 166S as material,treated seedling roots with three NaCl concentrations(0,0.25%,and 0.50%)for one week and recorded phenotypic data.RNA-seq was then used to characterize gene expression patterns,detecting 30,378 genes,of which 26,315 were identified as significantly differentially expressed genes(DEGs).Pathway enrich-ment analysis showed that,across all three NaCl treatments,DEGs were significantly enriched in secondary metabolism-related pathways.Based on the DEG dataset,we further identified 326 differentially expressed transcription factors and constructed a core interaction network comprising 88 transcription factors.Functional enrichment analysis indicated that this core network was mainly involved in plant hormone signal transduction,the plant MAPK signaling pathway,and the plant circadian rhythm path-way.In addition,quantitative real-time PCR(qPCR)validation showed that,following salt stress,10 WRKY family genes were specifically highly expressed in rice roots.Together,these transcriptome data across three NaCl concentrations define the gene expression landscape and a core transcription factor interaction network in rice seedling roots,providing a basis for dissecting the molecular regulatory mechanisms of rice root responses to salt stress.
As China's High-Standard Farmland Construction Program advances,many dryland wheat fields can now receive a one-off irrigation during the growing season(hereafter,one-off irrigation).To evaluate the effects of tillage practices and nitrogen(N)rates on wheat yield and quality under one-off irrigation,we conducted a two-factor split-plot experiment from 2020 to 2022 at three sites in Luoyang,Henan province(Xiaolangdi town,Mengjin county;Yaling town,Yichuan county;and Xiaojie town,Luoning county).Tillage practice was the main-plot factor—rotary tillage(RT),subsoiling(SS),and plough tillage(PT)—and N rate was the subplot factor at 0(N0),120(N120),180(N180),and 240(N240)kg hm-2.We measured grain yield,protein content and protein fractions,grain Zn content,and key processing-quality traits.Tillage practice and N rate significantly affected wheat yield and quality;their interaction significantly influenced grain yield,protein yield,and the contents of all protein components except albumin.Compared with PT and RT,SS increased grain yield by 6.9%and 12.6%,respectively,and increased protein yield by 7.7%and 14.5%,while generally improving protein content,most protein fractions,processing quality,and grain Zn content(with a few site-year exceptions).Relative to PT,SS increased albumin,globulin,gliadin,and glutenin contents as well as dough development time,stability time,wet gluten content,sedimentation value,extensibility,maximum resistance,and grain Zn content by 21.9%,19.0%,12.5%,8.0%,18.6%,28.4%,8.2%,26.4%,10.1%,14.0%,and 12.6%,respectively;compared with RT,the corresponding increases were 22.0%,19.6%,19.7%,15.0%,19.5%,32.8%,9.1%,27.8%,10.3%,22.6%,and 23.2%,respectively.Across all tillage practices,increasing N rate led to an initial increase followed by a plateau in yield,protein yield,protein frac-tions,processing-quality traits,and grain Zn content.In most cases,N180 and N240 did not differ significantly,and both outper-formed N120.Except for grain yield at the Xiaolangdi site and gliadin content in 2021-2022,SSN180 achieved similar yield,quality,economic returns,and input-output ratio to SSN240,while outperforming the other treatments in most comparisons.Overall,subsoiling combined with 180 kg hm-2 N is recommended for dryland regions where one-off irrigation is available,as it can simultaneously improve wheat yield,quality,and economic benefits.
Lateral organ boundaries domain(LBD)family genes play important roles in a wide range of plant biological processes.Previous studies have shown that class Ⅰ LBD genes are involved in the regulation of flowering time;however,whether class Ⅰ LBD genes have similar functions in upland cotton remains unclear.In this study,we identified and characterized class Ⅰ LBD family members at the whole-genome level in upland cotton and screened flowering-related candidate genes through haplotype analysis.The expression patterns of candidate genes in different tissues and in early-and late-flowering varieties were examined using RNA-seq and RT-qPCR,respectively.The function of the target gene was validated by virus-induced gene silencing(VIGS),followed by analysis of its breeding-related evolutionary dynamics and the development of molecular markers.In total,102 class Ⅰ GhLBD genes were identified;they were unevenly distributed across 26 chromosomes and were classified into six groups based on evolutionary relationships.LBD members within the same group showed similar motif composition and arrangement.Inte-grating haplotype and expression analyses,GhLBD6 was identified as a candidate gene associated with flowering time.VIGS combined with paraffin sectioning and RT-qPCR showed that suppression of GhLBD6 accelerated floral bud differentiation and significantly advanced budding and flowering by 6.57 d and 6.86 d,respectively.Two haplotypes(GhLBD6-Hap 1 and GhLBD6-Hap 2)were identified in the GhLBD6 coding region;among them,GhLBD6-Hap 1 represents a favorable early-flowering allele and appears to have been under artificial selection during upland cotton breeding.Finally,we developed a kompetitive allele-specific PCR(KASP)molecular marker to distinguish the two GhLBD6 haplotypes.Together,these forward-and reverse-genetic results demonstrate that GhLBD6 contributes to flowering-time regulation in upland cotton,providing a basis for molecular breeding of early-maturing cotton.
Fusarium ear rot(FER),caused by Fusarium verticillioides,is one of the most destructive fungal diseases limiting maize(Zea mays L.)production.The mitogen-activated protein kinase(MAPK)cascade is a central regulator of plant growth,development,and stress responses.Previous studies have shown that ZmMAPKs can enhance resistance to fungal pathogens by upregulating defense-related genes and activating key enzymes;however,the roles of individual MAPK family members in path-ways associated with FER resistance remain unclear.Here,we conducted a comprehensive analysis of the ZmMAPK gene family,including genome-wide identification and characterization,chromosomal localization,phylogenetic reconstruction,collinearity analysis,promoter cis-element prediction,tissue-specific expression profiling,and expression responses to F.verticillioides infec-tion.In total,24 MAPK genes were identified in the maize B73 reference genome(V5).Phylogenetic analysis grouped these genes into four subgroups,with highly conserved exon-intron structures within each subgroup.Groups A,B,and C contain the canonical Thr-Glu-Tyr(TEY)activation motif,whereas group D contains the Thr-Asp-Tyr(TDY)motif.Expression analyses showed pronounced tissue-specific differences,suggesting functional diversification within the family.RT-qPCR further indicated that,after F.verticillioides inoculation,ZmMAPK12,ZmMAPK22,ZmMAPK23,and ZmMAPK24 were differentially expressed between the resistant inbred line Qi 319 and the susceptible inbred line B73.Sequence comparisons revealed that,in addition to SNPs,structural variants such as transposon insertions occurred in both promoter and coding regions of these genes.Together,these results suggest that these MAPKs may participate in regulatory pathways controlling maize responses to F.verticillioides infection.This study provides a foundation for elucidating how MAPK cascades contribute to FER resistance and offers candidate genes to support genetic improvement of disease-resistant maize varieties.
