Salt-alkali stress has become one of the important factors restricting agricultural production in my country.Exploring the molecular mechanism of salt tolerance of crops has important theoretical and practical value for crop breeding.The purpose of this study is to clone the ZmMPI gene in corn and transform corn plants.First,qRT-PCR was used to analyze the ZmMPI expression changes in plants treated with saline-alkali solutions.Then DNAMAN software was used to perform multiple comparison analysis of the ZmMPI protein sequence.MEGA 7.0 software was used to construct a phylogenetic tree,and a series of software were used to analyze the ZmMPI protein sequence.ZmMPI performed bioinformatics analysis.Finally,molecular cloning technology was used to successfully clone the coding sequence of the ZmMPI gene,construct a plant overexpression vector,and use Agrobacterium-mediated genetic transformation method to transform the corn inbred line B104.The overexpression transgenic plants were transformed at the genome level,transcription level and protein level.Identify and analyze changes in expression levels.The results showed that the expression level of the ZmMPI gene showed an overall trend of first increasing and then decreasing after being subjected to salt-alkali stress;the ZmMPI protein sequence comparison result showed a similarity rate of 64.15%,and the phylogenetic tree showed that ZmMPI had the highest homology with Zea mays subsp.parviglumis ABA34115.1.The protein contained a protein domain Potato_inhibit,which had an α-helix,a random coil and a β-turn.It was relatively hydrophobic and had 10 predicted Potential phosphorylation sites;the identification results of the 49 transformation events obtained showed that the ZmMPI gene in 13 over-expressed transgenic lines could be expressed normally at the genome level,and the ZmMPI gene in 10 over-expressed transgenic lines could be transcribed and translated normally.Finally,10 overexpression transgenic lines capable of normal transcription and translation were obtained,laying the foundation for further exploring the molecular mechanism of ZmMPI gene in response to salt-alkali stress.

The transcription factor BnHY5-2 is associated with plant stress resistance.In order to reveal the response of Brassica napus L.transcription factor BnHY5-2 to salt alkali stress in B.napus,the response of BnHY5-2 to light and salt and alkali was analyzed by transient overexpression,qRT-PCR analysis and subcellular localization.The results revealed that under light conditions,the expression level of the BnHY5-2 gene in B.napus leaves and stems was 29.22 and 3.15 fold higher,respectively,compared to dark conditions.The higher sensitivity to light in leaves suggested that they were the primary site for light signal response.Under light conditions,the expression of BnHY5-2 in leaves and stems was significantly downregulated by 53.1% and 31.0%,respectively,when B.napus was planted in Dalian coastal saline-alkali soil;after applying saline-alkali treatment under dark conditions,the expression of BnHY5-2 was downregulated by 48.2% in the stem,while the difference in expression in the leaves was not significant,indicating organ differences,indicating that the leaves had stricter requirements for light conditions.In B.napus leaves with transient overexpression of BnHY5-2,two out of six genes related to saline-alkali stress(BnNAC32 and BnGS)showed upregulation by 1.25,3.28 fold,respectively,while the other four genes(Bnamy,BnAsp,BnNHX7,BnTPS)were downregulated by 24.8%,25.4%,71.0%,and 82.0%,respectively.Meanwhile,the content of the resistance substance betaine in B.napus increased from 0.256 to 0.573 mg/g,indicating an enhancement by 1.24 fold,suggesting that the overexpression of BnHY5-2 gene could improve the saline-alkali tolerance of B.napus.Subcellular localization results showed that the transcription factor BnHY5-2 was localized in the nucleus and regulates the expression of functional genes.Therefore,BnHY5-2 is not only related to light signaling but also participates in the saline-alkali resistance of Brassica napus L.

Calmodulin-like proteins(CMLs),one of the Ca²⁺ receptors in plants,are involved in the process of plant growth and development,as well as adaptation to environmental changes.To understand the sequence characteristics of garlic CMLs and their responses to osmotic stress,AsCML15 and AsCML42 genes from garlic variety Cangshan siliuban were cloned,and their expression patterns under drought and salt stress conditions were determined.The results showed that the open reading frame of AsCML15 and AsCML42 genes were 498 and 543 bp in length,respectively,encoding 165 and 180 amino acid residues.AsCML15 and AsCML42 harbored four and three EF-hand domains,respectively.AsCML42 was closer to Arabidopsis AtCML42 and AtCML43 in evolutionary relationship,whereas AsCML15 was more closely related to Arabidopsis AtCML15 and AtCML16.Real-time Quantitative PCR technology showed that AsCML15 and AsCML42 were expressed in bulbs,leaves,and roots,and these two genes can be induced by 200 mmol/L NaCl and 15% PEG6000.The AsCML15 and AsCML42 genes may be involved in the process of garlic resisting salt and drought stress,and their biological functions can be further identified.

Clarifying the effect of spring limited irrigation on the root development and grain yield of winter wheat in Haihe Plain is of great significance to reduce irrigation and improve water use efficiency.This study used Shimai 22 as the test material,irrigation treatments were traditional irrigation twice at jointing and anthesis stage(W2),no irrigation(W0),and single irrigation(W1)with four irrigation-time treatments(3L,4L,5L,and 6L)based on the number of leaves unfolded in spring.The results showed that compared with W2,W0 and W1 yield decreased by 54.6% and 24.4% respectively,the irrigation yield was highest at 4L in W1,and the effect of yield composition reduction was not significant.Limited irrigation reduced the total root weight density and root length density of winter wheat.During the anthesis period, the total root weight density of W1 decreased significantly by 17.2%, while the total root weight density and root length density of W0 decreased significantly by 47.5% and 35.1%, respectively. And under W1 condition, 4L has the highest total root weight density and root length density. The vertical distribution of roots showed that reducing the frequency of irrigation increased the distribution of roots in the soil layer below 40 cm,however,with the postponement of irrigation time,the root distribution of W1 deep soil decreased and root vigor increased.Among them, during the anthesis period, 4L was significantly higher than 6L by 28.8%, 14.2%, and 36.5% in the 120—160 cm, 160—200 cm, and 200—240 cm soil layers, respectively. Correlation and path analysis showed that total root weight density and root length density at joint—anthesis period had a positive effect on yield.The direct contribution of total root length density in 3L and 4L irrigation was the largest.Generally speaking,the root mass of 4L treatment was higher at jointing-anthesis period,the deep root distribution and root activity of 40—240 cm were increased,resulting in higher spike number and kernel number,which was beneficial to alleviate the decrease of winter wheat yield at limited irrigation,it can be used as an effective way of limited irrigation for winter wheat in Haihe Plain.

In order to screen out suitable water and nitrogen combinations for watermelons in Yellow River irrigation area of Ningxia, different water and nitrogen treatments were designed to study the effects of water and nitrogen interaction on SPAD value of watermelon leaves, fruit quality,yield and nitrogen uptake and utilization. The results showed that SPAD values were higher by W1N4,W2N3,W2N4,W3N3 and W3N4 treatment,the quality was better under nitrogenous fertilizer amounts at N2 and N3.The yield was the highest under W3N4 treatment,reaching 76 565.36 kg/ha and increased by 8.34% to 37.57% compared with other treatments significantly.Followed by W3N2 and W3N3 treatment.Compared with other levels,when the irrigation water level was W1,the water use efficiency of facility watermelon irrigation was higher.Among them,the irrigation water use efficiency of W1N3 and W1N4 treatment was higher,reaching 43.91,45.32 kg/ha respectively,while it was significantly increased by 14.00% to 56.40% from other treatments.Fruit nitrogen accumulation and total nitrogen accumulation under W3N4 treatment were all the highest compared with other treatments significantly,increasing by 22.75% to 192.36% and 17.00% to 123.39% respectively compared with the other treatments.Partial factor productivity of nitrogen and nitrogen fertilizer utilization rate under W3N2 treatment were all the highest compared with other treatments significantly.Partial factor productivity of nitrogen increased by 11.00% to 343.68%separately compared with the other treatments and nitrogen fertilizer utilization rate increased by 3.34 to 10.02 percentage points compared with other treatments.The correlation analysis showed that SPAD,the center of soluble solids,Vc,yield,irrigation water use efficiency and nitrogen accumulation,were all significantly positively correlated with each other,and they were significantly negatively correlated with partial factor productivity of nitrogen and nitrogen use efficiency,the edge of soluble solids was positively correlated with nitrogen accumulation of the plants,and negatively correlated with partial factor productivity of nitrogen and nitrogen use efficiency.To sum up,the watermelon had better quality when nitrogenous fertilizer amounts were N2(80 kg/ha) and N3(160 kg/ha),the yield-increasing effect was the best under the combination of water amount for W3(2 200 m³/ha)and nitrogenous fertilizer amount for N4(240 kg/ha).The interaction between high amount of irrigation water and nitrogenous fertilizer application is beneficial to the nitrogen absorption in watermelon,and the interaction between low nitrogen application amount and high nitrogenous fertilizer amount is conducive to utilization of nitrogen fertilizer.

In order to investigate the effect of reducing nitrogen and increasing density on the yield formation characteristics of ratooning rice,hybrid rice variety Chuangliangyou 669 was used as the material to conduct two years of field experiments under conditions of three nitrogen application rates(N1:180 kg/ha;N2:153 kg/ha;N3:126 kg/ha)and two plant row spacing(M1:20.0 cm×16.7 cm;M2:16.7 cm×16.7 cm).The results showed that:reducing nitrogen reduced the leaf area index(LAI)of ratooning rice,but increasing density within a reasonable range of nitrogen reduction could increase the LAI of the main and ratooning seasons.The LAI of N1M2 and N2M2 was higher in the interaction treatments.Reducing nitrogen and increasing density both reduced the SPAD value of ratooning rice leaves,but the effect of density was not significant.Reducing nitrogen led to a decrease in dry matter weight,while increasing density could significantly increase dry matter weight.The interaction treatment of N1M2 and N2M2 had a higher dry matter weight.Reducing nitrogen reduced the yield of ratooning rice,but increasing density within a reasonable range of nitrogen reduction could increase yield.The interaction treatment of N1M2 and N2M2 had a higher yield.Reducing nitrogen significantly reduced the number of effective panicles in the main season,the total number of grains per panicle,and the regeneration rate and number of effective panicles in the ratooning season.However,increasing density had a compensatory effect on the number of panicles.Reasonable nitrogen reduction and density increase(N2M2)could coordinate the relationship among yield components and achieve higher yields.The correlation analysis showed that reasonable nitrogen reduction and density increase increased the effective number of panicles and total grains per panicle in the main season,as well as the effective number of panicles in ratooning season mainly by increasing LAI and dry matter weight of the main and ratooning season,and thereby improving the yield of ratooning rice.Overall,the nitrogen reduction and density increase treatment N2M2(nitrogen rate of 153 kg/ha,plant row spacing of 16.7 cm×16.7 cm)can save 15% nitrogen and achieve a higher yield.

Soil organic carbon and humus components are affected by soil quality,fertilization management measures and other factors.In order to clarify the regulation effect of long-term chemical fertilizer application on soil organic carbon(SOC)and soil humus components in different soil layers,a 43 a(2021)long-term fertilization experiment was conducted in Laiyang,Shandong Province.Six treatments were selected:low nitrogen fertilizer(N1),high nitrogen fertilizer(N2),high nitrogen fertilizer combined with phosphorus fertilizer(NP),high nitrogen fertilizer combined with potassium fertilizer(NK),high nitrogen combined with phosphorus and potassium fertilizer(NPK)and no fertilizer control(CK).The results showed that compared with CK,N1 could significantly increase the SOC content of 0—5 cm,with an increase of 22.84%.Single nitrogen fertilizer treatment could significantly increase the SOC content of 5—10 cm,with an increase of 20.94% and 28.60% in N1 and N2,respectively.N1 could significantly increase the SOC content of 10—20 cm,with an increase of 17.05%,while other treatments had no significant change.Compared with CK,N1 could significantly increase the content of humic acid(HA)in 10—20 cm and 20—30 cm soil layers,with an increase of 22.86% and 40.49%,respectively,while there was no significant change in 0—10 cm soil layer.NP could significantly increase the content of fulvic acid(FA)in 0—5 cm and 5—10 cm soil layers by 89.44% and 124.63%,respectively.NK could significantly increase the content of FA in 10—20 cm soil layer by 100.22%,and NPK could significantly increase the content of FA in 20—30 cm soil layer by 107.48%.N1 could significantly increase the content of humin(Hu)in 0—5 cm soil layer,with an increase of 69.34%.N2 could significantly increase the content of Hu in 5—10 cm soil layer,with an increase of 66.18%.N1 could significantly increase the content of Hu in 10—20 cm soil layer,with an increase of 79.50%,while there was no significant change in 20—30 cm soil layer.In summary,under the conditions of this experiment,long-term application of chemical fertilizers can effectively improve the fixation of soil organic carbon in non-calcareous fluvo-aquic soil and change the composition of soil humus,and the effects of different fertilization strategies are quite different.Among them,the effect of single application of nitrogen fertilizer on carbon sequestration is better.

Abstract: Tetraploid wheat is the ancestor specie of common wheat and an important food crop.Aiming to provide new resistance sources for wheat variety breeding,the resistance tetraploid wheat germplasm was explored and their resistance genes were identified.TDI-1 is a cultivated emmer wheat that has been immune to powdery mildew in the field for many years.To determine the resistance genes carried by TDI-1,and provide a theoretical basis for genetic improvement of wheat resistance,a durum wheat TDU-1 that was susceptible to powdery mildew was used to hybridize with TDI-1,and their F₁ plants,F₂ population,and F_2:3 lines were obtained.Genetic analysis of resistance was conducted on parents TDI-1,TDU-1,and their hybrid offspring that were inoculated with powdery mildew isolate E09.Then,bulked segregant analysis method combined with molecular markers was used to map the resistance gene.The results showed that TDI-1 was susceptible to E09 during the seedling stage but immune during the adult stage.F₁ plants derived from the cross of TDI-1 and TDU-1 were immune to E09 during the adult stage.The resistance of adult F₂ individuals was separated,and the ratio of resistant and susceptible plants was 3:1($χ_{3:1}^{2}$=0.11,P=0.74);the ratio of the number of homozygous resistant,separated resistant,and homozygous susceptible F_2:3 lines was 1:2:1($χ_{1:2:1}^{2}$=0.47,P=0.79),indicating that the resistance to powdery mildew in the adult stage of TDI-1 was controlled by one dominant gene,temporarily named PmTDI-1.Subsequently,a set of molecular markers was used to amplify the parents and their F₂ population,and then four markers on chromosome 2A,including Xwmc407,NRM-2AS29,NRM-2AS45 and NRM-2AS84, confirmed to be linked to PmTDI-1. PmTDI-1 was between the flanking markers NRM-2AS45 and NRM-2AS84,with genetics distances of 1.8 cM and 4.6 cM,respectively.Therefore,the adult stage powdery mildew resistance gene PmTDI-1 was preliminarily localized on chromosome 2A.This study identified a novel dominant adult-plant-resistance powdery mildew gene PmTDI-1 from tetraploid wheat TDI-1.

To investigate the regulatory effect of DEAD-box helicase 21(DDX21)on the replication of Transmissible gastroenteritis virus(TGEV).Firstly,Western Blot was utilized to analyze the effect of TGEV infection on DDX21 expression.Furthermore,we constructed eukaryotic expression plasmids of porcine DDX21 and established knockdown stable cell lines.RT-qPCR,Western Blot,Indirect immunofluorescence(IFA)and TCID₅₀ assays were used to investigate the regulatory effect of DDX21 on TGEV replication in vitro.Western Blot analysis showed that the protein levels of DDX21 were significantly up-regulated in PK-15 cells at the early stage of TGEV infection.RT-qPCR,Western Blot,IFA and TCID₅₀ experiments showed that over-expression of DDX21 significantly increased the mRNA level and protein of TGEV N in a dose-dependent manner.And the amino acids 601—784 aa of DDX21 were critical for promoting TGEV replication.Otherwise,the titer of TGEV was significantly down-regulated in DDX21 knockdown cell lines,whereas the titer of TGEV in DDX21 knockdown cell lines was reversed under the rescue experiment.This study revealed for the first time that DDX21 promotes the proliferation of TGEV and identified the key domain of DDX21 in regulating TGEV replication,which provided a theoretical a basis for future research on the function of DDX21 protein and the pathogenesis of TGEV.

Glyphosate is currently the most widely used broad-spectrum herbicide.Cultivating glyphosate tolerant crops will help improve the effectiveness of chemical control on weed in farmlands,reduce the use of pesticide,and simplify preventive and control measures.To fully detect the glyphosate tolerance(GT)loci in wheat,484 germplasm resources from the Huang-huai wheat region were used to identify glyphosate toxicity.Based on the wheat 15K SNP array data,genome-wide association analysis(GWAS)was used to explore QTL related to glyphosate tolerance in wheat.The main results were as follows:the trend of changes in glyphosate tolerance of wheat varieties cultivated in different eras was slow,and the glyphosate tolerance had not significantly improved;three glyphosate tolerant wheat germplasms(including Henong 130,Jimai 782 and Taishan 23)were selected based on the phenotypic identification results of pesticide damage;seven QTL associated with the level of wheat pesticide damage were detected by GWAS,including 19 significant SNPs,distributed on wheat chromosomes 1A(0.00—30.48 Mb),1B(6.57—30.57 Mb),1D(0.00—22.98 Mb),4A(656.09—680.09 Mb),5A(508.19—532.19 Mb),6A(54.56—85.09 Mb),and 6D(12.02—36.02 Mb);the two QTL qGlyT-1A and qGlyT-6A located on wheat chromosomes 1A and 6A were the main effector sites for glyphosate tolerance in wheat,containing a total of 16 genes that may be related to glyphosate tolerance in wheat.

This study aimed to investigate the function of the anthocyanidin glycosyltransferase gene(UFGT)in the anthocyanin biosynthesis in common buckwheat.Guihong 1 was used as the experimental material.A UFGT gene,named FeUFGT1,was obtained by homologous alignment analysis,and cloned followed by performing on bioinformatics analysis.Overexpression vector of this gene was constructed,then transferred into Arabidopsis thaliana anthocyanin 3-O-glycosyltransferase mutant atugt78d2 to assess its function.The results revealed that the open reading frame of FeUFGT1 was 1 404 bp and encoded 467 amino acid residues with speculated molecular weight of 51.46 ku and theoretical isoelectric point of 4.97.FeUFGT1 protein contained GT-B type glycosyltransferase family domain and a PSPG-box,specific one of the plant UGT family at the C-terminus.The phylogenetic analysis showed that FeUFGT1 protein was closely related to the 3-O-glucosyltransferase of Siraitia grosvenorii UGT74AC1.The expression level of FeUFGT1 in the white-flower petals of Fengtian 1 was 3.7-fold as high as that in the red-flower petals of Guihong 1 with a significant difference.Mutant recovery experiment showed that FeUFGT1 could restore the phenotype of the Arabidopsis mutant which lacked anthocyanin accumulation.

The NAC(NAM,ATAF1/2,CUC2)gene is an important regulatory factor in the stress signal transduction network.Cloning the NAC gene in castor,studying its molecular characteristics and expression characteristics,aiming to provide data support for the potential function of the castor NAC gene.The RcNAC100-like gene of Tongbi No.5 was cloned by RT-PCR technology,and its molecular characteristics were analyzed,including bioinformatics,subcellular localization,expression patterns,and transcription activation domain analysis.The results showed that the full length of RcNAC100-like gene cDNA was 1 244 bp,including a 1 086 bp coding sequence(CDS),encoding 361 amino acids.The protein had more irregular coil and α-helix structures,and was a hydrophilic,non-secretory protein.Phylogenetic analysis showed that the RcNAC100-like protein was most closely related to NAC proteins in Manihot esculenta and Hevea brasiliensis,with highly similar motif composition and positioning.The subcellular localization of RcNAC100-like protein was consistent with the predicted results,located in the nucleus.The predicted cis-acting elements in the RcNAC100-like promoter region indicate the presence of multiple environmental response and growth-related elements.Expression pattern analysis showed that the RcNAC100-like gene had tissue-specific expression,with the highest relative expression level in the roots.Additionally,the gene could respond rapidly to adverse environments(drought,salt,cold,and ABA stress)and actively express,indicating that the RcNAC100-like gene might be a key gene in the castor's response to stress.Transcription activation assay results showed that the RcNAC100-like transcription factor has transcriptional activation activity in yeast.In summary,the RcNAC100-like gene may play an important role in the castor's resistance to adversity.