Host-induced gene silencing of the Verticillium dahliae thiamine transporter protein gene(VdThit)confers resistance to Verticillium wilt in cotton

Verticillium wilt(VW),induced by the soil-borne fungus Verticillium dahliae(Vd),poses a substantial threat to a diverse array of plant species.Employing molecular breeding technology for the development of cotton varieties with heightened resistance to VW stands out as one of the most efficacious protective measures.In this study,we successfully generated two stable transgenic lines of cotton(Gossypium hirsutum L.),VdThitRNAi-1 and VdThit-RNAi-2,using host-induced gene silencing(HIGS)technology to introduce double-stranded RNA(dsRNA)targeting the thiamine transporter protein gene(VdThit).Southern blot analysis confirmed the presence of a single-copy insertion in each line.Microscopic examination showed marked reductions in the colonization and spread of Vd-mCherry in the roots of VdThit-RNAi cotton compared to wild type(WT).The corresponding disease index and fungal biomass of VdThit-RNAi-1/2 also exhibited significant reductions.Real-time quantitative PCR(qRT-PCR)analysis demonstrated a substantial inhibition of VdThit expression following prolonged inoculation of VdThit-RNAi cotton.Small RNA sequencing(sRNA-Seq)analysis revealed the generation of a substantial number of VdThit-specific siRNAs in the VdThit-RNAi transgenic lines.Additionally,the silencing of VdThit by the siVdThit produced by VdThit-RNAi-1/2 resulted in the elevated expression of multiple genes involved in the thiamine biosynthesis pathway in Vd.Under field conditions,VdThit-RNAi transgenic cotton exhibited significantly enhanced disease resistance and yield compared with WT.In summary,our findings underscore the efficacy of HIGS targeting VdThit in restraining the infection and spread of Vd in cotton,thereby potentially enabling the development of cotton breeding as a promising strategy for managing VW.

Identification of the lysine and histidine transporter family in Camellia sinensis and the characterizations in nitrogen utilization

In plants,the lysine and histidine transporter(LHT)family represent a class of proteins that mediate the uptake,translocation,and utilization of amino acids.The tea plant(Camellia sinensis)is a perennial evergreen with a relatively high level of amino acids.However,systematic identification and molecular characterization of the LHT gene family has rarely been reported in tea plants.In this study,22 CsLHTs were identified from the‘Shuchazao’genome and classified into two groups.The modeled three-dimensional structure and the conserved domains presented a high similarity among the LHTs proteins.Moreover,it was predicted that a few genes were conserved through the analysis of the physiochemical characters,structures and cis-elements in promoters.The expression patterns in tea plants revealed that CsLHT7 was mainly expressed in the roots,and CsLHT4 and CsLHT11 exhibited relatively high expression in both the roots and leaves.Moreover,the expression of all three genes could be induced by organic nitrogen.Additionally,heterogeneous expression of CsLHT4,CsLHT7 and CsLHT11 in Arabidopsis thaliana decreased the aerial parts biomass compared with that in WT plants while significantly increased the rosette biomass only for CsLHT11transgenic plants versus WT plants.Overall,our results provide fundamental information about CsLHTs and potential genes in N utilization for further analysis in tea plants.

Global characterization of OsPIP aquaporins reveals that the H_(2)O_(2)transporter OsPIP2;6 increases resistance to rice blast

Plasma membrane intrinsic proteins(PIPs)are conserved plant aquaporins that transport small molecules across the plasma membrane to trigger instant stress responses and maintain cellular homeostasis under biotic and abiotic stress.To elucidate their roles in plant immunity to pathogen attack,we characterized the expression patterns,subcellular localizations,and H_(2)O_(2)-transport ability of 11 OsPIPs in rice(Oryza sativa),and identified OsPIP2;6 as necessary for rice disease resistance.OsPIP2;6 resides on the plasma membrane and facilitates cytoplasmic import of the immune signaling molecule H_(2)O_(2).Knockout of OsPIP2;6 increases rice susceptibility to Magnaporthe oryzae,indicating a positive function in plant immunity.OsPIP2;6 interacts with OsPIP2;2,which has been reported to increase rice resistance to pathogens via H_(2)O_(2)transport.Our findings suggest that OsPIP2;6 cooperates with OsPIP2;2 as a defense signal transporter complex during plant–pathogen interaction.

Sodium-dependent glucose transporter 2 inhibitors effects on myocardial function in patients with type 2 diabetes and asymptomatic heart failure

BACKGROUND Sodium-dependent glucose transporter 2 inhibitors(SGLT2i)have shown efficacy in reducing heart failure(HF)burden in a very heterogeneous groups of patients,raising doubts about some contemporary assumptions of their mechanism of action.We previously published a prospective observational study that evaluated mechanisms of action of SGLT2i in patients with type 2 diabetes who were in HF stages A and B on dual hypoglycemic therapy.Two groups of patients were included in the study:the ones receiving SGLT2i as an add-on agent to metformin and the others on dipeptidyl peptidase-4 inhibitors as an add-on to metformin due to suboptimal glycemic control.AIM To evaluate the outcomes regarding natriuretic peptide,oxidative stress,inflammation,blood pressure,heart rate,cardiac function,and body weight.METHODS The study outcomes were examined by dividing each treatment arm into two subgroups according to baseline parameters of global longitudinal strain(GLS),N-terminal pro-brain natriuretic peptide,myeloperoxidase(MPO),high-sensitivity C-reactive protein(hsCRP),and systolic and diastolic blood pressure.To evaluate the possible predictors of observed changes in the SGLT2i arm during follow-up,a rise in stroke volume index,body mass index(BMI)decrease,and lack of heart rate increase,linear regression analysis was performed.RESULTS There was a greater reduction of MPO,hsCRP,GLS,and blood pressure in the groups with higher baseline values of mentioned parameters irrespective of the therapeutic arm after 6 months of follow-up.Significant independent predictors of heart rate decrease were a reduction in early mitral inflow velocity to early diastolic mitral annular velocity at the interventricular septal annulus ratio and BMI,while the predictor of stroke volume index increase was SGLT2i therapy itself.CONCLUSION SGLT2i affect body composition,reduce cardiac load,improve diastolic/systolic function,and attenuate the sympathetic response.Glycemic control contributes to the improvement of heart function,blood pressure control,oxidative stress,and reduction in inflammation.

Increased excitatory amino acid transporter 2 levels in basolateral amygdala astrocytes mediate chronic stress–induced anxiety-like behavior

The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.

OsNPF3.1,a nitrate,abscisic acid and gibberellin transporter gene,is essential for rice tillering and nitrogen utilization efficiency

Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone transport and rice growth and development remains unknown.In this study,we described OsNPF3.1 as an essential nitrate and phytohormone transporter gene for rice tillering and nitrogen utilization efficiency(NUtE).OsNPF3.1 possesses four major haplotypes of its promoter sequence in 517 cultivars,and its expression is positively associated with tiller number.Its expression was higher in the basal part,culm,and leaf blade than in other parts of the plant,and was strongly induced by nitrate,abscisic acid(ABA)and gibberellin 3(GA_3)in the root and shoot of rice.Electrophysiological experiments demonstrated that OsNPF3.1 is a pH-dependent low-affinity nitrate transporter,with rice protoplast uptake assays showing it to be an ABA and GA_3 transporter.OsNPF3.1 overexpression significantly promoted ABA accumulation in the roots and GA accumulation in the basal part of the plant which inhibited axillary bud outgrowth and rice tillering,especially at high nitrate concentrations.The NUtE of OsNPF3.1-overexpressing plants was enhanced under low and medium nitrate concentrations,whereas the NUtE of OsNPF3.1 clustered regularly interspaced short palindromic repeats(CRISPR)plants was increased under high nitrate concentrations.The results indicate that OsNPF3.1 transports nitrate and phytohormones in different rice tissues under different nitrate concentrations.The altered OsNPF3.1 expression improves NUtE in the OsNPF3.1-overexpressing and CRISPR lines at low and high nitrate concentrations,respectively.

A mutation in the promoter of the yellow stripe-like transporter gene in cucumber results in a yellow cotyledon phenotype

Leaf color mutants in higher plants are considered to be ideal materials for studying the chlorophyll biosynthesis,photosynthesis mechanism and chloroplast development.Herein,we identified a spontaneous mutant,yc412,in cultivated cucumber that exhibited yellow cotyledons.The yellow-lethal mutant was diagnosed with an abnormal chloroplast ultrastructure,and reduced photosynthetic capacity and pigment content.Through bulked segregant analysis-based whole-genome sequencing and fine genetic mapping,we narrowed the yellow cotyledons (yc) locus to a 96.8 kb interval on chromosome 3.By resequencing and molecular cloning,we showed that Csyc is a potential candidate gene,which encodes a yellow stripe-like (YSL) transporter.The T to C mutation in the promoter region of Csyc caused the yellow cotyledon phenotype in yc412.Compared to YZU027A (WT),the expression of Csyc was significantly downregulated in the cotyledons of yc412.Silencing of Csyc in cucumber via virus-induced gene silencing resulted in chlorotic leaves,mainly by suppressing the chlorophyll content.Furthermore,a comparative transcriptome analysis revealed that chloroplast-related genes and chlorophyll biosynthesis genes were significantly downregulated in yc412 cotyledons.Our results provide new insights into the molecular function of the YSL transporter in plant chloroplast development and chlorophyll synthesis.

Effects of the kinetic pattern of dietary glucose release on nitrogen utilization, the portal amino acid profile, and nutrient transporter expression in intestinal enterocytes in piglets

Background Promoting the synchronization of glucose and amino acid release in the digestive tract of pigs could effectively improve dietary nitrogen utilization.The rational allocation of dietary starch sources and the exploration of appropriate dietary glucose release kinetics may promote the dynamic balance of dietary glucose and amino acid supplies.However,research on the effects of diets with different glucose release kinetic profiles on amino acid absorption and portal amino acid appearance in piglets is limited.This study aimed to investigate the effects of the kinetic pattern of dietary glucose release on nitrogen utilization,the portal amino acid profile,and nutrient transporter expression in intestinal enterocytes in piglets.Methods Sixty-four barrows(15.00±1.12 kg)were randomly allotted to 4 groups and fed diets formulated with starch from corn,corn/barley,corn/sorghum,or corn/cassava combinations(diets were coded A,B,C,or D respectively).Protein retention,the concentrations of portal amino acid and glucose,and the relative expression of amino acid and glucose transporter m RNAs were investigated.In vitro digestion was used to compare the dietary glucose release profiles.Results Four piglet diets with different glucose release kinetics were constructed by adjusting starch sources.The in vivo appearance dynamics of portal glucose were consistent with those of in vitro dietary glucose release kinetics.Total nitrogen excretion was reduced in the piglets in group B,while apparent nitrogen digestibility and nitrogen retention increased(P<0.05).Regardless of the time(2 h or 4 h after morning feeding),the portal total free amino acids content and contents of some individual amino acids(Thr,Glu,Gly,Ala,and Ile)of the piglets in group B were significantly higher than those in groups A,C,and D(P<0.05).Cluster analysis showed that different glucose release kinetic patterns resulted in different portal amino acid patterns in piglets,which decreased gradually with the extension of feeding time.The portal His/Phe,Pro/Glu,Leu/Val,Lys/Met,Tyr/Ile and Ala/Gly appeared higher similarity among the diet treatments.In the anterior jejunum,the glucose transporter SGLT1 was significantly positively correlated with the amino acid transporters B0AT1,EAAC1,and CAT1.Conclusions Rational allocation of starch resources could regulate dietary glucose release kinetics.In the present study,group B(corn/barley)diet exhibited a better glucose release kinetic pattern than the other groups,which could affect the portal amino acid contents and patterns by regulating the expression of amino acid transporters in the small intestine,thereby promoting nitrogen deposition in the body,and improving the utilization efficiency of dietary nitrogen.

Glutamine transporters as effective targets in digestive system malignant tumor treatment

Glutamine is one of the most abundant non-essential amino acids in human plasma and plays a crucial role in many biological processes of the human body.Tumor cells take up a large amount of glutamine to meet their rapid proliferation requirements,which is supported by the upregulation of glutamine transporters.Targeted inhibition of glutamine transporters effectively inhibits cell growth and proliferation in tumors.Among all cancers,digestive system malignant tumors(DSMTs)have the highest incidence and mortality rates,and the current therapeutic strategies for DSMTs are mainly surgical resection and chemotherapy.Due to the relatively low survival rate and severe side effects associated with DSMTs treatment,new treatment strategies are urgently required.This article summarizes the glutamine transporters involved in DSMTs and describes their role in DSMTs.Additionally,glutamine transportertarget drugs are discussed,providing theoretical guidance for the further development of drugs DSMTs treatment.

Genome-Wide Discovery and Expression Profiling of the SWEET Sugar Transporter Gene Family in Woodland Strawberry (Fragaria vesca) under Developmental and Stress Conditions: Structural and Evolutionary Analysis

The SWEET(sugar will eventually be exported transporter)family proteins are a recently identified class of sugar transporters that are essential for various physiological processes.Although the functions of the SWEET proteins have been identified in a number of species,to date,there have been no reports of the functions of the SWEET genes in woodland strawberries(Fragaria vesca).In this study,we identified 15 genes that were highly homolo-gous to the A.thaliana AtSWEET genes and designated them as FvSWEET1–FvSWEET15.We then conducted a structural and evolutionary analysis of these 15 FvSWEET genes.The phylogenetic analysis enabled us to categor-ize the predicted 15 SWEET proteins into four distinct groups.We observed slight variations in the exon‒intron structures of these genes,while the motifs and domain structures remained highly conserved.Additionally,the developmental and biological stress expression profiles of the 15 FvSWEET genes were extracted and analyzed.Finally,WGCNA coexpression network analysis was run to search for possible interacting genes of FvSWEET genes.The results showed that the FvSWEET10 genes interacted with 20 other genes,playing roles in response to bacterial and fungal infections.The outcomes of this study provide insights into the further study of FvSWEET genes and may also aid in the functional characterization of the FvSWEET genes in woodland strawberries.

Crosslink among cyclin-dependent kinase 9,ATP binding cassette transporter G2 and Beclin 1 in colorectal cancer

Colorectal cancer(CRC)ranks third in the number of cancers mainly because of the inability to diagnose it at an early stage.The pathogenesis of CRC is complicated,which is the result of the complex interaction of multiple genetic and environmental factors.Currently,one of the main treatments for CRC is chemotherapy.But the primary cause of CRC treatment failure is drug resistance.The expression of cyclin-dependent kinase 9(CDK9)was correlated with elevated autophagy levels in colon cancer,and high expression of CDK9 indicates a poor prognosis in CRC.The incidence of autophagy and the expressions of Beclin 1 and ATP binding cassette transporter G2 are different in left and right colon cancer,and autophagy may be involved in the occurrence of chemotherapy resistance.In this article,the roles of CDK9,ATP binding cassette transporter G2 and Beclin 1 in CRC were elucidated,emphasizing the linkages among them and providing potential therapeutic targets of CRC.

Effects of sodium-dependent glucose transporter 2 inhibitors in patients with type 2 diabetes mellitus and asymptomatic heart failure

Sodium-dependent glucose transporter 2 inhibitors(SGLT2i)have been increa-singly used with proven efficacy in patients with heart failure(HF),regardless of diabetes status.GrubićRotkvićet al recently published an observational study on SGLT2i therapy in patients with type 2 diabetes mellitus and asymptomatic HF.They found that the use of SGLT2i led to reduced cardiac load and improved cardiovascular performance,reinforcing the evolving paradigm that SGLT2i are not merely glucose-lowering agents but are integral to the broader management of cardiovascular risk in patients with type 2 diabetes mellitus.The study by GrubićRotkvićet al contributes to the growing body of literature supporting the early use of SGLT2i in patients with diabetic cardiomyopathy,offering a potential strategy to mitigate the progression of HF.Future larger studies should be con-ducted to confirm these findings,and explore the long-term cardiovascular bene-fits of SGLT2i,particularly in asymptomatic patients at risk of developing HF.

Effectiveness and mechanisms of sodium-dependent glucose transporter 2 inhibitors in type 2 diabetes and heart failure patients

We comment on an article by GrubićRotkvićet al published in the recent issue of the World Journal of Cardiology.We specifically focused on possible factors affecting the therapeutic effectiveness of sodium-dependent glucose transporter inhibitors(SGLT2i)in patients with type 2 diabetes mellitus(T2DM)and their impact on comorbidities.SGLT2i inhibits SGLT2 in the proximal tubules of the kidneys,lowering blood glucose levels by inhibiting glucose reabsorption by the kidneys and causing excess glucose to be excreted in the urine.Previous studies have demonstrated a role of SGLT2i in cardiovascular function in patients with diabetes who take metformin but still have poor glycemic control.In addition,SGLT2i has been shown to be effective in anti-apoptosis,weight loss,and cardiovascular protection.Accordingly,it is feasible to treat patients with T2DM with cardiovascular or renal diseases using SGLT2i.

Icariin ameliorates memory deficits through regulating brain insulin signaling and glucose transporters in 3×Tg-AD mice

Icariin,a major prenylated flavonoid found in Epimedium spp.,is a bioactive constituent of Herba Epimedii and has been shown to exert neuroprotective effects in experimental models of Alzheimer’s disease.In this study,we investigated the neuroprotective mechanism of icariin in an APP/PS1/Tau triple-transgenic mouse model of Alzheimer’s disease.We performed behavioral tests,pathological examination,and western blot assay,and found that memory deficits of the model mice were obviously improved,neuronal and synaptic damage in the cerebral cortex was substantially mitigated,and amyloid-βaccumulation and tau hyperphosphorylation were considerably reduced after 5 months of intragastric administration of icariin at a dose of 60 mg/kg body weight per day.Furthermore,deficits of proteins in the insulin signaling pathway and their phosphorylation levels were significantly reversed,including the insulin receptor,insulin receptor substrate 1,phosphatidylinositol-3-kinase,protein kinase B,and glycogen synthase kinase 3β,and the levels of glucose transporter 1 and 3 were markedly increased.These findings suggest that icariin can improve learning and memory impairments in the mouse model of Alzheimer’s disease by regulating brain insulin signaling and glucose transporters,which lays the foundation for potential clinical application of icariin in the prevention and treatment of Alzheimer’s disease.

Selective deletion of zinc transporter 3 in amacrine cells promotes retinal ganglion cell survival and optic nerve regeneration after injury

Vision depends on accurate signal conduction from the retina to the brain through the optic nerve,an important part of the central nervous system that consists of bundles of axons originating from retinal ganglion cells.The mammalian optic nerve,an important part of the central nervous system,cannot regenerate once it is injured,leading to permanent vision loss.To date,there is no clinical treatment that can regenerate the optic nerve and restore vision.Our previous study found that the mobile zinc(Zn^(2+))level increased rapidly after optic nerve injury in the retina,specifically in the vesicles of the inner plexiform layer.Furthermore,chelating Zn^(2+)significantly promoted axonal regeneration with a long-term effect.In this study,we conditionally knocked out zinc transporter 3(ZnT3)in amacrine cells or retinal ganglion cells to construct two transgenic mouse lines(VGAT^(Cre)ZnT3^(fl/fl)and VGLUT2^(Cre)ZnT3^(fl/fl),respectively).We obtained direct evidence that the rapidly increased mobile Zn^(2+)in response to injury was from amacrine cells.We also found that selective deletion of ZnT3 in amacrine cells promoted retinal ganglion cell survival and axonal regeneration after optic nerve crush injury,improved retinal ganglion cell function,and promoted vision recovery.Sequencing analysis of reginal ganglion cells revealed that inhibiting the release of presynaptic Zn^(2+)affected the transcription of key genes related to the survival of retinal ganglion cells in postsynaptic neurons,regulated the synaptic connection between amacrine cells and retinal ganglion cells,and affected the fate of retinal ganglion cells.These results suggest that amacrine cells release Zn^(2+)to trigger transcriptomic changes related to neuronal growth and survival in reginal ganglion cells,thereby influencing the synaptic plasticity of retinal networks.These results make the theory of zinc-dependent retinal ganglion cell death more accurate and complete and provide new insights into the complex interactions between retinal cell networks.

Vacuolar Phosphate Transporter1 (VPT1) may transport sugar in response to soluble sugar status of grape fruits

Vacuolar Phosphate Transporter1(VPT1)-mediated phosphate uptake in the vacuoles is essential to plant development and fruit ripening.Interestingly,here we find that the VPT1 may transport sugar in response to soluble sugar status of fruits.The VvVPT1 protein isolated from grape(Vitis vinifera)berrieswas tonoplast-localized and contains SPX(Syg1/Pho81/XPR1)and MFS(major facilitator superfamily)domains.Its mRNA expression was significantly increased during fruit ripening and induced by sucrose.Functional analyses based on transient transgenic systems in grape berry showed that VvVPT1 positively regulated berry ripening and significantly affected hexose contents,fruit firmness,and ripening-related gene expression.The VPT1 proteins(Grape VvVPT1,strawberry FaVPT1,and Arabidopsis AtVPT1)all showed low affinity for phosphate verified in yeast system,while they appear different in sugar transport capacity,consistent with fruit sugar status.Thus,our findings reveal a role for VPT1 in fruit ripening,associated to its SPX and MFS domains in direct transport of soluble sugar available into the vacuole,and open potential avenues for genetic improvement in fleshy fruit.

Functional analysis of MdSUT2.1,a plasma membrane sucrose transporter from apple

Sugar content is a determinant of apple(Malus×domestica Borkh.)sweetness.However,the molecular mechanism underlying sucrose accumulation in apple fruit remains elusive.Herein,this study reported the role of the sucrose transporter MdSUT2.1 in the regulation of sucrose accumulation in apples.The MdSUT2.1 gene encoded a protein with 612 amino acid residues that could be localized at the plasma membrane when expressed in tobacco leaf protoplasts.MdSUT2.1 was highly expressed in fruit and was positively correlated with sucrose accumulation during apple fruit development.Moreover,complementary growth assays in a yeast mutant validated the sucrose transport activity of MdSUT2.1.MdSUT2.1 overexpression in apples and tomatoes resulted in significant increases in sucrose,fructose,and glucose contents compared to the wild type(WT).Further analysis revealed that the expression levels of sugar metabolism-and transport-related genes SUSYs,NINVs,FRKs,HXKs,and TSTs increased in apples and tomatoes with MdSUT2.1 overexpression compared to WT.Finally,unlike the tonoplast sugar transporters MdTST1 and MdTST2,the promoter of MdSUT2.1 was not induced by exogenous sugars.These findings provide valuable insights into the molecular mechanism underlying sugar accumulation in apples.

A single nucleotide substitution in the MATE transporter gene regulates plastochron and the many noded dwarf phenotype in barley(Hordeum vulgare L.)

In higher plants,the shoot apical meristem produces lateral organs in a regular spacing(phyllotaxy)and timing(plastochron).The molecular analysis of mutants associated with phyllotaxy and plastochron would increase our understanding of the mechanism of shoot architecture formation.In this study,we identified mutant mnd8ynp5 that shows an increased rate of leaf emergence and a larger number of nodes in combination with a dwarfed growth habit from an EMS-treated population of the elite barley cultivar Yangnongpi 5.Using a map-based cloning strategy,the mnd8 gene was narrowed down to a 6.7-kb genomic interval on the long arm of chromosome 5H.Sequence analysis revealed that a C to T single-nucleotide mutation occurred at the first exon(position 953)of HORVU5Hr1G118820,leading to an alanine(Ala)to valine(Val)substitution at the 318th amino acid site.Next,HORVU5Hr1G118820 was defined as the candidate gene of MND8 encoding 514 amino acids and containing two multidrug and toxic compound extrusion(MATE)domains.It is highly homologous to maize Bige1and has a conserved function in the regulation of plant development by controlling the leaf initiation rate.Examination of modern barely varieties showed that Hap-1 was the dominant haplotype and was selected in barley breeding around the world.Collectively,our results indicated that mnd8ynp5 is a novel allele of the HORVU5Hr1G118820 gene that is possibly responsible for the shortened plastochron and many noded dwarf phenotype in barley.

Identification and expression analysis of sugar transporter family genes reveal the role of ZmSTP2 and ZmSTP20 in maize disease resistance

Sugar is an indispensable source of energy for plant growth and development, and it requires the participation of sugar transporter proteins(STPs) for crossing the hydrophobic barrier in plants. Here, we systematically identified the genes encoding sugar transporters in the genome of maize(Zea mays L.), analyzed their expression patterns under different conditions, and determined their functions in disease resistance. The results showed that the mazie sugar transporter family contained 24 members, all of which were predicted to be distributed on the cell membrane and had a highly conserved transmembrane transport domain. The tissue-specific expression of the maize sugar transporter genes was analyzed, and the expression level of these genes was found to be significantly different in different tissues. The analysis of biotic and abiotic stress data showed that the expression levels of the sugar transporter genes changed significantly under different stress factors. The expression levels of Zm STP2 and Zm STP20 continued to increase following Fusarium graminearum infection. By performing disease resistance analysis of zmstp2 and zmstp20 mutants, we found that after inoculation with Cochliobolus carbonum, Setosphaeria turcica, Cochliobolus heterostrophus, and F. graminearum, the lesion area of the mutants was significantly higher than that of the wild-type B73 plant. In this study, the genes encoding sugar transporters in maize were systematically identified and analyzed at the whole genome level. The expression patterns of the sugar transporter-encoding genes in different tissues of maize and under biotic and abiotic stresses were revealed, which laid an important theoretical foundation for further elucidation of their functions.

Peptide Transporter OsNPF8.1 Contributes to Sustainable Growth under Salt and Drought Stresses,and Grain Yield under Nitrogen Deficiency in Rice

Peptide transport is important for plant tissues where rapid proteolysis occurs,especially during germination and senescence,to enhance redistribution of organic nitrogen(N).However,the biological role of peptide transporters is poorly investigated in rice.We characterized the function of the peptide transporter OsNPF8.1 of rice nitrate transporter 1/peptide transporter family(NPF).Ectopic expression of OsNPF8.1 in yeast revealed that OsNPF8.1 encoded a high-affinity di-/tri-peptide transporter,and the osnpf8.1 mutants had a lower uptake rate of the fluorescent-labelled dipeptide c in leaves of rice seedlings.Histochemical assays showed that OsNPF8.1 was highly expressed in mesophyll cells and vascular parenchyma cells,but not detected in root hairs and epidermises.Expression of OsNPF8.1 was induced by N deficiency,drought,Na Cl and abscisic acid,and kept at a high level in senescing leaves.Under N deficiency conditions,compared with the wild type Zhonghua 11,the osnpf8.1 mutants grew slower at the seedling stage,and had lower grain yield and lower N content in the grains.In contrast,OsNPF8.1-over-expressing rice(OsNPF8.1-OE)grew faster at the seedling stage and had a higher grain yield.The osnpf8.1 seedlings were less tolerant to salt and drought stresses.These results suggested that stress-induced organic N transportation mediated by OsNPF8.1 might contribute to balance plant growth and tolerate to salt/drought stress and N-deficiency.