FIT interacts with AtbHLH38 and AtbHLH39 in regulating iron uptake gene expression for iron homeostasis in Arabidopsis

Iron is an essential element for plant growth and development. Iron homeostasis in plants is tightly regulated at both transcriptional and posttranscriptional level. Several bHLH transcription factors involved in iron homeostasis have been identified recently. However, their regulatory mechanisms remain unknown. In this work, we demonstrate that the transcription factor FIT interacted with AtbHLH38 and AtbHLH39 and directly conferred the expression regulation of iron uptake genes for iron homeostasis in Arabidopsis. Yeast two-hybrid analysis and transient expression in Arabidopsis protoplasts showed that AtbHLH38 or AtbHLH39 interacted with FIT, a central transcription factor involved in iron homeostasis in Arabidopsis. Expression of FIT/AtbHLH38 or FIT/AtbHLH39 in yeast cells activated GUS expression driven by ferric chelate reductase （FRO2） and ferrous transporter （IRT1） promoters. Overexpression of FITwith either AtbHLH38 or AtbHLH39 in plants converted the expression of the iron uptake genes FRO2 and IRT1 from induced to constitutive. Further analysis revealed that FRO2 and IRT1 were not regulated at the posttranscriptional level in these plants because IRT1 protein accumulation and high ferric chelate reductase activity were detected in the overexpression plants under both iron deficiency and iron sufficiency. The double overexpression plants accumulated more iron in their shoots than wild type or the plants overexpressing either AtbHLH38, AtbHLH39 or FIT. Our data support that ferric-chelate reductase FRO2 and ferrous-transporter IRT1 are the targets of the three transcription factors and the transcription of FRO2 and IRT1 is directly regulated by a complex of FIT/AtbHLH38 or FIT/AtbHLH39.

Assessment of the individual and combined effects of Rht8 and Ppd-D1a on plant height, time to heading and yield traits in common wheat

Grain yield in cereal crops is a complex trait controlled by multiple genes and influenced by developmental processes and environment. Here we report the effects of alleles Rht8 and Ppd-D1 a on plant height, time to heading, and grain yield and its component traits. Association analysis and quantitative trait locus mapping using phenotypic data from 15 environments led to the following conclusions. First, both Rht8 and Ppd-D1 a reduce plant height. However, Ppd-D1 a but not Rht8 causes earlier heading.Second, both Rht8 and Ppd-D1 a promote grain yield and affect component traits. Their combined effects are substantially larger than those conferred by either allele alone.Third, promotion of grain yield by Rht8 and Ppd-D1 a is through increasing fertile spikelet number. We speculate that Rht8 and Ppd-D1 a act independently and additively in control of plant height, grain yield and yield component. Combination of the two alleles is desirable for adjusting plant height and enhancing grain yield and abiotic stress tolerance.

Molecular genetic and genomic analysis of wheat milling and end-use traits in China:Progress and perspectives

Wheat is the most widely cultivated staple food crop, and multiple types of food derivatives are processed and consumed globally. Wheat grain quality(WGQ) is central to food processing and nutritional value, and is a decisive factor for consumer acceptance and commercial value of wheat cultivars. Hence, improvement in WGQ traits is top priority for both conventional and molecular wheat breeding. In this review we will focus on two important WGQ traits, grain milling and end-use, and will summarize recent progress in China. Chinese scientists have invested substantial effort in molecular genetic and genomic analysis of these traits and their effects on end-use properties. The insights and resources generated have contributed to the understanding and improvement of these traits. As high-quality genomics information and powerful genome engineering tools are becoming available for wheat, more fundamental breakthroughs in dissecting the molecular and genomic basis of WGQ are expected. China will strive to make further significant contributions to the study and improvement of WGQ in the genomics era.

Divergence in homoeolog expression of the grain length-associated gene GASR7 during wheat allohexaploidization

Hexaploid wheat has triplicated homoeologs for most of the genes that are located in subgenomes A, B, and D. GASR7, a member of the Snakin/GASA gene family, has been associated with grain length development in wheat. However, little is known about divergence of its homoeolog expression in wheat polyploids. We studied the expression patterns of the GASR7 homoeologs in immature seeds in a synthetic hexaploid wheat line whose kernels are slender like those of its maternal parent(Triticum turgidum, AABB, PI 94655) in contrast to the round seed shape of its paternal progenitor(Aegilops tauschii, DD, AS2404). We found that the B homoeolog of GASR7 was the main contributor to the total expression level of this gene in both the maternal tetraploid progenitor and the hexaploid progeny, whereas the expression levels of the A and D homoeologs were much lower. To understand possible mechanisms regulating different GASR7 homoeologs, we firstly analyzed the promoter sequences of three homoeologous genes and found that all of them contained gibberellic acid(GA) response elements, with the TaG ASR7 B promoter(pT aG ASR7B) uniquely characterized by an additional predicted transcriptional enhancer. This was confirmed by the GA treatment of spikes where all three homoeologs were induced, with a much stronger response for TaG ASR7 B. McrB C enzyme assays showed that the methylation status at pT aG ASR7 D was increased during allohexaploidization, consistent with the repressed expression of TaG ASR7 D. For pT aG ASR7 A, the distribution of repetitive sequence-derived 24-nucleotide(nt) small interfering RNAs(siR NAs) were found which suggests possible epigenetic regulation because 24-nt siR NAs are known to mediate RNA-dependent DNA methylation. Our results thus indicate that both genetic and epigenetic mechanisms may be involved in the divergence of GASR7 homoeolog expression in polyploid wheat.

Myocardial Infarction and Intracerebral Hemorrhage in a Chinese Population: Relationship with Lipoproteins and Adipokines

BACKGROUND: Adipokines and inflammatory factors play an important role in disease progression. Two cardiovascular diseases which have important contributions to mortality and morbidity in China are in-tracerebral hemorrhage (ICH) and myocardial infarction (MI). Acylation stimulating protein has been shown in North American populations to have strong associations with risk factors for MI. Complement C3 (C3) a component of the innate complement immune system is the precursor protein to ASP;C3 has been impli-cated in the pathogenesis of ICH. OBJECTIVE: In this case-control study we examined the association be-tween BMI, lipoproteins adiponectin, C3 and ASP) in a Chinese population. METHODS AND RESULTS: Three groups of subjects were studied: ICH group (N = 41), MI group (N = 60) and a control group (N = 44). There was no difference in BMI for either ICH or MI compared to controls (Control: 22.3 ± 0.3 kg/m2;ICH: 21.3 ± 0.4 vs MI: 22.5 ± 0.2, ICH and MI versus control pNS). The ICH group had lower LDL-C (Control: 3.21 ± 0.13 mmol/L;ICH: 2.54 ± 0.13;MI: 2.99 ± 0.13;ICH vs control p < 0.05), total cholesterol (Control: 5.06 ± 0.16 mmol/L;ICH: 4.40 ± 0.15;MI: 4.51 ± 0.14;ICH and MI vs control p < 0.05),, HDL-C (Control: 1.34 ± 0.05 mmol/L;ICH: 1.22 ± 0.06;MI: 0.95 ± 0.04;ICH and MI vs control p < 0.05), and C3 (Control: 2.58 ? 0.21 g/L;ICH: 1.85 ? 0.19;MI: 2.87 ? 0.16;ICH vs control p < 0.05), and higher TG (Control: 1.10 ± 0.07 mmol/L;ICH: 1.77 ± 0.17;MI: 1.61 ± 0.10, ICH and MI vs control p < 0.05), compared to the controls. The MI group had lower total cholesterol and HDL-C and higher TG and ASP (Control: 33.70 ? 2.07 nM;ICH: 35.10 ? 2.33;MI: 41.50 ? 1.81;MI vs control p < 0.05) compared to control. CONCLUSION: Chinese men and women who had an MI displayed elevated ASP unrelated to an increase in the precursor protein, C3. Chinese men and women with ICH had ASP levels similar to controls yet lower C3 suggesting that C3, and the regulation of C3 conversion to ASP may be important in ICH disease pathology.

Reactions of Triticum urartu accessions to two races of the wheat yellow rust pathogen

Triticum urartu(AA,2n=2x=14),a wild grass endemic to the Fertile Crescent(FC),is the progenitor of the A subgenome in common wheat.It belongs to the primary gene pool for wheat improvement.Here,we evaluated the yellow rust(caused by Puccinia striiformis f.sp.tritici,Pst)reactions of 147 T.urartu accessions collected from different parts of the FC.The reactions varied from susceptibility to strong resistance.In general,there were more accessions with stronger resistance to race CYR33 than to CYR 32.In most cases the main form of defense was a moderate resistance characterized by the presence of necrotic/chlorotic lesions with fewer Pst uredinia on the leaves.Forty two accessions displayed resistance to both races.Histological analysis showed that Pst growth was abundant in the compatible interaction but significantly suppressed by the resistant response.Gene silencing mediated by Barley stripe mosaic virus was effective in two T.urartu accessions with different resistance responses,indicating that this method can expedite future functional analysis of resistance genes.Our data suggest that T.urartu is a valuable source of resistance to yellow rust,and represents a model for studying the genetic,genomic and molecular basis underlying interaction between wheat and Pst.

Orchestrating seed storage protein and starch accumulation toward overcoming yield–quality trade-off in cereal crops

Achieving high yield and good quality in crops is essential for human food security and health.However,there is usually disharmony between yield and quality.Seed storage protein(SSP)and starch,the predominant components in cereal grains,determine yield and quality,and their coupled synthesis causes a yield–quality trade-off.Therefore,dissection of the underlying regulatory mechanism facilitates simultaneous improvement of yield and quality.Here,we summarize current findings about the synergistic molecular machinery underpinning SSP and starch synthesis in the leading staple cereal crops,including maize,rice and wheat.We further evaluate the functional conservation and differentiation of key regulators and specify feasible research approaches to identify additional regulators and expand insights.We also present major strategies to leverage resultant information for simultaneous improvement of yield and quality by molecular breeding.Finally,future perspectives on major challenges are proposed.

A novel recognition-transmission-execution module in maize immunity

Maize(Zea mays L.)stands as one of the most extensively cultivated crops worldwide[1].With its widespread cultivation comes a plethora of challenges,including diseases caused by a wide range of pathogens[2].Gray leaf spot(GLS)is a foliar disease that drastically reduces worldwide maize production.Since it wasfirst identified in the US in the 1920s,the disease has spread around the globe,severely affecting corn production.GLS is predominantly instigated from infection by Cercospora zeae-maydis and Cercospora zeina[3].In many parts of China,GLS is an important disease[4].In severe cases,GLS can lead to a reduction of yield by up to 40%.Hence,it is urgent to control the spread of this disease[3].Developing and utilizing pathogen-resistant crop cultivars is the most economical and environment-friendly measure for controlling plant diseases.Scientists have dedicated significant efforts to characterize GLS resistance genes in maize.To date,ZmCCoAOMT2(caffeoyl-CoA O-methyltransferase 2)and ZmMM1(Mexicana lesion mimic 1)are the only two genes that have been shown to confer resistance to GLS[5,6].However,to facilitate the development of resistant cultivars,there is an urgent need for additional genes that are effective against GLS and a clearer understanding of the molecular mechanisms underlying the regulation of host plant resistance to GLS.

LbCas12a-nuclease-mediated tiling deletion for large-scale targeted editing of non-coding regions in rice

Dear Editor,This study reports a nuclease-mediated tiling deletion(NTD)method that uses LbCas12a nuclease with a tiling CRISPRderived RNA(crRNA)library to efficiently induce numerous nucleotide deletions in non-coding regulatory regions of endogenous rice genes.This method was applied to non-coding regions of the Green Revolution gene SD1,generating 6 mutants with quantitative variations in plant height,which were then used to investigate associations between genotype and phenotype.NTD is thus a promising tool for molecular rice breeding.

CRISPR/CasΦ2-mediated gene editing in wheat and rye

The recent advancements in developing the CRISPR/Cas9 system and various derivative tools(e.g.,base editors)have accelerated basic plant science research and crop improvement by creating multiple types of genetic variations(Li et al.,2023a).

Immunopathogenesis and immunomodulatory therapy for myocarditis

Myocarditis is an inflammatory cardiac disease characterized by the destruction of myocardial cells, infiltration of interstitial inflammatory cells, and fibrosis, and is becoming a major public health concern. The aetiology of myocarditis continues to broaden as new pathogens and drugs emerge. The relationship between immune checkpoint inhibitors, severe acute respiratory syndrome coronavirus 2, vaccines against coronavirus disease-2019, and myocarditis has attracted increased attention. Immunopathological processes play an important role in the different phases of myocarditis, affecting disease occurrence, development, and prognosis. Excessive immune activation can induce severe myocardial injury and lead to fulminant myocarditis,whereas chronic inflammation can lead to cardiac remodelling and inflammatory dilated cardiomyopathy. The use of immunosuppressive treatments, particularly cytotoxic agents, for myocarditis, remains controversial. While reasonable and effective immunomodulatory therapy is the general trend. This review focuses on the current understanding of the aetiology and immunopathogenesis of myocarditis and offers new perspectives on immunomodulatory therapies.

Genome resources for the elite bread wheat cultivar Aikang 58 and mining of elite homeologous haplotypes for accelerating wheat improvement

Despite recent progress in crop genomics studies,the genomic changes brought about by modern breeding selection are still poorly understood,thus hampering genomics-assisted breeding,especially in polyploid crops with compound genomes such as common wheat(Triticum aestivum).In this work,we constructed genome resources for the modern elite common wheat variety Aikang 58(AK58).Comparative genomics between AK58 and the landrace cultivar Chinese Spring(CS)shed light on genomic changes that occurred through recent varietal improvement.We also explored subgenome diploidization and divergence in common wheat and developed a homoeologous locus-based genome-wide association study(HGWAS)approach,which was more effective than single homoeolog-based GWAS in unraveling agronomic trait-associated loci.A total of 123 major HGWAs loci were detected using a genetic population derived from AK58 and cs.Elite homoeologous haplotypes(HHs),formed by combinations of subgenomic homoeologs of the associated loci,were found in both parents and progeny,and many could substantially improve wheat yield and related traits.We built a website where users can download genome assembly sequence and annotation data for AK58,perform blast analysis,and run JBrowse.Our work enriches genome resources for wheat,provides new insights into genomic changes during modern wheat improve-.ment,and suggests that efficientmining of elite HHs can make a substantial contribuutionto genomics-assisted breeding in common wheat and other polyploid crops.

Rising from the dead: the power of genome editing

To protect themselves against diverse pathogens, plants have developed sophisticated defense mechanisms. Hypersensitive response or the rapid localized death of plant cells is a major defense strategy deployed by plants to kill the invading pathogens(Wu et al., 2014).

A new phase of treasure hunting in plant genebanks

The United Nations has estimated that the world population will surpass 8 billion on Nov.15,2022,and will continue to rise to 11.2 billion by 2100.Considering that agricultural resources are limited,it will be a huge challenge to produce sufficient food to feed such a rapidly rising global population.Furthermore,the ongoing climate changes are adding more pressures on worldwide crop productions.To cope with these problems,it is both imperative and urgent to develop the crop cultivars with higher yield potential,improved nutritional quality,and better resilience to environmental stresses.

揭开(L)WY结构域卵菌效应因子的神秘面纱

Oomycetes(“egg fungi”),also known as Water Molds,form a large group of filamentous microorganisms,including many plant pathogens that pose serious threats to global food security.The oomycete Phytophthora species have been listed among the most destructive plant pathogens due to their capacity to cause huge damages to global crop production.

Bioactivated and selective: A promising new family of nematicides with a novel mode of action

Plant parasitic nematodes(PPNs)are notorious agricultural and forestry pests;they have been estimated to cause over$157 billion USD of crop losses globally every year(Singh et al.,2015).However,the actual damage due to PPNs is likely much bigger than estimated.Wounds produced by PPNs can increase the susceptibility of crops to fungal,oomycete,bacterial,and viral pathogens.Furthermore,many nematode diseases,especially those associated with root-feeding nematodes,are difficult to diagnose and thus poorly managed in developing countries.

Launching, perceiving, and diminishing of airborne signals

Aphids are highly destructive pests that greatly hurt the agricultural industry.Transmitting over 40%of plant viruses,they are the most destructive pests that the agricultural industry faces(Gong et al.,2023).Aphids feed on plants,and in doing so,they consume sap from one plant and then move to another and inject their saliva into the new plant(Hooks and Fereres,2006).This cycle causes diseases and viral pathogens to become rampant between plants as the aphids carry viral pathogens from one plant to another and so on.

A life support-based comprehensive treatment regimen dramatically lowers the in-hospital mortality of patients with fulminant myocarditis: a multiple center study

Fulminant myocarditis(FM) has unacceptable high mortality. This study aimed to evaluate the therapeutic efficacy of a life support-based comprehensive treatment regimen(LSBCTR), a completely novel treatment regimen, for FM. A total of 169 FM patients recruited from January 2008 to December 2018 were divided into two groups: patients receiving LSBCTR(81 cases),which includes(i) mechanical life support(positive pressure respiration, intra-aortic balloon pump with or without extracorporeal membrane oxygenation),(ii) immunomodulation therapy using sufficient doses of glucocorticoids and immunoglobulins, and(iii) application of neuraminidase inhibitors, and those receiving conventional treatment(88 cases). The endpoints were in-hospital death and heart-transplantation. Of all the population, 44 patients(26.0%) died in hospitals. Inhospital mortality was 3.7%(3/81) for LSBCTR group and 46.6%(41/88) for traditional treatment(P<0.001). Early application of LSBCTR, mechanical life support, neuraminidase inhibitors, and immunomodulation therapy significantly contributed to reduction in in-hospital mortality. This study describes a novel treatment regimen for FM patients that dramatically reduces inhospital mortality. Its generalization and clinical application will efficiently save lives although further optimization is needed.This study offers an insight that virus infection induced inflammatory waterfall results in cardiac injury and cardiogenic shock and is the therapeutic target.

Transgenic expression of MYB15 confers enhanced sensitivity to abscisic acid and improved drought tolerance in Arabidopsis thaliana

Abiotic stresses cause serious crop losses. Knowledge on genes functioning in plant responses to adverse growth conditions is essential for developing stress tolerant crops. Here we report that transgenic expression of MYB15, encoding a R2R3 MYB transcription factor in Arabidopsis thaliana, conferred hypersensitivity to exogenous abscisic acid （ABA） and improved tolerance to drought and salt stresses. The promoter of MYB15 was active in not only vegetative and reproductive organs but also the guard cells of stomata. Its transcript level was substantially upregulated by ABA, drought or salt treatments. Compared with wild type （WT） control, MYB15 overexpression lines were hypersensitive to ABA in germination assays, more susceptible to ABA-elicited inhibition of root elongation, and more sensitive to ABA-induced stomatal closure. In line with the above findings, the transcript levels of ABA biosynthesis （ABA1, ABA2）, signaling （AB13） and responsive genes （AtADH1, RD22, RD29B, AtEM6） were generally higher in MYB15 overexpression seedlings than in WT controls after treatment with ABA. MYB15 overexpression lines displayed improved survival and reduced water loss rates than WT control under water deficiency conditions. These overexpression lines also displayed higher tolerance to NaCI stress. Collectively, our data suggest that overexpression of MYB15 improves drought and salt tolerance in Arabidopsis possibly by enhancing the expression levels of the genes involved in ABA biosynthesis and signaling, and those encoding the stress-protective proteins.

Chinese expert consensus statement on the diagnosis and treatment of fulminant myocarditis

Fulminant myocarditis is primarily caused by infection with any number of a variety of viruses. It arises quickly, progresses rapidly, and may lead to severe heart failure or circulatory failure presenting as rapid-onset hypotension and cardiogenic shock,with mortality rates as high as 50%–70%. Most importantly, there are no treatment options, guidelines or an expert consensus statement. Here, we provide the first expert consensus, the Chinese Society of Cardiology Expert Consensus Statement on the Diagnosis and Treatment of Fulminant Myocarditis, based on data from our recent clinical trial(NCT03268642). In this statement, we describe the clinical features and diagnostic criteria of fulminant myocarditis, and importantly, for the first time,we describe a new treatment regimen termed life support-based comprehensive treatment regimen. The core content of this treatment regimen includes(i) mechanical life support(applications of mechanical respirators and circulatory support systems,including intraaortic balloon pump and extracorporeal membrane oxygenation),(ii) immunological modulation by using sufficient doses of glucocorticoid, immunoglobulin and(iii) antiviral reagents using neuraminidase inhibitor. The proper application of this treatment regimen may and has helped to save the lives of many patients with fulminant myocarditis.