A MADS-box gene is involved in soybean resistance to multiple Soybean mosaic virus strains

Soybean mosaic virus(SMV)is a member of the genus Potyvirus that extensively impairs global soybean production.The full-length coding sequence of the MADS-box transcription factor Gm CAL was cloned from the SMV-resistant soybean cultivar Kefeng 1.SMV-induced expression analysis indicated that Gm CAL responded quickly to SMV-SC8 infection in Kefeng 1 but not in NN1138-2.Gm CAL was expressed at high levels in flowers and pods but at lower levels in leaves.The gene was localized to the nucleus by subcellular localization assay.Virus-induced gene silencing did not increase the accumulation of SMV in Gm CAL-silenced Kefeng 1 plants(with silencing efficiency~80%)after SC8 inoculation.Gm CAL-silencing plants still conferred resistance to SC8 that might be owing to incomplete silencing of genes with lower expression.SMV content decreased significantly in Gm CAL-overexpressing NN1138-2 plants after SMVSC3,SMV-SC7,and SMV-SC8 inoculation in comparison with a vector control,showing that overexpression of Gm CAL conferred broad-spectrum resistance to multiple SMV strains.These results confirm that Gm CAL,a key regulator but not a specific SC8 resistance gene(Rsc8),is a positive regulatory transcription factor involved in soybean resistance to SMV.

Construction of a Full-Length cDNA Library of Gossypium hirsutum L. and Identification of Two MADS-Box Genes

A full-length normalized cDNA library for the flower development stages of short-season cotton （Gossypium hirsutum L.） （CCRI36） was constructed. A total of 3 421 clones were randomly selected for sequencing, with a total of 3 175 effective sequences obtained after removal of empty-carriers and low-quality sequences. Clustering the 3 175 high-quality expressed sequence tags （ESTs） resulted in a set of 2 906 non-redundant sequences comprised of 233 contigs and 2 673 singletons. Comparative analyses indicated that 913 （43.6%） of the unigenes had homologues with function-known genes or functionassumed genes in the National Center for Biotechnology Information. In addition, 763 （36.4%） of the unigenes were functionally classified using Gene Ontology hierarchy. Through EST alignment and the screening method, the full-length cDNA of two MADS-box genes viz., GhMADSll and GhMADS12 were acquired. These genes may play a role in flower development. Phylogenetie analysis indicated that GhMADS11 and GhMADS12 had high homology and close evolutionary relationship with AGL2/SEP-type and PI-type genes, respectively. The expression of both GhMADSll and GhMADS12, genes was high in reproductive organs. In floral organs, GhMADSll expression was high in petals （whor12） and ovules, while GhMADS12 expression was high in petals （whor12） and stamens （whor13）. Results show that the EST strategy based on a normalized cDNA library is an effective method for gene identification. The study provides more insights for future molecular research on the regulation mechanism of cotton flower development.

Characterization of the Promoter of a Homolog of Maize MADS-Box Gene m18

Maize （Zea mays L.） is one of the world’s major food crops, and often suffers from tremendous yield loss caused by abiotic stresses. The MADS-box genes are known to play versatile roles in plants, controlling plant responses to multiple abiotic stresses. However, understanding of regulation of their expressions by the conventional loss-of-function approach is very dififcult. So far, regulation of MADS-box gene expression is little known. The best approach to retrieve expression regulation of this category of genes is to characterize expression of their promoters. In this study, the promoter of a homolog （GenBank accession no. EC864166） of maize MADS-box gene m18 was cloned by way of genome-walking PCR, named Pro66. Predicative analysis indicated that Pro66 contains more than one TATA box and multiple cis-acting environmental conditions-responsive elements （ECREs）. Pro66 could drive expression of theβ-glucuronidase （GUS）-encoding gene in maize, and heterologous expression of GUS in red pepper stressed by water deifcit, salt, copper, iron deifciency, heat, cold, and grown under short and long photoperiods, echoing predicative ECREs. Conclusively, maize MADS-box gene m18 likely plays versatile functions in maize response to multiple abiotic stresses due to the promoter with multiple cis-acting elements. The complex arrangement of multiple cis-acting elements in the promoter features meticulously regulated expression of m18. The results give informative clues for heterologous utilisation of the promoters in monocot and dicot species. The copy of the ECREs and heterologous expression of the promoter in dicot species are also discussed.

The Influence of Photoperiod on the Regulation of Root and Callus Initiation of Perle Noir (<i>V. vinifera</i>L.): Expression of MADS-Box Gene

To study the influence of photoperiod on roots differentiation in the Tunisian grapevine (Vitis vinifera L.) cultivar Perle noir, roots and callus initiation were analyzed under three different conditions of day length: long day (LD), short day (SD) and darkness (D). The photoperiod influenced the number of callus and roots per cuttings;it has a significant effect on the roots and callus initiation. Expression profile analysis of six MADS-box genes (VTM8, VSEP2, VAG12, VAG17-1, VAG17-2 and VSOC1.3) during root and callus development is in agreement with the above-mentioned observation. The expression of the MADS-box genes during root and callus development fluctuated in a tissue-dependent manner. These data suggest that all genes are expressed in roots under three photoperiods. Total darkness gives the number of the most important root per cutting compared to the other two conditions. This photoperiodic condition gave the most important expression of the studied genes VAG12, VAG17-2, VAG17-1, VTM8 and VSEP2 transcripts were not found in callus grown in the dark or in LD conditions, respectively. VSOC1.3 transcripts were not found in callus grown in the dark or in SD conditions, respectively. Transcript abundance of VTM8 and VSOC1 was highest in LD.

Analysis of MIKC^C-Type MADS-Box Gene Family in Gossypium hirsutum

MIKCC-type MADS-box genes encode transcription factors that are involved in plant developmental control and signal transduction. Few Gossypium hirsutum MADS-box genes have been reported thus far. Recently, the genome of Gossypium raimondii, considering the contributor of the D subgenome to G. hirsutum, was sequenced and provided a valuable resource to identify and analyze multiple MADS-box genes in G. hirsutum. Here we comprehensively analyzed 53 MIKCC-type MADS-box genes, including 34 newly cloned genes. Phylogenetic analysis of these genes with those from Arabidopsis and grapevine showed that the FLC and AGL12 subfamilies were absent in G. hirsutum. Proteins within a gene subfamily tended to share conserved motifs, and large differences occurred among subfamilies. Expression analysis in multiple tissues and lforal organs implied differing roles for the subfamilies in G. hirsutum. At nine loci, two or three genes co-occurred, indicating that they came from different subgenomes; these groups had similar expression patterns. The identiifcation of MIKCC-type MADS-box genes in G. hirsutum provides a valuable resource for further research into lfowering time, lfower development and ovule development in this important crop plant.

Peripheral blood RNA biomarkers can predict lesion severity in degenerative cervical myelopathy

Degenerative cervical myelopathy is a common cause of spinal cord injury,with longer symptom duration and higher myelopathy severity indicating a worse prognosis.While numerous studies have investigated serological biomarkers for acute spinal cord injury,few studies have explored such biomarkers for diagnosing degenerative cervical myelopathy.This study involved 30 patients with degenerative cervical myelopathy(51.3±7.3 years old,12 women and 18 men),seven healthy controls(25.7±1.7 years old,one woman and six men),and nine patients with cervical spondylotic radiculopathy(51.9±8.6 years old,three women and six men).Analysis of blood samples from the three groups showed clear differences in transcriptomic characteristics.Enrichment analysis identified 128 differentially expressed genes that were enriched in patients with neurological disabilities.Using least absolute shrinkage and selection operator analysis,we constructed a five-gene model(TBCD,TPM2,PNKD,EIF4G2,and AP5Z1)to diagnose degenerative cervical myelopathy with an accuracy of 93.5%.One-gene models(TCAP and SDHA)identified mild and severe degenerative cervical myelopathy with accuracies of 83.3%and 76.7%,respectively.Signatures of two immune cell types(memory B cells and memory-activated CD4^(+)T cells)predicted levels of lesions in degenerative cervical myelopathy with 80%accuracy.Our results suggest that peripheral blood RNA biomarkers could be used to predict lesion severity in degenerative cervical myelopathy.

The autophagy-lysosome pathway:a potential target in the chemical and gene therapeutic strategies for Parkinson’s disease

Parkinson’s disease is a common neurodegenerative disease with movement disorders associated with the intracytoplasmic deposition of aggregate proteins such asα-synuclein in neurons.As one of the major intracellular degradation pathways,the autophagy-lysosome pathway plays an important role in eliminating these proteins.Accumulating evidence has shown that upregulation of the autophagy-lysosome pathway may contribute to the clearance ofα-synuclein aggregates and protect against degeneration of dopaminergic neurons in Parkinson’s disease.Moreover,multiple genes associated with the pathogenesis of Parkinson’s disease are intimately linked to alterations in the autophagy-lysosome pathway.Thus,this pathway appears to be a promising therapeutic target for treatment of Parkinson’s disease.In this review,we briefly introduce the machinery of autophagy.Then,we provide a description of the effects of Parkinson’s disease–related genes on the autophagy-lysosome pathway.Finally,we highlight the potential chemical and genetic therapeutic strategies targeting the autophagy–lysosome pathway and their applications in Parkinson’s disease.

Dysregulation of genes involved in the long-chain fatty acid transport in pancreatic ductal adenocarcinoma

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is an aggressive lethal malignancy with limited options for treatment and a 5-year survival rate of 11%in the United States.As for other types of tumors,such as colorectal cancer,aberrant de novo lipid synthesis and reprogrammed lipid metabolism have been suggested to be associated with PDAC development and progression.AIM To identify the possible involvement of lipid metabolism in PDAC by analyzing in tumoral and non-tumoral tissues the expression level of the most relevant genes involved in the long-chain fatty acid(FA)import into cell.METHODS A gene expression analysis of FASN,CD36,SLC27A1,SLC27A2,SLC27A3,SLC27A4,SLC27A5,ACSL1,and ACSL3 was performed by qRT-PCR in 24 tumoral PDAC tissues and 11 samples from non-tumoral pancreatic tissues obtained via fine needle aspiration or via surgical resection.The genes were considered significantly dysregulated between the groups when the p value was<0.05 and the fold change(FC)was≤0.5 and≥2.RESULTS We found that three FA transporters and two long-chain acyl-CoA synthetases genes were significantly upregulated in the PDAC tissue compared to the non-tumoral tissue:SLC27A2(FC=5.66;P=0.033),SLC27A3(FC=2.68;P=0.040),SLC27A4(FC=3.13;P=0.033),ACSL1(FC=4.10;P<0.001),and ACSL3(FC=2.67;P=0.012).We further investigated any possible association between the levels of the analyzed mRNAs and the specific characteristics of the tumors,including the anatomic location,the lymph node involvement,and the presence of metastasis.A significant difference in the expression of SLC27A3(FC=3.28;P=0.040)was found comparing patients with and without lymph nodes involvement with an overexpression of this transcript in 17 patients presenting tumoral cells in the lymph nodes.CONCLUSION Despite the low number of patients analyzed,these preliminary results seem to be promising.Addressing lipid metabolism through a broad strategy could be a beneficial way to treat this malignancy.Future in vitro and in vivo studies on these genes may offer important insights into the mechanisms linking PDAC with the long-chain FA import pathway.

Recovery of the injured neural system through gene delivery to surviving neurons in Parkinson’s disease

A critical unaddressed problem in Parkinson’s disease is the lack of therapy that slows or hampers neurodegeneration.While medications effectively manage symptoms,they offer no long-term benefit because they fail to address the underlying neuronal loss.This highlights that the elusive goals of halting progression and restoring damaged neurons limit the long-term impact of current approaches.Recent clinical trials using gene therapy have demonstrated the safety of various vector delivery systems,dosages,and transgenes expressed in the central nervous system,signifying tangible and substantial progress in applying gene therapy as a promising Parkinson’s disease treatment.Intriguingly,at diagnosis,many dopamine neurons remain in the substantia nigra,offering a potential window for recovery and survival.We propose that modulating these surviving dopamine neurons and axons in the substantia nigra and striatum using gene therapy offers a potentially more impactful therapeutic approach for future research.Moreover,innovative gene therapies that focus on preserving the remaining elements may have significant potential for enhancing long-term outcomes and the quality of life for patients with Parkinson’s disease.In this review,we provide a perspective on how gene therapy can protect vulnerable elements in the substantia nigra and striatum,offering a novel approach to addressing Parkinson’s disease at its core.

AAV2-PDE6B restores retinal structure and function in the retinal degeneration 10 mouse model of retinitis pigmentosa by promoting phototransduction and inhibiting apoptosis

Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death.However,there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation.Adeno-associated virus(AAV)-mediated gene therapy is a promising strategy for treating retinitis pigmentosa.The aim of this study was to explore the molecular mechanisms by which AAV2-PDE6B rescues retinal function.To do this,we injected retinal degeneration 10(rd10)mice subretinally with AAV2-PDE6B and assessed the therapeutic effects on retinal function and structure using dark-and light-adapted electroretinogram,optical coherence tomography,and immunofluorescence.Data-independent acquisition-mass spectrometry-based proteomic analysis was conducted to investigate protein expression levels and pathway enrichment,and the results from this analysis were verified by real-time polymerase chain reaction and western blotting.AAV2-PDE6B injection significantly upregulated PDE6βexpression,preserved electroretinogram responses,and preserved outer nuclear layer thickness in rd10 mice.Differentially expressed proteins between wild-type and rd10 mice were closely related to visual perception,and treating rd10 mice with AAV2-PDE6B restored differentially expressed protein expression to levels similar to those seen in wild-type mice.Kyoto Encyclopedia of Genes and Genome analysis showed that the differentially expressed proteins whose expression was most significantly altered by AAV2-PDE6B injection were enriched in phototransduction pathways.Furthermore,the phototransductionrelated proteins Pde6α,Rom1,Rho,Aldh1a1,and Rbp1 exhibited opposite expression patterns in rd10 mice with or without AAV2-PDE6B treatment.Finally,Bax/Bcl-2,p-ERK/ERK,and p-c-Fos/c-Fos expression levels decreased in rd10 mice following AAV2-PDE6B treatment.Our data suggest that AAV2-PDE6B-mediated gene therapy promotes phototransduction and inhibits apoptosis by inhibiting the ERK signaling pathway and upregulating Bcl-2/Bax expression in retinitis pigmentosa.

Heterogeneity of mature oligodendrocytes in the central nervous system

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous system.Recent evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to axons.Despite the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is lacking.We delve into early 20th-century studies by Robertson and Río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature oligodendrocytes.Indeed,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination preferences.Furthermore,modern molecular investigations,employing techniques such as single cell/nucleus RNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system region.Age and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric disorders.Nevertheless,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined investigations.Future studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte heterogeneity.Such research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,hold promise for the development of therapeutic interventions targeting varied central nervous system pathology.

Pan-TRK positive uterine sarcoma in immunohistochemistry without neurotrophic tyrosine receptor kinase gene fusions:A case report

BACKGROUND The classification of uterine sarcomas is based on distinctive morphological and immunophenotypic characteristics,increasingly supported by molecular genetic diagnostics.Data on neurotrophic tyrosine receptor kinase(NTRK)gene fusionpositive uterine sarcoma,potentially aggressive and morphologically similar to fibrosarcoma,are limited due to its recent recognition.Pan-TRK immunohistochemistry(IHC)analysis serves as an effective screening tool with high sensitivity and specificity for NTRK-fusion malignancies.CASE SUMMARY We report a case of a malignant mesenchymal tumor originating from the uterine cervix,which was pan-TRK IHC-positive but lacked NTRK gene fusions,accompanied by a brief literature review.A 55-year-old woman presented to the emergency department with abdominal pain and distension,exhibiting significant ascites and multiple solid pelvic masses.Pelvic examination revealed a tumor encompassing the uterine cervix,extending to the vagina and uterine corpus.A punch biopsy of the cervix indicated NTRK sarcoma with positive immunochemical pan-TRK stain.However,subsequent next generation sequencing revealed no NTRK gene fusion,leading to a diagnosis of poorly differentiated,advanced-stage sarcoma.CONCLUSION The clinical significance of NTRK gene fusion lies in potential treatment with TRK inhibitors for positive sarcomas.Identifying such rare tumors is crucial due to the potential applicability of tropomyosin receptor kinase inhibitor treatment.

Genetic and epigenetic alterations associated with gestational diabetes mellitus and adverse neonatal outcomes

Gestational diabetes mellitus(GDM)is a metabolic disorder,recognised during 24-28 weeks of pregnancy.GDM is linked with adverse newborn outcomes such as macrosomia,premature delivery,metabolic disorder,cardiovascular,and neurological disorders.Recent investigations have focused on the correlation of genetic factors such asβ-cell function and insulin secretary genes(transcription factor 7 like 2,potassium voltage-gated channel subfamily q member 1,adipo-nectin etc.)on maternal metabolism during gestation leading to GDM.Epigenetic alterations like DNA methylation,histone modification,and miRNA expression can influence gene expression and play a dominant role in feto-maternal meta-bolic pathways.Interactions between genes and environment,resulting in differ-ential gene expression patterns may lead to GDM.Researchers suggested that GDM women are more susceptible to insulin resistance,which alters intrauterine surroundings,resulting hyperglycemia and hyperinsulinemia.Epigenetic modi-fications in genes affecting neuroendocrine activities,and metabolism,increase the risk of obesity and type 2 diabetes in offspring.There is currently no treatment or effective preventive method for GDM,since the molecular processes of insulin resistance are not well understood.The present review was undertaken to un-derstand the pathophysiology of GDM and its effects on adverse neonatal out-comes.In addition,the study of genetic and epigenetic alterations will provide lead to researchers in the search for predictive molecular biomarkers.

Autophagy-targeting modulation to promote peripheral nerve regeneration

Nerve regeneration following traumatic peripheral nerve injuries and neuropathies is a complex process modulated by diverse factors and intricate molecular mechanisms.Past studies have focused on factors that stimulate axonal outgrowth and myelin regeneration.However,recent studies have highlighted the pivotal role of autophagy in peripheral nerve regeneration,particularly in the context of traumatic injuries.Consequently,autophagy-targeting modulation has emerged as a promising therapeutic approach to enhancing peripheral nerve regeneration.Our current understanding suggests that activating autophagy facilitates the rapid clearance of damaged axons and myelin sheaths,thereby enhancing neuronal survival and mitigating injury-induced oxidative stress and inflammation.These actions collectively contribute to creating a favorable microenvironment for structural and functional nerve regeneration.A range of autophagyinducing drugs and interventions have demonstrated beneficial effects in alleviating peripheral neuropathy and promoting nerve regeneration in preclinical models of traumatic peripheral nerve injuries.This review delves into the regulation of autophagy in cell types involved in peripheral nerve regeneration,summarizing the potential drugs and interventions that can be harnessed to promote this process.We hope that our review will offer novel insights and perspectives on the exploitation of autophagy pathways in the treatment of peripheral nerve injuries and neuropathies.

AAV-mediated expression of p65shRNA and bone morphogenetic protein 4 synergistically enhances chondrocyte regeneration

BACKGROUND:Adeno-associated virus(AAV)gene therapy has been proven to be reliable and safe for the treatment of osteoarthritis in recent years.However,given the complexity of osteoarthritis pathogenesis,single gene manipulation for the treatment of osteoarthritis may not produce satisfactory results.Previous studies have shown that nuclear factorκB could promote the inflammatory pathway in osteoarthritic chondrocytes,and bone morphogenetic protein 4(BMP4)could promote cartilage regeneration.OBJECTIVE:To test whether combined application of AAV-p65shRNA and AAV-BMP4 will yield the synergistic effect on chondrocytes regeneration and osteoarthritis treatment.METHODS:Viral particles containing AAV-p65-shRNA and AAV-BMP4 were prepared.Their efficacy in inhibiting inflammation in chondrocytes and promoting chondrogenesis was assessed in vitro and in vivo by transfecting AAV-p65-shRNA or AAV-BMP4 into cells.The experiments were divided into five groups:PBS group;osteoarthritis group;AAV-BMP4 group;AAV-p65shRNA group;and BMP4-p65shRNA 1:1 group.Samples were collected at 4,12,and 24 weeks postoperatively.Tissue staining,including safranin O and Alcian blue,was applied after collecting articular tissue.Then,the optimal ratio between the two types of transfected viral particles was further investigated to improve the chondrogenic potential of mixed cells in vivo.RESULTS AND CONCLUSION:The combined application of AAV-p65shRNA and AAV-BMP4 together showed a synergistic effect on cartilage regeneration and osteoarthritis treatment.Mixed cells transfected with AAV-p65shRNA and AAV-BMP4 at a 1:1 ratio produced the most extracellular matrix synthesis(P<0.05).In vivo results also revealed that the combination of the two viruses had the highest regenerative potential for osteoarthritic cartilage(P<0.05).In the present study,we also discovered that the combined therapy had the maximum effect when the two viruses were administered in equal proportions.Decreasing either p65shRNA or BMP4 transfected cells resulted in less collagen II synthesis.This implies that inhibiting inflammation by p65shRNA and promoting regeneration by BMP4 are equally important for osteoarthritis treatment.These findings provide a new strategy for the treatment of early osteoarthritis by simultaneously inhibiting cartilage inflammation and promoting cartilage repair.

Duplication and Divergence of Floral MADS-Box Genes in Grasses： Evidence for the Generation and Modification of Novel Regulators

The process of flowering is controlled by a hierarchy of floral genes that act as flowering time genes, inflorescence/floral meristem Identity genes, and/or floral organ-identity genes. The most important and well-characterized floral genes are those that belong to the MADS-box family of transcription factors. Compelling evidence suggests that floral MADS-box genes have experienced a few large-scale duplication events. In particular, the precore eudicot duplication events have been considered to correlate with the emergence and diversification of core eudicots. Duplication of floral MADS-box genes has also been documented in monocots, particularly In grasses, although a systematic study is lacking. In the present study, by conducting extensive phylogenetlc analyses, we identified pre-Poaceae gene duplication events in each of the AP1, P1, AG, AGL11, AGL2/3/4, and AGL9gene lineages. Comparative genomic studies further indicated that some of these duplications actually resulted from the genome doubling event that occurred 66-70 million years ago （MYA）. In addition, we found that after gene duplication, exonization （of intron sequences） and pseudoexonization （of exon sequences） have contributed to the divergence of duplicate genes in sequence structure and, possibly, gene function.

Genome Sequencing Reveals the Role of MADS-box Gene Families in the Floral Morphology Evolution of Orchids

Orchid origin and evolution are common topics in evolutionary biology. Orchidaceae have approximately 30 000 orchid species distributed in diverse habitats and account for approximately 10% of the flowering plant species worldwide. Orchids provide us with materials to explore coevolution and organic evolution. In this review, we highlighted the genome study progress of orchids. In addition, we revealed the role of MADS-box gene families in the floral morphology and evolution of orchids. Genomics studies confirmed that all five subfamilies of existing orchids evolved from a common ancestor. Loss of Mβ MADS-box genes resulted in the endosperm from the seed of all existing orchids being absent. Perianth reversion to the ancestral state occurred because Apostasia and Apostasioideae lost B-AP3 and E class paralogous genes. Loss of P-subclade members of MIKC*-Type in Phalaenopsis equestris, Dendrobium catenatum, and Epidendroideae caused the formation of pollinium.In addition, the combined loss of AGL12 and contraction of ANR1 gave orchids the ability to be successfully epiphytic on trees or rocks and to develop a unique root system. Both pollinium and epiphytic production on trees are beneficial for orchid adaptations, and Epidendroideae evolved more species(~ 20 000) than Apostasioideae(16 species). Genome studies shed new light on determining the evolutionary history of orchids and understanding the genetic mechanisms of orchid morphological evolution.

灰毡毛忍冬MADS-box基因家族鉴定与CMB1基因克隆

目的鉴定灰毡毛忍冬Lonicera macranthoides MADS-box家族基因并进行生物信息学分析与表达模式验证,克隆湘蕾型和野生型灰毡毛忍冬MADS-box家族成员CMB1全长。方法基于转录组数据,利用在线工具对灰毡毛忍冬MADS-box进行生物信息学分析,并利用qRT-PCR验证MADS-box基因在不同品种中的表达模式,通过RT-PCR、RACE技术克隆湘蕾型和野生型灰毡毛忍冬CMB1基因全长。结果28个灰毡毛忍冬MADS-box蛋白长度为89~359 aa,碱性蛋白占比85.7%,不稳定蛋白占比96.4%,亲水性蛋白占比96.4%,均定位于细胞核,均为无跨膜结构的非分泌蛋白。转录组显示,与野生型比较,湘蕾型中28个MADS-box基因有17.86%表达下调,MIKCC型基因中有18.75%表达下调。克隆得到在两个品种的灰毡毛忍冬花中高度特异性表达的CMB1基因全长,均包含一个738 bp的ORF,编码245个氨基酸。CMB1基因在两个品种的花中表达量存在显著差异(P<0.01),且与茎、叶相比,在花中高度特异性表达(P<0.01)。结论基于灰毡毛忍冬转录组数据,鉴定了28个MADS-box家族基因,克隆得到湘蕾型与野生型灰毡毛忍冬CMB1基因全长,为进一步研究灰毡毛忍冬花发育、优良表型形成的分子机制提供研究基础与理论依据。

Molecular Cloning and Function Analysis of Two SQUAMOSA-Like MADS-Box Genes From Gossypium hirsutum L.

The MADS-box genes encode a large family of transcription factors having diverse roles in plant development. The SQUAMOSA （SQUA）/APETALA1 （AP1）/FRUITFULL （FUL） subfamily genes are essential regulators of floral transition and floral organ identity. Here we cloned two MADS-box genes, GhMADS22 and GhMADS23, belonging to the SQUA/AP1/FUL subgroup from Gossypium hirsutum L. Phylogenetic analysis and sequence alignment showed that GhMAD$22 and GhMADS23 belonged to the euFUL and euAP1 subclades, respectively. The two genes both had eight exons and seven introns from the start codon to the stop codon according to the alignment between the obtained cDNA sequence and the Gossypium raimondii L. genome sequence. Expression profile analysis showed that GhMADS22 and GhMADS23 were highly expressed in developing shoot apices, bracts, and sepals. Gibberellic acid promoted GhMADS22 and GhMADS23 expression in the shoot apex. Transgenic Arabidopsis lines overexpressing 35S：：GhMADS22 had abnormal flowers and bolted earlier than wild type under long-day conditions （16 h light/8 h dark）. Moreover, GhMADS22 over- expression delayed floral organ senescence and abscission and it could also respond to abscisic acid. In summary, GhMADS22 may have functions in promoting flowering, improving resistance and delaying senescence for cotton and thus it may be a candidate target for promoting early-maturation in cotton breeding.

Isolation and ectopic expression of a bamboo MADS-box gene

A cDNA named DlMADS18 was isolated from the young spikelets of the sweet bamboo, Dendrocalamus latiflorus by RACE. DNA sequence analysis showed that DlMADS18 was composed of full ORF and 3’UTR, but without 5’UTR. The cDNA contained 1039 nucleotides and encoded a putative protein of 249 amino acid residues. The gene displayed the structure of a typical plant MADS box gene, which consisted of an MADS domain, K domain, a short I region, and the C-terminal region. Phylogenetic analysis of plant MADS box genes based on amino acid se- quences revealed that DlMADS18 was grouped into the AGAMOUS-LIKE 6 (AGL6)-like subfamily. It was most likely homologous to the OsMADS6 of rice (Oryza sativa), with 88% sequence identity for the entire amino acid sequences. The DlMADS18 also showed relatively high amino acid sequence identity (59%) to AGL6 of Arabidopsis thaliana. To study the functions of DlMADS18, DlMADS18 cDNA clone driven by the CaMV 35S promoter was transformed into Arabidopsis plants. Transgenic plants of DlMADS18 exhibited the pheno- types of curled leaves, dwarfism, and early flowering with clustered terminal flowers. These results indicated that DlMADS18 may probably be involved in controlling the flowering time of D. latiflorus.