In order to explore the effects of abscisic acid(ABA)on monoterpene synthesis in grape berries,this study used table grape species‘Jingxiangyu'with muscat flavor as experimental material,and soaked the clusters with 300 mg · L-1 ABA twice at one week before and during veraison. The contents of free monoterpenoids at 7,14,21,28 and 35 days after first treatment were analyzed qualitatively and quantitatively by GC-MS. The results showed that 28 kinds of monoterpenes were detected in berries,most of which accumulated during ripening. The total contents of free monoterpenoids in treated berries at maturity was 45.20% higher than that in the control,and the substance that changed most strongly was linalool. To investigate how ABA regulate monoterpenes synthesis,quantitative real-time PCR was used. The results indicated that the expression of ABA synthesis genes(VvNCED1 and VvGT)was much stronger than that of the control. The relative expression of VvβG1 increased after ABA treatment constantly. The transcriptional levels of ABA receptor VvPYL1 and signal transduction related genes VvPP2C2,VvSnRK2.1 and VvABI5 were distinctly higher than the control on 21 and 35 days after treatment respectively. The expression levels of upstream genes about monoterpene synthesis(VvDXS2,VvDXS3,VvDXR,VvGPPS)and monoterpene synthase gene VvPNLinNer was significantly higher. According to the above results,it’s suggested that exogenous ABA enhance ABA signal transduction in berries,which lead to the increase of monoterpene substrate level and facilitate monoterpene synthesis,finally improve the quality of rose flavor grapes.
Brazil Sour Orange(Citrus aurantium L.),Bendizao Mandarin(C. reticulata Blanco),Guihuadinanfeng mandarin(C. reticulata Blanco),Jincheng Beibei 447[C. sinensis(L.)Osbeck] and other 30 germplasms were used for mining the transcription factors related to flavonoid biosynthesis. Comparative transcriptomic analysis revealed that ERF,MYB and Dof transcription factor families are significantly involved in metabolism of flavonoids during fruit development. Correlation analysis of the expressions of CitCHS2,a key gene of flavonoids biosynthesis with the differentially expressed genes from transcriptomic analysis indicated that two R2R3-MYB family member CitMYB21(Ciclev10021699m)and CitMYB33(Ciclev10012152m)were negatively correlated to expression of CitCHS2. Phylogenic analysis revealed that these two genes belong to SG2 and SG1 subgroup of R2R3-MYBs family,respectively. The full length of CitMYB21 coding region is 804 bp and encodes 267 amino acids. The expressions of CitMYB21 were highly tissue and genotype specific,and significantly negatively correlated with the flavonoids contents. Silence of CitMYB21 resulted a significant increase of flavonoids in the leaf of transgenic plants,while transient overexpression of CitMYB21 in the peel of citrus fruit led to a significant decrease of flavonoids. Results of this study indicated that expression of CitMYB21 negatively affect the flavonoid biosynthesis in citrus,suggesting CitMYB21 may be an important transcription factor negatively regulating the biosynthesis of flavonoid.
Young leaves of 168 pomegranate cultivars collected from the National Forest Germplasm Resource Repository for Pomegranate,Zaozhuang City,Shandong,China were used to construct their fingerprints using SSR molecular marker technique. Based on the fingerprint information,the maximum likelihood method(LOD)was applied to hybrid screening in open-pollinated progenies of the cultivars ‘Qiuyan’and‘Huili Qingpi Ruanzi’and identification of suspected male parent. The results showed that a total of 76 alleles were amplified from 22 pairs of SSR primers in the 168 cultivar samples,including 58 polymorphic loci(accounting for 76.3%). The average number of alleles per locus(Na),effective number of alleles(Ne),observed heterozygosity(Ho)and expected heterozygosity(He)was 3.455,2.269,0.362 and 0.538,respectively. The average Shannon’s information index(I)was 0.897,the polymorphism information content(PIC)of each marker ranged from 0.330 to 0.692,with an average of 0.462. 166 pomegranate cultivar samples were distinguished by the 22 pairs of SSR primers. However,‘Damantianhongtian’and‘Xiaomantianhongtian’were not effectively distinguished,which might be synonymous. Using the allelic information,a database containing the specific fingerprint code and two-dimensional fingerprint code for each cultivar was constructed. One true hybrid Q-1 was screened from 30 offspring of open-pollinated‘Qiuyan’by using the fingerprint information. Its suspected male parent is‘Yicheng Fengchan Maya’,with the LOD value of 5.96. Six true hybrids,H-4,H-49,H-51,H-87,H-94 and H-103,were screened from 118 offspring of open-pollinated‘Huili Qingpi Ruanzi’. Their suspected male parents were‘Sichuan Huangpisuan’‘Tunisian Ruanzi’‘Mengzi Honghua Baipi’‘Sichuan Huangpisuan’‘Tunisian Ruanzi’and‘Mengzi Honghua Baipi’,respectively.
The fungal pathogen Fusarium oxysporum f. sp. cubense(Foc)is an important soil-borne pathogenic fungus which causes Banana Fusarium wilt. The Foc race 4(Foc 4)attacking almost all Cavendish cultivars is currently noteworthy in global banana production. In order to explore the function of DCL-like genes in Foc4,the gene-knockout mutants ΔFocDCL1,ΔFocDCL2 and ΔFocDCL1/2 were obtained by homologous recombination technique. The phenotype analysis showed the mutants showed no significant differences on vegetative growth but significant reduced in conidia production compared to the Foc4. The ΔFocDCL2 mutant increased sensitive to Congo red,and the mutant significantly reduced the size of the colony and increased the number of aerial hyphae after Congo red treatment. Next,the pathogenicity test showed that virulence of ΔFocDCL2 and ΔFocDCL1/2 were significantly reduced compared with Foc4,respectively. Furthermore,miRNA deep sequencing data showed the length distribution of the total reads,and the frequency of the 5′ first nucleotide bias of the mutants were markedly changed compared with Foc4,respectively. The miRNA could be generated depending on individual,alternative or joint DCL manners,indicating the FocDCL with overlapped and redundant function in small RNA biogenesis. In addition,DCLs-independent miRNA also be identified in the sequencing data. These results indicated that FocDCL function involved in the stress response,conidia,pathogenicity and generation of miRNAs in Foc4.
The basic helix-loop-helix(bHLH)transcription factor family of strawberry was analyzed,and the transcription factor FvbHLH130 was identified in Fragaria vesca. qRT-PCR analysis in different tissues showed that FvbHLH130 was flower-specifically expressed. Overexpression of FvbHLH130 in Arabidopsis thaliana activated flowering in transgenic lines. The full-length coding sequence of FvbHLH130 was 960 bp,encoding a 319-amino-acid protein. The prediction of conserved domain of FvbHLH130 showed that 247-297 amino acids were bHLH binding domain. The promoter of FvbHLH130 contained hormone,stress- and low temperature-response elements,which indicated FvbHLH130 might be induced by biotic and abiotic stress. The amino acids sequence of FvbHLH130 revealed up to 93.70% similarity with RcbHLH130. FvbHLH130 sequence was more closely related to Rosaceae bHLH proteins and was homologous to AtFBH4. Agrobacterium-mediated transformation of Arabidopsis thaliana showed that the FvbHLH130 overexpression lines flowered seven days earlier than the control plants,and activated the expression of flowering-related genes AtAP1,AtFT,AtFUL and AtCO. The yeast two-hybrid results showed that FvbHLH130 interacted with FvARF4 and FvARF6,which may form protein complexes in the regulation of flowering.
In this study,200 KASP-SNP markers previously developed from Brassica rapa were estimated using 89 Chinese flowering cabbage varieties. The results showed that 131 of tested markers were successful in the genotyping,with conversion rate 65.50%,deletion rate 0.06,minor allele frequency(MAF)0.21,observed heterozygosity 0.27 and polymorphism information content(PIC)0.21. These markers were used for phylogenetic tree construction and genetic structure analysis. Further,they were screened based on the criteria-minor allele frequency > 0.25,polymorphism information content > 0.35,deletion rate < 0.03,and heterozygosity rate < 0.6 and 18 of them were selected as core KASP-SNP markers. Using these 18 markers,a fingerprinting for the 89 Chinese flowering cabbage varieties was constructed,demonstrating the feasibility of KASP technique in identification of Chinese flowering cabbage varieties.
Xanthomonas campestris pv. campestris(Xcc)is the causal agent of black rot of Brassicaceae crops. The cabbage protein BobHLH34 was found to be interacted with the effector XopR through the yeast two-hybrid system. The CDS of BobHLH34 was 996 bp encoding peptides with 331 amino acids. It has a conserved domain(basic/helix1-loop-helix2). Phylogenetic tree analysis showed that bHLH34 proteins from Brassica cretica had the highest homology with BobHLH34 protein. The subcellular localization results showed that BobHLH34 was located in the nucleus. The qRT-PCR results showed that the expression of BobHLH34 was increased significantly after Xcc inoculation of cabbage leaves. The expression reached the peak at 16 h,which was 7.7 times that of the control. Vacuum infiltration of cabbage seedlings with the BobHLH34-PCVA/PCVB vector effectively down-regulated the expression of BobHLH34 gene,which resulted in susceptibility to Xcc. Taken together,BobHLH34 could positively regulate cabbage defense to black rot.
The regular patterns of volatile composition and relative content were analyzed with dynamic headspace bagging-adsorption and GC-MS technology in‘High Noon’of tree peony cultivar. The results showed that 34 compounds were detected and the sequences of the total relative content of the volatiles in different flowering periods was as follows:full blooming > initial flowering > decay period > blooming stage,and the highest relative content was in petals. The change during one day showed an increasing firstly and then a decrease,and reached the peak between 14:00—16:00. The linalool,2,6-Octadiene-1-diol-3,7-dimethyl,germacrene D were the main floral ingredients in the volatile of tree peony cultivar‘High Noon’. In addition, the gene Germacrene D synthase(PsGDS,GenBank accession No. MZ513465)was cloned and identified from tree peony cultivar‘High Noon’. The open reading frame of PsGDS is 1 725 bp,encoding 574 amino acids. The sequence similarity analysis between PsGDS and GDS of other species showed that the sequence similarity reached 52.6% on average,and phylogenetic analysis revealed that PsGDS has a close evolutionary relationship with woody plants,among which,grapes is the closest,and herbs is farther. The expression level in‘High Noon’is higher than other peony varieties,and the expression pattern of PsGDS showed the PsGDS was expressed the highest at the initial flowering stage of different flowering period,was also the highest at the petals of different flowering periods,and at the time period from 12:00 to 14:00 during one day. The expression pattern of PsGDS was consistent with GDS,showing a very significant positive correlation. Additionally,the analysis of subcellular localization of PsGDS revealed that PsGDS was mainly localized in the cytoplasm. These results indicated that the PsGDS was the key gene to control the volatilization of germacrene D in‘High Noon’,and play a catalytic role in the cytoplasm to catalyze the production of germacrene D.
With diploid and tetraploid Hedychium coronarium as test material,the developmental process of cut flowers were observed. Micrographic changes of the flower stem base,corolla tube and petals were identified by scanning and transmission electron microscopy. With the bent neck of corolla tube and initial wilting of petal as markers,the developmental process of florets was divided into six stages:bracts cracking stage,initial opening stage,blooming stage,neck bending stage,initial wilting stage,and wilting stage. Neck bending of the floret corolla tube preceded petal wilting,and the senescence of corolla tube cells arose earlier than the petal cells. The diameter of the corolla tube of the tetraploid was extremely significantly more than that of the diploid,and the ratio of the corolla tube length out of bracts to the total length of the tetraploid was significantly less than that of the diploid. During the whole vase life,the cut flowers of tetraploid were in the state of net water absorption for longer time and the basal vessel of cut flower stem were blocked more slightly than those of the diploid. The neck bending of the tetraploid floret arose later than that of the diploid,and damages of mitochondria of corolla tube and petal cells were posterior to those of the diploid. In total,neck bending of the corolla tube was the landmark for the beginning of senescence of H. coronarium floret. The significant longer longevity of the tetraploid cut flowers may be due to the thicker corolla tube and stronger support from bracts to florets,the postponed senescence of corolla tube and petal cells,and stronger water absorption and anti-blocking ability of the flower stems.
To characterize the function of CpLEA,a group three LEA protein gene of Chimonanthus praecox(wintersweet),CpLEA is transformed into Escherichia coli and Arabidopsis thaliana. Compared with the control strain,transgenic E. coli showed higher tolerance to low-temperature. In vitro,purified CpLEA protein could protect lactate dehydrogenase(LDH)from inactivation. Overexpression of the CpLEA gene in Arabidopsis also improved the resistance of transgenic Arabidopsis to cold and drought stresses and the degree of improved resistance was positively correlated with the accumulation of gene overexpression. The expression characteristics of CpLEA gene were further analyzed by qRT-PCR in wintersweet cutflower branch during flower-bud and display-petal stage respectively under 4 ℃ low-temperature treatment. CpLEA gene expression was found to gradually increase after low-temperature treatment in cutflower branch at flower-bud stage,reaching a peak at 48 h of treatment,which was about 28 times higher than expression of the untreated group,and then the expression decreased,but was still higher than the untreated group. The expression of CpLEA gradually increased with the extension of low-temperature treatment time in cutflower branch at display-petal stage,then reached the highest level at 72 h,which was nine times as much as the untreated group. The expression of CpLEA in cutflowers remained basically constant at room temperature,while the low-temperature treatment induced a different degree of expression increase of CpLEA in the early stage of flower development. These results indicated that the CpLEA would play a protective role in plant cells under low-temperature stress,especially in early stage of flower development.
The Chinses orchid‘Longchangsu’and its leaf color mutant‘Yeyi Longchangsu’are excellent materials to study the formation mechanism of the leaf color of orchid. Differentially expressed genes(DEGs)in the leaves of‘Longchangsu’and‘Yeyi Longchangsu’were identifed by next-generation sequencing using Illumina Hiseq2500. Through the analysis of different expression genes,it was found that the genes related to pigment synthesis and chloroplast development might be the cause of the differences between‘Longchangsu’and‘Yeyi Longchangsu’.
Members of the AP2 subfamily were identified at the whole genome level in Chimonanthus praecox,and their expression patterns during flower development were analyzed. The expression profile of CpAP2-L11 was investigated,and 35S::CpAP2-L11 was introduced into Arabidopsis thaliana Columbia-0(Col-0)to analyze its function. A total of 20 AP2 subfamily transcription factors were identified,including five,six,and nine members from the euAP2,basalANT,and euANT groups,respectively,and all members of the euAP2 group have no miR172 binding sites. Synteny analysis revealed that 12 members form 16 pairs of duplicated genes,which were subject to purifying selection during the evolutionary process. Most AP2 subfamily members are highly expressed in April and May flower buds(FBs),with low expression during the entire or later stage of the chilling requirement(CR)accumulation;the expression level of CpAP2-L11 increased significantly in FBs initiating blooming when CR accumulation reached 570 CU. qRT-PCR analysis indicated CpAP2-L11 was highly expressed in the young fruit,outer tepals,and stamens,but a low expression level was detected in stems and leaves in C. praecox. The expression level of CpAP2-L11 was downregulated by high- or low-temperature. Ectopic expression of CpAP2-L11 in Arabidopsis showed earlier bolting time and the relative expression of FT,SOC1,LFY and AP1 genes increased significantly. CpAP2-L11 probably participates in chilling-induced dormancy breaking and blooming in winter and FBs differentiation in spring in C. praecox,also promoting flowering in ectopic overexpression Arabidopsis.
GRAS is a plant-specific transcription factor. In this study,78 GRAS genes were identified from the whole genome of apple(Malus × domestica)based on the conserved domain PF0351. MdGRASs encoding proteins belong to 11 subfamilies and most of them are the members of LISCL subfamily. They are located on 18 chromosomes,11 of which are located on chromosome 3. There were segmental duplication and tandem duplication events in GRAS family of apple. Ogran-specific expression profile analysis showed that,except for MdGRAS47,most of MdGRASs exhibited low transcript abundance levels in apple roots;MdGRAS20 showed higher expression level in shoots while MdGRAS18,MdGRAS55 and MdGRAS61 highly expressed in seeds. Promoter analysis indicated that all 78 MdGRASs contained light response elements,76 out of 78 MdGRASs contained stress-related elements and 37 out of 78 MdGRASs contained auxin response elements. It was confirmed that 17 MdGRASs could respond to 2,4-D with MdGRAS30 and MdGRAS61 responded to 2,4-D most significantly.
A new emerging banana leaf spot disease was found during a disease survey in the banana-producing area of Maoming City,Guangdong Province. The pathogen was isolated and tested for pathogenicity according to Koch's postulate,and the pathogen was identified based on morphological characteristics and sequence analyses of ITS,β-tubulin and tef1 genes. The results showed that strain MM3-2z9 could infect banana leaves and induce similar symptoms as in the field. The colony of strain MM3-2z9 on the PDA medium was white,producing obvious concentric ring patterns. The conidia were fusoid with 4-septate,three median cells versicoloured,apical cell hyaline,pyramidal,with two to four filiform apical appendages(mostly three),and basal cell with appendage single was centric and hyaline. Sequence homology analysis indicated that the ITS,β-tubulin and tef1 sequences of three single-conidial strains of MM3-2z9 were more than 98% identical to the corresponding sequences of Neopestalotiopsis musae stains. The phylogenetic tree constructed by the three fragments showed that strain MM3-2z9 was most closely related to N. musae. Therefore,strain MM3-2z9 was identified as N. musae based on morphological analysis and phylogenetic tree analysis. In addition to damaging banana(Musa AAA Cavendish)leaves,the pathogen could also quickly infect the leaves of M. × paradisiaca ABB and Musa ABB Pisang Awak‘Fenza 1’.
In the present study,709 inbred lines and backbone parents in cauliflower were resequenced,and their agronomic traits were analyzed. A core collection set containing 153 cauliflower lines was constructed based on the data of genotypes and 22 phenotypes. Furthermore,according to the data of phenotypic variation in these core collection,the results indicated that the percentage of mean difference was zero,the range coincidence rate was higher than 80%,and the variation rate of coefficient of variation was also commomly high. In addition,the analysis,such as phenotypic retention ratio,t test of phenotypic diversity index,t test of mean value of different traits,principal component and statistics of InDel locus counting and distribution,was carried out between the core collection and those original collection. The results confirmed that the core collection population largely represents the phenotypic and genetic diversity of the whole resource,which meets the requirements of core collection construction.
In order to explore the application prospect of matrine in the prevention and treatment of tea disease,the antifungal activity of matrine on five different Colletotrichum species including C. fioriniae,C. gloeosporioides,C. chongqingense,C. karstii and C. camelliae has been determined in this study. The results showed that matrine had significant inhibitory activity against five different Colletotrichum species. EC50(concentration for 50% of maximal effect)of the five Colletotrichum species were 5.856,6.557,3.038,7.963 and 4.397 mg · mL-1,and the antifungal activity of different species are significantly different. At low concentrations(1-8 mg · mL-1),matrine has a better control effect on both C. chongqingense and C. camelliae. With the increase of the concentration,the inhibitory rates of the five Colletotrichum species were all above 95% at 22 mg · mL-1. Microscopic examination showed that matrine had a significant effect on the mycelial and conidial growth of five Colletotrichum species. With the increase of matrine concentration,part of hyphae expanded irregularly,the number of conidia decreased and the conidia grew abnormally. Results of the biological activity of Colletotrichum species showed that the cell structure were destroyed,the cell permeability increased,and the cell oxidative stress response enhanced. The results of this study confirmed the antifungal activity of matrine against Colletotrichum species,and preliminarily revealed its antimicrobial mechanism by damaging cell membrane,which provided a theoretical basis for the prevention and control of tea brown blight disease caused by Colletotrichum.
The core of cutting is to induce adventitious roots in explants,among which juvenile and auxin are the main limiting factors affecting adventitious roots. This review focuses on the effects of auxin synthesis,transport and signal transduction,as well as the mechanism of juvenile on adventitious root development,the current understanding of the molecular mechanisms by how juvenile and auxin cooperatively regulate the rooting of cuttings in plants were summarize.
‘Yongzha 805’is a new tuber mustard cultivar developed by systematic selection from,HZ07 × NZ07. It is a new suitable for mechanized harvesting. The plant is erect with broad-leaf type. The full growth period is 170 d. It is 1.5 cm far-surface base. The tuberous stem is of cylinder shape. The tuberous stem diameter is 9-12 cm. The longitudinal diameter is 11-13 cm. The average fresh weight is 420 g. The processing quality is better. It is resistant to TuMV and downy mildew. It is tolerant to clubroot. The cultivar was suitable for planted in Zhejiang Province.
Panus giganteus‘Shenxun 1’was artificially domesticated by wild germplasm which was gathered from Nanjing County,Zhangzhou City,Fujian Province in 2014. The cultivar is characterized by fast growth rate,white and strong of the mycelium,easy to form primordium and high temperature resistance. The fruiting-body is moderate and small size,the cap color is light brown,the yield is high and the quality is good. The cultivar is suitable for facility scale cultivation.
‘Longsheng Jiali’watermelon is a new sweet king variety hybrid with high quality and high resistance to Fusarium wilt,which was bred by crossing inbred line S71385 × K10197FR. The fruit is elliptical,with dark green peel and dark green toothed strip. The peel is 1.0 cm thick and has good toughness. The flesh is red,firming,with 12.1% soluble solids content in the center. The single fruit weight is 10.0-12.0 kg. The whole growth period is 95 d,and the fruit development period is 33 d. It has high resistance to Fusarium wilt and anthracnose. The yield is 60 867.0 kg · hm-2. It is suitable for open cultivation in northeast area.
Based on 11 years of introduction and trial planting,resource evaluation,and hybrid breeding,selected herbaceous peonies‘Fluttering Pink’‘Fairy’s Cheek’‘Blushing Smile’ and‘Tiny Lotus’from the many progenies of directional hybridization. Fluttering Pink and Fairy's Cheek belong to the Lactiflora group,with double flowers,stout stems and 80-90 cm plant height,which are suitable for cultivation as cut flowers. Blushing Smile and Tiny Lotus belong to hybrid group,with triploid,early flowering,single flower,peculiar leaf shape and full plant type,so they are suitable for garden ornamental cultivation.