Time filter

Source Type

Qi Y.,Northwest University, China | Qi Y.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Lou Q.,Northwest University, China | Lou Q.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | And 6 more authors.
Plant Cell, Tissue and Organ Culture | Year: 2013

Flavonoid 3′, 5′-hydoxylase (F3′5′H) is a key enzyme for biosynthesis of the blue anthocyanin pigment delphinidin. A number of F3′5′H genes from dicots have been tested for their effects on flower pigmentation; here F3′5′H from a monocot was tested for its effect on delphinidin accumulation in petals. To this end, F3′5′H (PhF3′5′H) from the orchid Phalaenopsis was expressed under the control of the chalcone synthase promoter in petunia flowers. Quantitative RT-PCR showed that PhF3′5′H was expressed mainly in the petal limb; this expression produced an increase in dihydromyricetin and delphinidin and a change in petal color from pink to deeper pink. To increase the accumulation of delphinidin, Hyacinth HyDFR, which encodes dihydroflavonol 4-reductase, and petunia DifF, which encodes a cytochrome b 5 that is required for full activity of F3′5′H were overexpressed. The HyDFR petunia transformants had a deeper color petal limb, increased dihydromyricetin and delphinidin contents and adaxial petals with a number of blue cells. The flowers of the DifF petunia transformants also showed a slight color change. We also tested PhF3′5′H in Lilium oriental 'Sorbonne', where transient PhF3′5′H expression by particle bombardment resulted in purple cells in the petals. Production of blue flowers by Phalaenopsis F3′5′H and hyacinth DFR potentially enables manipulation of flower color in ornamental plants, including production of blue flowers. © 2013 Springer Science+Business Media Dordrecht.


Qi Y.,Northwest University, China | Qi Y.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Lou Q.,Northwest University, China | Lou Q.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | And 8 more authors.
Protoplasma | Year: 2013

The inflorescence of the broad-leafed grape hyacinth, Muscari latifolium, shows an interesting, two-tone appearance with the upper flowers being pale blue and the lower ones purple. To elucidate the mechanism of the differential color development, anatomical research was carried out and a cytological study of the colored protoplasts in which the shapes of the cells accumulating anthocyanin were observed by scanning electron microscopy. Next, vacuolar pH was recorded using a pH meter with a micro combination pH electrode, and the sap's metal-ion content was measured by inductively coupled plasma mass spectrometry. The anthocyanin and co-pigment composition was determined by high-performance liquid chromatography (HPLC). Chemical analyses reveal that the difference in metal-ion content of the two parts was not great. The vacuolar pHs of the upper and lower flowers were 5.91 and 5.84, respectively, with the difference being nonsignificant. HPLC results indicate that the dihydroflavonol and flavonol contents are also very similar in the two sorts of flower. However, the upper flowers contained only delphinidin, whereas the lower flowers also contained cyanidin. The total anthocyanin content in the lower flowers was 4.36 mg g-1, which is approximately seven times higher than in the upper flowers, while the delphinidin content is four times higher. Quantitative real-time PCR analysis established that the two-tone flower was a result of different expressions of the F3′5′H, F3′H and DFR genes, and these lead to different amounts of anthocyanin. © 2013 Springer-Verlag Wien.


He M.,Northwest University, China | He M.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Xu Y.,Northwest University, China | Xu Y.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | And 16 more authors.
Protoplasma | Year: 2013

Downy mildew, caused by the oomycete Plasmopara viticola, is a serious fungal disease in the cultivated European grapevines (Vitis vinifera L.). The class 10 of pathogenesis-related (PR) genes in grapevine leaves was reported to be accumulated at mRNA level in response to P. viticola infection. To elucidate the functional roles of PR10 genes during plant-pathogen interactions, a PR10 gene from a fungal-resistant accession of Chinese wild Vitis pseudoreticulata (designated VpPR10. 2) was isolated and showed high homology to PR10. 2 from susceptible V. vinifera (designated VvPR10. 2). Comparative analysis displayed that there were significant differences in the patterns of gene expression between the PR10 genes from the two host species. VpPR10. 2 was induced with high level in leaves infected by P. viticola, while VvPR10. 2 showed a low response to this inoculation. Recombinant VpPR10. 2 protein showed DNase activity against host genomic DNA and RNase activity against yeast total RNA in vitro. Meanwhile, recombinant VpPR10. 2 protein inhibited the growth of tobacco fungus Alternaria alternata and over-expression of VpPR10. 2 in susceptible V. vinifera enhanced the host resistance to P. viticola. The results from subcellular localization analysis showed that VpPR10. 2 proteins were distributed dynamically inside or outside of host cell. Moreover, they were found in haustorium of P. viticola and nucleus of host cell which was associated with a nucleus collapse at 10 days post-inoculation. Taken together, these results suggested that VpPR10. 2 might play an important role in host plant defense against P. viticola infection. © 2012 Springer-Verlag.


Peng S.,Northwest University, China | Peng S.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Zhu Z.,Northwest University, China | Zhu Z.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | And 10 more authors.
Plant Molecular Biology Reporter | Year: 2013

Heat shock transcription factors (Hsfs) play a central role in the environmental stress response of many plant species, but their functions are poorly understood in grapevine. In this study, an Hsf, designated as VpHsf1 (GenBank accession no. GU393313), was isolated from Chinese wild Vitis pseudoreticulata for the first time. Its full-length cDNA is 1,428 bp, encoding an Hsf protein of 306 amino acids with a calculated molecular mass of 33. 96 kDa. Multiple sequence alignment and phylogenetic analyses showed that VpHsf1 was a novel member of the Hsf class B2 family. Nuclear localization of the protein encoded by VpHsf1 was detected in onion epidermal cells. VpHsf1 expression was induced by heat and drought, as well as by the pathogen Erysiphe necator. VpHsf1 overexpression in tobacco reduced the plant's basal thermotolerance, increased its acquired thermotolerance, and enhanced its susceptibility to osmotic stress and pathogen Phytophthora parasitica var. nicotianae Tucker. Taken together, the results indicate that grapevine VpHsf1 is involved in response to biotic and abiotic stresses. © 2012 Springer-Verlag.


Zhu Z.,Northwest University, China | Zhu Z.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Shi J.,Northwest University, China | Shi J.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | And 6 more authors.
Plant Cell Reports | Year: 2012

Chinese wild grapevine Vitis pseudoreticulata accession 'Baihe-35-1' is identified as the precious resource with multiple resistances to pathogens. A directional cDNA library was constructed from the young leaves inoculated with Erysiphe necator. A total of 3,500 clones were sequenced, yielding 1,727 unigenes. Among them, 762 unigenes were annotated and classified into three classes, respectively, using Gene Ontology, including 22 ESTs related to transcription regulator activity. A novel WRKY transcription factor was isolated from the library, and designated as VpWRKY3 (GenBank Accession No. JF500755). The full-length cDNA is 1,280 bp, encoding a WRKY protein of 320 amino acids. VpWRKY3 is localized to nucleus and functions as a transcriptional activator. QRT-PCR analysis showed that the VpWRKY3 specifically accumulated in response to pathogen, salicylic acid, ethylene and drought stress. Overexpression of VpWRKY3 in tobacco increased the resistance to Ralstonia solanacearum, indicating that VpWRKY3 participates in defense response. Furthermore, VpWRKY3 is also involved in abscisic acid signal pathway and salt stress. This experiment provided an important basis for understanding the defense mechanisms mediated by WRKY genes in China wild grapevine. Generation of the EST collection from the cDNA library provided valuable information for the grapevine breeding. Key message We constructed a cDNA library from Chinese wild grapevine leaves inoculated with powdery mildew. VpWRKY3 was isolated and demonstrated that it was involved in biotic and abiotic stress responses. © 2012 Springer-Verlag.


Yu Y.,Northwest University, China | Yu Y.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Xu W.,Northwest University, China | Xu W.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | And 12 more authors.
Planta | Year: 2013

RING-finger proteins (RFP) function as ubiquitin ligases and play key roles in plant responses to biotic and abiotic stresses. However, little information is available on the regulation of RFP expression. Here, we isolate and characterize the RFP promoter sequence from the disease-resistant Chinese wild grape Vitis pseudoreticulata accession Baihe-35-1. Promoter-GUS fusion assays revealed that defense signaling molecules, powdery mildew infection, and heat stress induce VpRFP1 promoter activity. By contrast, the RFP1 promoter isolated from Vitis vinifera was only slightly induced by pathogen infection and heat treatment. By promoter deletion analysis, we found that the -148 bp region of the VpRFP1 promoter was the core functional promoter region. We also found that, in Arabidopsis, VpRFP1 expressed under its own promoter activated defense-related gene expression and improved disease resistance, but the same construct using the VvRFP1 promoter slightly improve disease resistance. Our results demonstrated that the -148 bp region of the VpRFP1 promoter plays a key role in response to pathogen and heat stress, and suggested that expression differences between VpRFP1 and VvRFP1 may be key for the differing disease resistance phenotypes of the two Vitis genotypes. © 2012 Springer-Verlag.


Zhu Z.,Northwest University, China | Zhu Z.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Shi J.,Northwest University, China | Shi J.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | And 6 more authors.
Biotechnology Letters | Year: 2012

NAC (for NAM, ATAF1, 2, and CUC2) family genes encode plant-specific transcription factors that play important roles in plant development regulation and in abiotic and biotic stresses. However, the function of NAC genes in grapevines is not clear. A novel NAC transcription factor, designated as VpNAC1, was isolated from Chinese wild Vitis pseudoreticulata. It belongs to the TERN subgroup and is a nuclear-targeting protein and functions as a transcriptional activator. Moreover, VpNAC1 was induced by the fungus Erysiphe necator and the exogenous hormones, particularly salicylic acid, methyl jasmonate and ethylene. Over-expression of VpNAC1 in tobacco plants enhanced their resistance to Erysiphe cichoracearum and Phytophthora parasitica var. nicotianae Tucker. These results suggest that VpNAC1 acts as a positive regulator in biotic stresses. © 2012 Springer Science+Business Media B.V.


Lou Q.,Northwest University, China | Lou Q.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Liu Y.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region | Liu Y.,Northwest University, China | And 10 more authors.
Journal of Experimental Botany | Year: 2014

Grape hyacinth (Muscari) is an important ornamental bulbous plant with an extraordinary blue colour. Muscari armeniacum, whose flowers can be naturally white, provides an opportunity to unravel the complex metabolic networks underlying certain biochemical traits, especially colour. A blue flower cDNA library of M. armeniacum and a white flower library of M. armeniacum f. album were used for transcriptome sequencing. A total of 89 926 uni-transcripts were isolated, 143 of which could be identified as putative homologues of colour-related genes in other species. Based on a comprehensive analysis relating colour compounds to gene expression profiles, the mechanism of colour biosynthesis was studied in M. armeniacum. Furthermore, a new hypothesis explaining the lack of colour phenotype of the grape hyacinth flower is proposed. Alteration of the substrate competition between flavonol synthase (FLS) and dihydroflavonol 4-reductase (DFR) may lead to elimination of blue pigmentation while the multishunt from the limited flux in the cyanidin (Cy) synthesis pathway seems to be the most likely reason for the colour change in the white flowers of M. armeniacum. Moreover, mass sequence data obtained by the deep sequencing of M. armeniacum and its white variant provided a platform for future function and molecular biological research on M. armeniacum. © The Author 2014.

Loading Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region collaborators
Loading Key Laboratory of Biology and Genetic Improvement of Horticultural Crops Northwest Region collaborators