Plant argonautes (AGOs) play important roles in the defense responses against viruses. The expression of Nicotiana benthamiana AGO5 gene (NbAGO5) is highly induced by Bamboo mosaic virus (BaMV) infection; however, the underlying... more
Plant argonautes (AGOs) play important roles in the defense responses against viruses. The expression of Nicotiana benthamiana AGO5 gene (NbAGO5) is highly induced by Bamboo mosaic virus (BaMV) infection; however, the underlying mechanisms remain elusive. In this study, we have analyzed the potential promoter activities of NbAGO5 and its interactions with viral proteins by using a 2,000 bp fragment, designated as PN1, upstream to the translation initiation of NbAGO5. PN1 and seven serial 5′-deletion mutants (PN2–PN8) were fused with a β-glucuronidase (GUS) reporter and introduced into the N. benthamiana genome by Agrobacterium-mediated transformation for further characterization. It was found that PN4-GUS transgenic plants were able to drive strong GUS expression in the whole plant. In the virus infection tests, the GUS activity was strongly induced in PN4-GUS transgenic plants after being challenged with potexviruses. Infiltration of the transgenic plants individually with BaMV coa...
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Wolfberry Lycium, an economically important genus of the Solanaceae family, contains approximately 80 species and shows a fragmented distribution pattern among the Northern and Southern Hemispheres. Although several herbaceous species of... more
Wolfberry Lycium, an economically important genus of the Solanaceae family, contains approximately 80 species and shows a fragmented distribution pattern among the Northern and Southern Hemispheres. Although several herbaceous species of Solanaceae have been subjected to genome sequencing, thus far, no genome sequences of woody representatives have been available. Here, we sequenced the genomes of 13 perennial woody species of Lycium, with a focus on Lycium barbarum. Integration with other genomes provides clear evidence supporting a whole-genome triplication (WGT) event shared by all hitherto sequenced solanaceous plants, which occurred shortly after the divergence of Solanaceae and Convolvulaceae. We identified new gene families and gene family expansions and contractions that first appeared in Solanaceae. Based on the identification of self-incompatibility related-gene families, we inferred that hybridization hotspots are enriched for genes that might be functioning in gametophyt...
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Phosphorus (P) is a macronutrient essential for plant growth and development. However, the solubility of inorganic phosphate (Pi), the available form for plant uptake, in soils is low. Plants have evolved various adaptive mechanisms to... more
Phosphorus (P) is a macronutrient essential for plant growth and development. However, the solubility of inorganic phosphate (Pi), the available form for plant uptake, in soils is low. Plants have evolved various adaptive mechanisms to cope with Pi deficiency stress. Change of root system architecture (RSA) is a well-known adaption in response to Pi deficiency for exploration of available Pi at top soil layers. Although aux in has long been considered to be the key player controlling RSA under Pi deficiency, increasing evidences indicate ethylene also plays an important role in regulating these processes. In addition to RSA, it has been reported in recent years that ethylene is involved in the regulation of other Pi starvation responses (PSRs) including Pi transporter gene expression, acid phosphatase activity and anthocyan in accumulation. It reveals that ethylene may regulate a complex network for plant adaptive responses to Pi deficiency. Here, we review the current knowledge on ...
Avian reoviruses (ARVs) are important pathogens that cause considerable economic losses in poultry farming. To date, host factors that control stabilization of ARV proteins remain largely unknown. In this work we determined that the... more
Avian reoviruses (ARVs) are important pathogens that cause considerable economic losses in poultry farming. To date, host factors that control stabilization of ARV proteins remain largely unknown. In this work we determined that the eukaryotic chaperonin T-complex protein-1 (TCP-1) ring complex (TRiC) is essential for avian reovirus (ARV) replication by stabilizing outer-capsid protein σC, inner core protein σA, and the non-structural protein σNS of ARV. TriC serves as a chaperone of viral proteins and prevent their degradation via the ubiquitin-proteasome pathway. Furthermore, reciprocal co-immunoprecipitation assays confirmed the association of viral proteins (σA, σC, and σNS) with TRiC. Immunofluorescence staining indicated that the TRiC chaperonins (CCT2 and CCT5) are colocalized with viral proteins σC, σA, and σNS of ARV. In this study, inhibition of TRiC chaperonins (CCT2 and CCT5) by the inhibitor HSF1A or shRNAs significantly reduced expression levels of the σC, σA, and σNS proteins of ARV as well as virus yield, suggesting that the TRiC complex functions in stabilization of viral proteins and virus replication. This study provides novel insights into TRiC chaperonin governing virus replication via stabilization of outer-capsid protein σC, inner core protein σA, and the non-structural protein σNS of ARV.
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Orchid gynostemium, the fused organ of the androecium and gynoecium, and ovule development are unique developmental processes. Two DROOPING LEAF/CRABS CLAW (DL/CRC) genes, PeDL1 and PeDL2, were identified from the Phalaenopsis orchid... more
Orchid gynostemium, the fused organ of the androecium and gynoecium, and ovule development are unique developmental processes. Two DROOPING LEAF/CRABS CLAW (DL/CRC) genes, PeDL1 and PeDL2, were identified from the Phalaenopsis orchid genome and functionally characterized. Phylogenetic analysis indicated that the most recent common ancestor of orchids contained the duplicated DL/CRC-like genes. Temporal and spatial expression analysis indicated that PeDL genes are specifically expressed in the gynostemium and at the early stages of ovule development. Both PeDLs could partially complement an Arabidopsis crc-1 mutant. Virus-induced gene silencing (VIGS) of PeDL1 and PeDL2 affected the number of protuberant ovule initials differentiated from the placenta. Transient overexpression of PeDL1 in Phalaenopsis orchids caused abnormal development of ovule and stigmatic cavity of gynostemium. PeDL1, but not PeDL2, could form a heterodimer with Phalaenopsis equestris CINCINNATA 8 (PeCIN8). Paral...
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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ABSTRACTThe orchid flower is renowned for complexity of flower organ morphogenesis and has attracted great interest from scientists. The YABBY genes encode plant-specific transcription factors with important roles in vegetative and... more
ABSTRACTThe orchid flower is renowned for complexity of flower organ morphogenesis and has attracted great interest from scientists. The YABBY genes encode plant-specific transcription factors with important roles in vegetative and reproductive development in seed plants.DROOPING LEAF/CRABS CLAW(DL/CRC) orthologs are involved in reproductive organ development (especially carpels) of angiosperms. Orchid gynostemium (the fused organ of the androecium and gynoecium) and ovule development are unique developmental processes. Understanding theDL/CRC-likegenes controlling the developmental program of the gynostemium and ovule could provide accessible information for reproductive organ molecular regulation in orchids. TwoDL/CRC-likegenes, namedPeDL1andPeDL2, were cloned fromPhalaenopsis equestris. The orchid DL/CRC forms a monophyletic clade with two subclades including AshDL, PeDL1 and DcaDL1 in subclade I, and PeDL2 and DcaDL2 in subclade II. The temporal and spatial expression analysis i...
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Mycorrhizas play an important role in plant growth and development. In mycorrhizal symbioses, fungi supply soil mineral nutrients, such as nitrogen and phosphorus, to their host plants in exchange for carbon resources. Plants gain as much... more
Mycorrhizas play an important role in plant growth and development. In mycorrhizal symbioses, fungi supply soil mineral nutrients, such as nitrogen and phosphorus, to their host plants in exchange for carbon resources. Plants gain as much as 80% of mineral nutrient requirements from mycorrhizal fungi, which form associations with the roots of over 90% of all plant species. Orchid seeds lack endosperms and contain very limited storage reserves. Therefore, the symbiosis with mycorrhizal fungi that form endomycorrhizas is essential for orchid seed germination and protocorm development under natural conditions. The rapid advancement of next-generation sequencing contributes to identifying the orchid and fungal genes involved in the orchid mycorrhizal symbiosis and unraveling the molecular mechanisms regulating the symbiosis. We aim to update and summarize the current understanding of the mechanisms on orchid-fungus symbiosis, and the main focus will be on the nutrient exchange between o...
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is a scented orchid emitting large amount of monoterpenes. GERANYL DIPHOSPHATE SYNTHASE (PbGDPS) is the key enzyme for monoterpene biosynthesis, and shows concomitant expression with the emission of monoterpenes during flower development... more
is a scented orchid emitting large amount of monoterpenes. GERANYL DIPHOSPHATE SYNTHASE (PbGDPS) is the key enzyme for monoterpene biosynthesis, and shows concomitant expression with the emission of monoterpenes during flower development in . Here, we identified a dual repeat -element in the promoter that is critical for monoterpene biosynthesis in orchids. A strong correlation between the dual repeat and the monoterpene production was revealed by examination of the promoter fragments over 12 species. Serial-deletion of the 2-kb promoter fragments demonstrated that the integrity of the dual repeat was crucial for its promoter activities. By screening the transcription factors (TFs) cDNA library using yeast one-hybrid assay, AtbZIP18, a member of group I of bZIP TFs, was identified to be able to bind the dual repeat. We then identified in the transcriptome of , showing 83% identity in the DNA binding region with that of AtbZIP18, and the expression level of was higher in the scented ...
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Constituting approximately 10% of flowering plant species, orchids (Orchidaceae) display unique flower morphologies, possess an extraordinary diversity in lifestyle, and have successfully colonized almost every habitat on Earth1,2,3. Here... more
Constituting approximately 10% of flowering plant species, orchids (Orchidaceae) display unique flower morphologies, possess an extraordinary diversity in lifestyle, and have successfully colonized almost every habitat on Earth1,2,3. Here we report the draft genome sequence of Apostasia shenzhenica4, a representative of one of two genera that form a sister lineage to the rest of the Orchidaceae, providing a reference for inferring the genome content and structure of the most recent common ancestor of all extant orchids and improving our understanding of their origins and evolution. In addition, we present transcriptome data for representatives of Vanilloideae, Cypripedioideae and Orchidoideae, and novel third-generation genome data for two species of Epidendroideae, covering all five orchid subfamilies. A. shenzhenica shows clear evidence of a whole-genome duplication, which is shared by all orchids and occurred shortly before their divergence. Comparisons between A. shenzhenica and...
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Regulation of the MAP kinase gene (OsMAPK2) expression in rice under metal, copper, stress conditions was investigated. OsMAPK2 transcript accumulation was enhanced by copper and H2O2 in rice root-tip cells. To investigate how the OsMAPK2... more
Regulation of the MAP kinase gene (OsMAPK2) expression in rice under metal, copper, stress conditions was investigated. OsMAPK2 transcript accumulation was enhanced by copper and H2O2 in rice root-tip cells. To investigate how the OsMAPK2 gene is regulated in response to copper, inhibitor studies were performed. Using Northern blot analysis, it was shown that antioxidant agent (GSH), calcium chelator (EGTA),
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Early signalling events that control the process of heavy metal-induced cell death are largely unknown in plants. In mammals protein tyrosine phosphorylation plays an important role in the activation of programmed cell death. We thus... more
Early signalling events that control the process of heavy metal-induced cell death are largely unknown in plants. In mammals protein tyrosine phosphorylation plays an important role in the activation of programmed cell death. We thus examined the involvement of tyrosine phosphorylation in Cu-induced rice cell death. This investigation demonstrates that Cu induces cell death and DNA fragmentation in rice root cells. In the presence of Cu, the level of phosphotyrosine accumulation declined in the band of 45 kDa, p45. To analyze the role of tyrosine dephosphorylation for the regulation of Cu-induced cell death more precisely, we increased levels of tyrosine phosphorylation using the protein tyrosine phosphatase inhibitor, sodium orthovanadate (Na(3)VO(4)). Treatment of rice roots with Na(3)VO(4) blocked Cu-induced cell death and protein tyrosine dephosphorylation. In addition, the antioxidant GSH and the calcium chelator EGTA significantly abolished Cu-induced cell death and protein tyrosine dephosphorylation. These results provide evidence that dephosphorylation of a tyrosine-phosphorylated protein, p45, is an important step in the Cu-triggered signalling transduction pathway.
Research Interests: Biology, Cell Biology, Medicine, Multidisciplinary, Copper, and 15 moreHeavy Metal, Cell Death, Plant Signal Transduction, Oryza Sativa, Phosphorylation, Programmed cell death, Plant Roots, Protein tyrosine phosphatase, Protein Tyrosine Phosphatases, PLANT PROTEINS, Tyrosine, Tyrosine Phosphorylation, Dephosphorylation, DNA fragmentation, and Vanadates
Plants have evolved mechanisms to improve utilization efficiency or acquisition of inorganic phosphate (Pi) in response to Pi deficiency, such as altering root architecture, secreting acid phosphatases, and activating the expression of... more
Plants have evolved mechanisms to improve utilization efficiency or acquisition of inorganic phosphate (Pi) in response to Pi deficiency, such as altering root architecture, secreting acid phosphatases, and activating the expression of genes related to Pi uptake and recycling. Although many genes responsive to Pi starvation have been identified, transcription factors that affect tolerance to Pi deficiency have not been well characterized. We show here that defect in the ELONGATED HYPOCOTYL 5 (HY5) transcription factor gene results in tolerance to Pi deficiency in Arabidopsis. The primary root length of hy5 was only slightly inhibited under Pi deficient condition and its fresh weight was significantly higher than that of wild type. The Pi deficiency-tolerant phenotype of hy5 was similarly observed when grown on the medium without Pi. In addition, a double mutant, hy5slr1, without lateral roots also showed tolerance to phosphate deficiency, indicating that the tolerance of hy5 does no...
Research Interests: Chemistry, Biology, Phosphatase, Arabidopsis, Transcription Factor, and 3 morePi, Phosphate, and Hypocotyl
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Research Interests: Plant Biology, Calcium, Mitochondria, Copper, Permeability, and 15 moreHeavy Metal, Experimental Botany, Plant growth, Kinase inhibitor, Oryza Sativa, Plant Roots, Cadmium, Mitogen Activated Protein Kinase, NADPH oxidase, Experimental, Calcium Binding Proteins, MAP Kinase, Oryza Sativa L, Hydroxyl Radical, and myelin basic protein
Regulation of the MAP kinase gene (OsMAPK2) expression in rice under metal, copper, stress conditions was investigated. OsMAPK2 transcript accumulation was enhanced by copper and H2O2 in rice root-tip cells. To investigate how the OsMAPK2... more
Regulation of the MAP kinase gene (OsMAPK2) expression in rice under metal, copper, stress conditions was investigated. OsMAPK2 transcript accumulation was enhanced by copper and H2O2 in rice root-tip cells. To investigate how the OsMAPK2 gene is regulated in response to copper, inhibitor studies were performed. Using Northern blot analysis, it was shown that antioxidant agent (GSH), calcium chelator (EGTA), plasma membrane calcium channel blocker (La3+) and protein phosphatase inhibitor (cantharidin) inhibited copper-induced OsMAPK2 gene activation. We suggest that the stimulation of OsMAPK2 transcript accumulation by copper in rice roots operates may through an intracellular signalling cascade mediated by reactive oxygen species, extracellular calcium ions and cantharidin-sensitive protein phosphatase(s).