（E）-β-Caryophyllene is a sesquiterpene compound widely distributed in plants and functions in plant defence. However, little is known about the sequence and function of （E）-β-caryophyllene synthase in lima bean ...（E）-β-Caryophyllene is a sesquiterpene compound widely distributed in plants and functions in plant defence. However, little is known about the sequence and function of （E）-β-caryophyllene synthase in lima bean （Phaseolus lunatus）. Here, we report a new full-length cDNA （PICAHS） encoding （E）-β-caryophyllene synthase, a possible key enzyme of plant defence. The cDNA of PICAHS contains an open reading frame of 1 761 bp, encoding a protein of 586 amino acids with a predicted mass of 67.95 kDa. The deduced amino acid sequence shows 52% identity with sesquiterpene synthase MtCAHS of Med- icago truncatula. Based on phylogenetic analysis, PICAHS is classified as the terpene synthases （TPS）-a subfamily. The recombinant enzyme, expressed in Escherichia coil, catalysed the formation of a major product （E）-β-caryophyllene （82%） and a minor product a-humulene （18%） from farnesyl dJphosphate. Real-time quantitative PCR （qRT-PCR） analysis found that the PICAHS transcript was significantly up-regulated in leaves after treatment with spider mites and alamethicin （ALA）, suggesting its ecological function in plant defence.展开更多
Paris polyphylla var. yunnanensis is an important medicinal plant with abundant saponins that are widely used in the pharmaceuticals industry. It is unclear why the levels of active ingredients increase as these plant...Paris polyphylla var. yunnanensis is an important medicinal plant with abundant saponins that are widely used in the pharmaceuticals industry. It is unclear why the levels of active ingredients increase as these plants age. We speculated that the concentrations of those components in the rhizomes are mediated by fungal endophytes. To test this hypothesis, we took both culture-dependent and-independent(metagenomics) approaches to analyze the communities of endophytic fungi that inhabit those rhizomes in plants of different age classes(four, six, and eight years old). In all, 147 isolates representing 18 fungal taxa were obtained from 270 segments(90 per age class). Based on morphological and genetic characteristics, Fusarium oxysporum(46.55% frequency of occurrence) was the predominant endophyte,followed by Leptodontidium sp.(8.66%) and Trichoderma viride(6.81%). Colonization of endophytic fungi was maximized in the eight-year-old rhizomes(33.33%) when compared with four-year-old(21.21%) and six-year-old(15.15%) rhizomes. Certain fungal species were present only at particular ages. For example,Alternaria sp., Cylindrocarpon sp., Chaetomium sp., Paraphaeosphaeria sporulosa, Pyrenochaeta sp., Penicillium swiecickii, T. viride, and Truncatella angustata were found only in the oldest plants. Analysis of(metagenomics) community DNA extracted from different-aged samples revealed that, at the class level,the majority of fungi had the highest sequence similarity to members of Sordariomycetes, followed by Eurotiomycetes and Saccharomycetes. These results were mostly in accord with those we obtained using culture methods. Fungal diversity and richness also changed over time. Our investigation is the first to show that the diversity of fungi in rhizomes of P. polyphylla var. yunnanensis is altered as plants age, and our findings provide a foundation for future examinations of useful compounds.展开更多
Olfaction is primarily mediated by highly specified olfactory receptors （ORs）. Here, we cloned and identified an olfactory receptor, named SlituOR1 （Genbank no. JN835269）, from Spodoptera litura and found evidence...Olfaction is primarily mediated by highly specified olfactory receptors （ORs）. Here, we cloned and identified an olfactory receptor, named SlituOR1 （Genbank no. JN835269）, from Spodoptera litura and found evidence that it is a candidate pheromone receptor. It exhibited male-biased expression in the antennae, where it was localized at the base of sensilla trichoidea, the antennal sensilla mainly responsive to pheromones in moths. Conserved orthologues of this receptor, found among known pheromone receptors within the Lepidoptera, and SlituOR1 were placed among a clade of candidate pheromone re- ceptors in a phylogeny tree of insect OR gene sequences. SlituOR1 showed differential expression in S. litura populations attracted to traps baited with different ratios of the two sex pheromone components （9Z,11E）-tetradecadienyl acetate （Z9E11-14：OAc） and （9Z,12E）-tetradecadienyl acetate （Z9E12-14：OAc）. Knocking down of SlituOR1 by RNA interference reduced the electroantennogram （EAG） response to Z9E11-14：OAc, and this result is consistent with the field trapping experiment. We infer that variation in transcrip- tion levels of olfactory receptors may modulate sex pheromone perception in male moths and could provide some of the flexibility required to maintain the functionality of com- munication with females when a population is adapting to a new niche and reproductive isolation becomes an advantage.展开更多
基金funded by the International Science and Technology Cooperation Program of China (2013DFG32230)the Major Project of Genetically Modified Organisms Breeding,China (2016ZX08010005)
文摘（E）-β-Caryophyllene is a sesquiterpene compound widely distributed in plants and functions in plant defence. However, little is known about the sequence and function of （E）-β-caryophyllene synthase in lima bean （Phaseolus lunatus）. Here, we report a new full-length cDNA （PICAHS） encoding （E）-β-caryophyllene synthase, a possible key enzyme of plant defence. The cDNA of PICAHS contains an open reading frame of 1 761 bp, encoding a protein of 586 amino acids with a predicted mass of 67.95 kDa. The deduced amino acid sequence shows 52% identity with sesquiterpene synthase MtCAHS of Med- icago truncatula. Based on phylogenetic analysis, PICAHS is classified as the terpene synthases （TPS）-a subfamily. The recombinant enzyme, expressed in Escherichia coil, catalysed the formation of a major product （E）-β-caryophyllene （82%） and a minor product a-humulene （18%） from farnesyl dJphosphate. Real-time quantitative PCR （qRT-PCR） analysis found that the PICAHS transcript was significantly up-regulated in leaves after treatment with spider mites and alamethicin （ALA）, suggesting its ecological function in plant defence.
基金supported by grants from the National Natural Science Foundation of China (81473310, 31260075, 31560085)
文摘Paris polyphylla var. yunnanensis is an important medicinal plant with abundant saponins that are widely used in the pharmaceuticals industry. It is unclear why the levels of active ingredients increase as these plants age. We speculated that the concentrations of those components in the rhizomes are mediated by fungal endophytes. To test this hypothesis, we took both culture-dependent and-independent(metagenomics) approaches to analyze the communities of endophytic fungi that inhabit those rhizomes in plants of different age classes(four, six, and eight years old). In all, 147 isolates representing 18 fungal taxa were obtained from 270 segments(90 per age class). Based on morphological and genetic characteristics, Fusarium oxysporum(46.55% frequency of occurrence) was the predominant endophyte,followed by Leptodontidium sp.(8.66%) and Trichoderma viride(6.81%). Colonization of endophytic fungi was maximized in the eight-year-old rhizomes(33.33%) when compared with four-year-old(21.21%) and six-year-old(15.15%) rhizomes. Certain fungal species were present only at particular ages. For example,Alternaria sp., Cylindrocarpon sp., Chaetomium sp., Paraphaeosphaeria sporulosa, Pyrenochaeta sp., Penicillium swiecickii, T. viride, and Truncatella angustata were found only in the oldest plants. Analysis of(metagenomics) community DNA extracted from different-aged samples revealed that, at the class level,the majority of fungi had the highest sequence similarity to members of Sordariomycetes, followed by Eurotiomycetes and Saccharomycetes. These results were mostly in accord with those we obtained using culture methods. Fungal diversity and richness also changed over time. Our investigation is the first to show that the diversity of fungi in rhizomes of P. polyphylla var. yunnanensis is altered as plants age, and our findings provide a foundation for future examinations of useful compounds.
基金This study was funded by the Special Fund for Agro- scientific Research in the Public Interest in China （Grant No. 201203036）, Natural Science Foundation of Zhejiang （Project No. D3080388） and National 973 Project （Project No. 2012CB11410005）.
文摘Olfaction is primarily mediated by highly specified olfactory receptors （ORs）. Here, we cloned and identified an olfactory receptor, named SlituOR1 （Genbank no. JN835269）, from Spodoptera litura and found evidence that it is a candidate pheromone receptor. It exhibited male-biased expression in the antennae, where it was localized at the base of sensilla trichoidea, the antennal sensilla mainly responsive to pheromones in moths. Conserved orthologues of this receptor, found among known pheromone receptors within the Lepidoptera, and SlituOR1 were placed among a clade of candidate pheromone re- ceptors in a phylogeny tree of insect OR gene sequences. SlituOR1 showed differential expression in S. litura populations attracted to traps baited with different ratios of the two sex pheromone components （9Z,11E）-tetradecadienyl acetate （Z9E11-14：OAc） and （9Z,12E）-tetradecadienyl acetate （Z9E12-14：OAc）. Knocking down of SlituOR1 by RNA interference reduced the electroantennogram （EAG） response to Z9E11-14：OAc, and this result is consistent with the field trapping experiment. We infer that variation in transcrip- tion levels of olfactory receptors may modulate sex pheromone perception in male moths and could provide some of the flexibility required to maintain the functionality of com- munication with females when a population is adapting to a new niche and reproductive isolation becomes an advantage.
