| Tea flower is the reproductive organ of Camellia sinensis?L.?O.Kuntze.It is a bisexual complete flower,being rich in nutrients and active substances.The area of tea plantations in China is the largest throught the world and the resources of tea flower are very rich.So tea flower is a potential resource with the enormous exploiting value.In the present work,both difference in expression of Cu/Zn-SOD gene in tea flowers from several cultivars and the attraction effect of their volatiles on Chinese honeybee were studied.It can provide reference for the exploitation of tea flower in the field of food and ecology.The main results were as follows:?1?The analysis of the expression of Cu/Zn-SOD gene of tea flowers among tea cultivars showed that the expression of Cu/Zn-SOD much differed among the various developmental stages,and the expression of cytoplasmic Cu/Zn-SOD1 gene was much higher than those of chloroplast type Cu/Zn-SOD2 and peroxisome Cu/Zn-SOD3.The expression of Cu/Zn-SOD in different cultivars of tea flowers were significantly different.Cu/Zn-SOD1 gene exhibited the highest expression in cultivar‘Huangmudan'tea flower,Cu/Zn-SOD2 gene has the highest expression in cultivars‘Anjibaicha'and‘Huangguanyin'tea flowers,and Cu/Zn-SOD3 gene has the highest expression in cultivar‘Zijuan'tea flowers.However,there is no significant correlation between the activity of Cu/Zn-SOD enzyme and the expression Cu/Zn-SOD gene in both different developmental stages of‘Longjing 43'tea flowers and various tea cultivars.?2?The analytic results of the main ingredients of tea flowers showed that tea flowers owned the ample moisture and water extract.The contents of both soluble protein and soluble sugar in tea flowers were slightly lower than those in fresh leaves.Although the content of tea polyphenol was significantly lower than that in fresh leaves,the content of free amino acid was almost equal to to that of fresh leaves.?3?Based on Y-tube olfactometer,the behavioral bioassays of Chinese honeybee?Apis cerana?to the following odor sources were executed,i.e.the odors of flowers of various national level elite tea cultivars,the main aromatic compounds of tea flowers,and the important volatile odor compounds of tea fresh leaves.Results showed that:?1?the aroma of flowers of the eight elite tea cultivars significantly attracted Chinese honeybees within a certain dose range?P<0.05?;?2?twenty-seven main volatile components,identified from tea flowers,were respectively prepared into three dosages as odor sources with liquid paraffin as solvent,against liquid paraffin as CK;acetophenone?10-66 g/mL?,linalool(10-6,10-2 g/mL),camphene(10-4g/mL),Z-3-hexen-1-ol?10-1010 g/mL?,?-farnesene(10-6,10-4,10-22 g/mL),decanal(10-6g/mL),b-lonone?10-66 g/mL?,linoleic acid(10-4,10-22 g/mL),Z-2-penten-1-ol(10-4g/mL),and benzaldehyde?10-22 g/mL?attracted the honeybee?P<0.05?,whilst methyl salicylate?10-22 g/mL?,nerol?10-22 g/mL?,and octanal?10-66 g/mL?disclosed a significant repelled effect?P<0.05?;?3?twenty-four volatile components identified from tea fresh leaves were also prepared into odor sources,and octadecanol(10-4g/mL),octanol?10-22 g/mL?,indol?10-66 g/mL?,citral?10-22 g/mL?,menthol?10-66 g/mL?,?-caryophyllene?10-44 g/mL?and menthone(10-4,10-22 g/mL)displayed a significant attraction to the honeybee?P<0.05?,whereas o-cresol?10-22 g/mL?,?-citronellol(10-6g/mL),1,3-propanediol?10-22 g/mL?,?-terpinene?10-66 g/mL?,and pentanol?10-44 g/mL?significantly repelled the honeybee?P<0.05?.It was considered that the main components of both tea flowers and tea leaves significantly attracted the honeybee,especially acetophenone and linalool,both of whom respectively accounted for 20%of tea flower aroma,intensively attracting the honeybees,which resulted in the honeybees occupied themselves special hobby for the tea garden in the blossom seasons.?4?Terpenoids play an important role in the exchange of information between many species of plants and between plant and insect.This study found that?-farnesene has an attractive effect on Chinese honeybees.?-Farnesene synthase is the direct rate-limiting enzyme in the synthesis of?-farnesene,which has a very important regulatory effect on the synthesis of?-farnesene.A full-length cDNA sequence of?-farnesene synthase gene,named as CsFAS?Genbank:MH686504?from tea flowers,was cloned by RACE.The full-length gene was 2082 bp with a 75bp 5'UTR,a 1683 bp ORF,a 324 bp 3'UTR and poly?A?tail,which encoded a total of 560 amino acids.The encoded amino acid sequence contained an RR?X8?W region and a DDXXD region.The E.coli expression vector of gene was constructed,and it was found that the recombinant protein existed in the form of inclusion bodies. |
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