2007 Fiscal Year Final Research Report Summary
Investigation of the genes for norlignan biosynthetic enzymes through the large-scale collection of genes expressed in the xylem of Sugi(Cryptomeria Japonica).
| Project/Area Number |
17580147
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林産科学・木質工学
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| Research Institution | Forestry and Forest Products Research Institute |
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Principal Investigator |
YOSHIDA Kazumasa Forestry and Forest Products Research Institute, Department of Molecular and Cell Biology, Head (50353909)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Sugi / Norlignan / Secondary metabolite / Biosynthesis / Enzyme / Gene |
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| Research Abstract |
In this research, I aimed to identify enzymes involved in the norlignan biosynthesis in Sugi (Cryptomeria japonica) through the isolation of genes for enzymes and analysis of their enzyme activities. A trunk section was excised from the log of Sugi, and stored in a room. Analysis of norlignans in sapwood collected on Days 0, 10, 20 and 41 post-harvest revealed the prominent increase of a norlignan, agatharesinol, from Day 20 to 41, though it was not detected on Day 0. Suppression subtracted hybridization was performed using the cDNA from the sapwood on Days 0 and 41, respectively, and constructed a cDNA library enriched with genes preferentially expressed on Day 41. From this library, sequences of 504 non-redundant expressed sequences tags were obtained. In these sequences, those for 16 genes encoding putative enzymes were assigned to secondary metabolism based on the similarity to known sequences with predicted functions.
The expressions of 12 genes in the secondary metabolism were upregulated in the sapwood of the trunk section with the passage of days. In addition, five of 12 genes were expressed in the transition zone in November when the heartwood formation is assumed to be in progress. Considering that agatharesinol is a heartwood constituent, It was postulated that the genes for enzymes involved in the agatharesinol biosynthesis was included among them. Although the recombination protein of putative tyrosine 3-monooxygenase was prepared from the full-length cDNA using the recombinant bacteria, the enzyme activity could not be detected. There is only one report on isolation of tyrosine 3-monooxygenase from plant, and it was from a herb. Not only to gain an insight into norlignan biosynthesis but also to reveal the role of this enzyme in woody plants, characteristic of the enzyme should be clarified.
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