Phytocassanes A, B, C and D, novel diterpene phytoalexins from rice, Oryza sativa L.

Koga, Jinichiro; Shimura, Masaru; Oshima, Kiyomi; Ogawa, Naoko; Yamauchi, Toyozo; Ogasawara, Nagahiro

doi:10.1016/0040-4020(95)00423-6

Cited by 126 publications

(94 citation statements)

References 16 publications

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“…BL-1) 0, 3,6,8,10, and 12 h after adding the chitin elicitor (10 ppm). PCR was carried out using Ex Taq DNA polymerase (TaKaRa, Ohtsu, Japan) with the following program: 5 min at 94°C, followed by 30 cycles of 1 min at 94°C, 1 min at 56°C…”

Section: Expression Analysis Ofmentioning

confidence: 99%

“…Four structurally distinct types of polycyclic diterpenoid phytoalexins, oryzalexins A-F [3][4][5], ())-phytocassanes A-E [6][7][8], momilactones A and B [9,10], and oryzalexin S [11], have been identified in extracts of the leaves of rice plants that were either infected with the rice leaf blast pathogen, Magnaporthe grisea, or exposed to ultra-violet (UV)-irradiation. The proposed pathways for biosynthesis of diterpenoid phytoalexins in rice are illustrated in Fig.…”

Section: Introductionmentioning

confidence: 99%

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Stemar‐13‐ene synthase, a diterpene cyclase involved in the biosynthesis of the phytoalexin oryzalexin S in rice

et al. 2004

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In suspension-cultured rice cells, diterpenoid phytoalexins are produced in response to exogenously applied elicitors. We isolated a cDNA encoding a diterpene cyclase, OsDTC2, from suspension-cultured rice cells treated with a chitin elicitor. The OsDTC2 cDNA was overexpressed in Escherichia coli as a fusion protein with glutathione S-transferase, and the recombinant OsDTC2 was indicated to function as stemar-13-ene synthase that converted syn-copalyl diphosphate to stemar-13-ene, a putative diterpene hydrocarbon precursor of the phytoalexin oryzalexin S. The level of OsDTC2 mRNA in suspension-cultured rice cells began to increase 3 h after addition of the elicitor and reached the maximum after 8 h. The expression of OsDTC2 was also induced in UV-irradiated rice leaves. In addition, we indicated that stemar-13-ene accumulated in the chitin-elicited suspension-cultured rice cells and the UVirradiated rice leaves.

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Section: Expression Analysis Ofmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stemar‐13‐ene synthase, a diterpene cyclase involved in the biosynthesis of the phytoalexin oryzalexin S in rice

et al. 2004

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“…1). These compounds include momilactones A and B (Kato et al, 1973;Cartwright et al, 1981), oryzalexins A-F (Akatsuka et al, 1985;Sekido et al, 1986;Kato et al, 1993Kato et al, , 1994, oryzalexin S (Kodama et al, 1992), and phytocassanes A-E (Koga et al, 1995(Koga et al, , 1997. All of these natural products exhibit antimicrobial properties and are synthesized as part of the defensive response to leaf infection with the blast pathogenic fungus Magneportha grisea, thus qualifying as phytoalexins (VanEtten et al, 1994).…”

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confidence: 99%

Identification of Syn-Pimara-7,15-Diene Synthase Reveals Functional Clustering of Terpene Synthases Involved in Rice Phytoalexin/Allelochemical Biosynthesis

et al. 2004

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Rice (Oryza sativa) produces momilactone diterpenoids as both phytoalexins and allelochemicals. Accordingly, the committed step in biosynthesis of these natural products is catalyzed by the class I terpene synthase that converts syn-copalyl diphosphate to the corresponding polycyclic hydrocarbon intermediate syn-pimara-7,15-diene. Here, a functional genomics approach was utilized to identify a syn-copalyl diphosphate specific 9b-pimara-7,15-diene synthase (OsDTS2). To our knowledge, this is the first identified terpene synthase with this particular substrate stereoselectivity and, by comparison with the previously described and closely related ent-copalyl diphosphate specific cassa-12,15-diene synthase (OsDTC1), provides a model system for investigating the enzymatic determinants underlying the observed difference in substrate specificity. Further, OsDTS2 mRNA in leaves is up-regulated by conditions that stimulate phytoalexin biosynthesis but is constitutively expressed in roots, where momilactones are constantly synthesized as allelochemicals. Therefore, transcription of OsDTS2 seems to be an important regulatory point for controlling production of these defensive compounds. Finally, the gene identified here as OsDTS2 has previously been mapped at 14.3 cM on chromosome 4. The class II terpene synthase producing syn-copalyl diphosphate from the universal diterpenoid precursor geranylgeranyl diphosphate was also mapped to this same region. These genes catalyze sequential cyclization steps in momilactone biosynthesis and seem to have been evolutionarily coupled by physical linkage and resulting cosegregation. Further, the observed correlation between physical proximity and common metabolic function indicates that other such class I and class II terpene synthase gene clusters may similarly catalyze consecutive reactions in shared biosynthetic pathways.Plants produce a vast and diverse array of low-molecular weight organic compounds, the overwhelming majority of which are secondary metabolites with nonessential, yet important, functions such as defense . For example, phytoalexins are produced in response to microbial infections and exhibit antimicrobial activity (VanEtten et al., 1994), while allelochemicals are secreted to the rhizosphere and suppress the growth of neighboring plants (Bais et al., 2004). Often found serving in such roles are terpenoids, which are particularly abundant in plant metabolism and form the largest class of natural products, exhibiting wide diversity in chemical structure and biological function . Much of the structural variation within this class arises from the diverse carbon backbones formed by terpene synthases (cyclases). These divalent metal dependent enzymes carry out complex electrophilic cyclizations/ rearrangements to create these diverse skeletal structures from relatively simple acyclic precursors (Davis and Croteau, 2000). Notably, production of a specific backbone structure either dictates, or at least severely restricts, the metabolic fate of that particular molecule. Thus,...

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“…1), [6][7][8][9] and phytocassanes (phytoalexin, Fig. 1) [10][11][12] have been isolated from plants. Similarly, fungal GAs, 13) aphidicolin (a specific inhibitor of DNA polymerase ), 14,15) and fusicoccin A (a diterpene glucoside that acts as a plant plasma membrane H þ -ATPase activator) 16,17) have been isolated from fungi.…”

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confidence: 99%

Recent Advances Regarding Diterpene Cyclase Genes in Higher Plants and Fungi

Toyomasu

2008

Bioscience, Biotechnology, and Biochemistry

100

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Cyclic diterpenoids are commonly biosynthesized from geranylgeranyl diphosphate (GGDP) through the formation of carbon skeletons by specific cyclases and subsequent chemical modifications, such as oxidation, reduction, methylation, and glucosidation. A variety of diterpenoids are produced in higher plants and fungi. Rice produces four classes of diterpene phytoalexins, phytocassanes A to E, oryzalexins A to F, oryzalexin S, and momilactones A and B. The six diterpene cyclase genes involved in the biosynthesis of these phytoalexins were identified and characterized. Fusicoccin A was produced by the phytopathogenic Phomopsis amygdali and served as a plant H þ -ATPase activator. A PaFS, encoding a fungal diterpene synthase responsible for fusicoccin biosynthesis, was isolated. The PaFS is an unusual chimeric diterpene synthase that possesses not only terpene cyclase activity (the formation of fusicoccadiene, a biosynthetic precursor of fusicoccin A), but also prenyltransferase activity (the formation of GGDP). Thus, we identified a unique multifunctional diterpene synthase family in fungi.

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Phytocassanes A, B, C and D, novel diterpene phytoalexins from rice, Oryza sativa L.

Cited by 126 publications

References 16 publications

Stemar‐13‐ene synthase, a diterpene cyclase involved in the biosynthesis of the phytoalexin oryzalexin S in rice

Stemar‐13‐ene synthase, a diterpene cyclase involved in the biosynthesis of the phytoalexin oryzalexin S in rice

Identification of Syn-Pimara-7,15-Diene Synthase Reveals Functional Clustering of Terpene Synthases Involved in Rice Phytoalexin/Allelochemical Biosynthesis

Recent Advances Regarding Diterpene Cyclase Genes in Higher Plants and Fungi

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