-
[show abstract]
[hide abstract]
ABSTRACT: Pyripyropenes are potent inhibitors of acyl-CoA:cholesterol acyltransferase, which were initially discovered to be produced by Aspergillus fumigatus. Recently, Penicillium coprobium PF1169 has also found to produce pyripyropene A (PyA), which exhibits insecticidal properties. Pyripyropenes are natural hybrid products of both terpenoid and polyketide origin. In our research, based on data generated using the Genome Sequencer FLX for P. coprobium PF1169, we predicted the biosynthetic gene cluster of PyA by blast analysis comparing with polyketide synthase and prenyltransferase of other species. By screening the genomic fosmid library, nine open reading frames (ppb1 to ppb9) related to the biosynthesis of PyA were deduced. Among them, two cytochrome P450 monooxygenase genes (ppb3 and ppb4) were separately introduced into the model fungus A. oryzae. Bioconversion of certain predicted intermediates in the transformants has elucidated the manner of hydroxylation in the biosynthetic pathway by the expressed products of these two genes (P450-1 and P450-2). That is, P450-1 exhibits monooxygenase activity and plays the hydroxylation role at C-11 of pyripyropene E. While P450-2 plays an active role in the hydroxylation of C-7 and C-13 of pyripyropene O.
The Journal of Antibiotics 01/2011; 64(3):221-7. · 1.65 Impact Factor
-
Journal of the American Society for Horticultural Science. American Society for Horticultural Science 11/2009; · 0.94 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Systemic acquired resistance (SAR), a natural disease response in plants, can be induced chemically. Salicylic acid (SA) acts as a key endogenous signaling molecule that mediates SAR in dicotyledonous plants. However, the role of SA in monocotyledonous plants has yet to be elucidated. In this study, the mode of action of the agrochemical protectant chemical probenazole was assessed by microarray-based determination of gene expression. Cloning and characterization of the most highly activated probenazole-responsive gene revealed that it encodes UDP-glucose:SA glucosyltransferase (OsSGT1), which catalyzes the conversion of free SA into SA O-beta-glucoside (SAG). We found that SAG accumulated in rice leaf tissue following treatment with probenazole or 2,6-dichloroisonicotinic acid. A putative OsSGT1 gene from the rice cultivar Akitakomachi was cloned and the gene product expressed in Escherichia coli was characterized, and the results suggested that probenazole-responsive OsSGT1 is involved in the production of SAG. Furthermore, RNAi-mediated silencing of the OsSGT1 gene significantly reduced the probenazole-dependent development of resistance against blast disease, further supporting the suggestion that OsSGT1 is a key mediator of development of chemically induced disease resistance. The OsSGT1 gene may contribute to the SA signaling mechanism by inducing up-regulation of SAG in rice plants.
The Plant Journal 10/2008; 57(3):463-72. · 6.16 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Fourteen microsatellite markers were developed from an enriched genomic library of Japanese pear (Pyrus pyrifolia) by selective hybridization. They were characterized using 17 Japanese pear cultivars. The expected heterozygosity and observed heterozygosity ranged from 0.21 to 0.74 and from 0 to 0.88, respectively. Two to 11 alleles were detected per locus, with IPPN09 and IPPN15 judged to amplify multiple loci. IPPN17 was the most informative locus with the lowest probability of identity (0.19). These primers exhibited a high cross-species transferability between species and genera.
Molecular Ecology Notes 11/2006; 7(3):445 - 447. · 2.38 Impact Factor
-
Breeding Science 06/2005; · 1.25 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The Agrobacterium-mediated transformation system was extended to a famous Javanica rice variety, Rojolele, that is cultivated in Indonesia now. Efficient callus induction from immature and mature seeds of Rojolele did not succeed by any previous method for any rice cultivar. In this study, the callus from mature seeds of Rojolele exhibited a compact and nodular appearance on C medium after the carbon source and medium pH was modified. Scutellum-derived calli from mature seeds were co-cultivated with Agrobacterium tumefaciens strains EHA101 or LBA4404 that carried plasmid pAFT14, which contained the genes for beta-glucuronidase (gus) and hygromycin resistance (hpt). Finally, the transformation efficiency of Rojolele variety using A. tumefaciens strain EHA101 (pAFT14) was improved to about 23%, similar to that of the Japonica rice variety Nipponbare. The seed fertility of transgenic Rojolele was more than 90%. The copy number of the transgene varied from one to three copies in the T(0) transgenic lines. Both the gus and the hpt genes were inherited and expressed in the progeny.
Bioscience Biotechnology and Biochemistry 07/2004; 68(6):1193-200. · 1.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Efficient synthetic methods for the construction of a wide variety of unsymmetrical tetrathiafulvalenes (TTFs) via the Me(3)Al-promoted reactions of organotin thiolates or selenolates with esters are described. Reaction of tin thiolates (3a-c and 10) and selenolates (3d, 5, and 7) with esters (11a,b) in the presence of Me(3)Al as a Lewis acid gave dihydrotetrathiafulvalene derivatives (12, 14, 15, and 17-20) and 1,3-dithiane derivatives (13 and 16). In addition, the synthesis of diselenadithiafulvalene derivatives (25-28) could be accomplished by Me(3)Al-mediated reaction of tin thiolate (2a) or selenolates (3d and 5) with esters (22a, 22d, and 24). Furthermore, the application of the Me(3)Al-promoted reaction of tin thiolate (34) with esters (11a-b, 22a-d, and 35a-b) for the synthesis of unsymmetrical TTFs-fused donors enabled us to obtain various TTFs-fused systems (29-33) in short steps.
The Journal of Organic Chemistry 07/1996; 61(12):3987-3995. · 4.45 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We have constructed a chimeric gene consisting of the promoter, first exon, and first intron of a maize ubiquitin gene (Ubi-1) and the coding sequence of the bar gene from Streptomyces hygroscopicus. This construct was transferred into rice (Oryza sativa L.) protoplasts via electroporation, and 10 plants were regenerated from calli that had been selected for resistance to exogenously supplied bialaphos. Transgenic plants grown in a greenhouse were resistant to both bialaphos and phosphinothricine at a dosage lethal to untransformed control plants. Evidence of stable integration of the transferred gene into the genome of the regenerated primary transformant plants was obtained from Southern blot analysis. In addition, northern blot analysis indicated expression and proper splicing of the maize ubiquitin gene first intron from the primary chimeric transcript in these transgenic rice plants, and western blot analysis and enzymic assays verified expression of the active bar gene product. Apparent mendelian segregation for bialaphos resistance in T(1) progeny of primary transformants was confirmed.
Plant physiology 12/1992; 100(3):1503-7. · 6.53 Impact Factor
