Variation of two simple sequence repeats (SSRs) in the leader region of the waxy gene was analyzed in a sample of 74 accessions, including Oryza sativa L. ssp. indica, japonica and wild rice (O.rufipogon) represen...Variation of two simple sequence repeats (SSRs) in the leader region of the waxy gene was analyzed in a sample of 74 accessions, including Oryza sativa L. ssp. indica, japonica and wild rice (O.rufipogon) representing a wide distribution range of amylose content (AC) in cultivated rice. Eight alleles were detected in the (CT) n motif and two alleles were resolved in the (AATT) n motif. The distribution of the alleles of the two SSRs was quite uneven as detected by the (CT) n motif. The repeat numbers of the two SSR motifs, (CT) n and (AATT) n, appeared to be inversely related such that the total length of this region was maintained. AC of the varieties was highly correlated with the length of SSRs. Differences in AC among the various SSR genotypes were statistically highly significant as analyzed using genotypes of both SSR motifs. Although the SSR variation did not seem to have obvious function in the synthesis of the starch synthase encoded by the waxy gene, the almost perfect correlation between the two SSRs and AC level could be used for quality improvement in rice breeding programs.展开更多
cDNA encoding caffeoyl CoA O-methyltransferase (CCoAOMT) from Chinese white poplar ( Populus tomentosa Carr.) was cloned by RT-PCR and sequenced. Northern analysis displayed that the CCoAOMT was expressed specifically...cDNA encoding caffeoyl CoA O-methyltransferase (CCoAOMT) from Chinese white poplar ( Populus tomentosa Carr.) was cloned by RT-PCR and sequenced. Northern analysis displayed that the CCoAOMT was expressed specifically in the developing secondary xylem and its expression was coincident with lignification. The antisense CCoAOMT cDNA was transformed into P. tremula x P. alba mediated by Agrobacterium tumefaciens ( Smith et Townsend) Conn. Transgenic plants were identified with PCR, PCR-Southern and Southern analysis. Lignin content in 5- to 6-month-old transgenic plants was measured. One of the transgenic lines had significant reduction of 17.9% in Klason lignin content as compared with that of untransformed poplar. The results demonstrate that antisense repression of CCoAOMT is an efficient way to reduce lignin content for improving pulping property in engineered trees.展开更多
A new method was used to preparing genomic DNA from Microbacterium sp.quickly and efficiently.DNA quantity and purity was measured by UV absorbance.Integrity of the genomic DNA was tested by agarose gel eletrophoresis...A new method was used to preparing genomic DNA from Microbacterium sp.quickly and efficiently.DNA quantity and purity was measured by UV absorbance.Integrity of the genomic DNA was tested by agarose gel eletrophoresis.The DNA prepared by this method was sufficiently pure for PCR.This method saves time and cost,practices easily as well.展开更多
文摘Variation of two simple sequence repeats (SSRs) in the leader region of the waxy gene was analyzed in a sample of 74 accessions, including Oryza sativa L. ssp. indica, japonica and wild rice (O.rufipogon) representing a wide distribution range of amylose content (AC) in cultivated rice. Eight alleles were detected in the (CT) n motif and two alleles were resolved in the (AATT) n motif. The distribution of the alleles of the two SSRs was quite uneven as detected by the (CT) n motif. The repeat numbers of the two SSR motifs, (CT) n and (AATT) n, appeared to be inversely related such that the total length of this region was maintained. AC of the varieties was highly correlated with the length of SSRs. Differences in AC among the various SSR genotypes were statistically highly significant as analyzed using genotypes of both SSR motifs. Although the SSR variation did not seem to have obvious function in the synthesis of the starch synthase encoded by the waxy gene, the almost perfect correlation between the two SSRs and AC level could be used for quality improvement in rice breeding programs.
文摘cDNA encoding caffeoyl CoA O-methyltransferase (CCoAOMT) from Chinese white poplar ( Populus tomentosa Carr.) was cloned by RT-PCR and sequenced. Northern analysis displayed that the CCoAOMT was expressed specifically in the developing secondary xylem and its expression was coincident with lignification. The antisense CCoAOMT cDNA was transformed into P. tremula x P. alba mediated by Agrobacterium tumefaciens ( Smith et Townsend) Conn. Transgenic plants were identified with PCR, PCR-Southern and Southern analysis. Lignin content in 5- to 6-month-old transgenic plants was measured. One of the transgenic lines had significant reduction of 17.9% in Klason lignin content as compared with that of untransformed poplar. The results demonstrate that antisense repression of CCoAOMT is an efficient way to reduce lignin content for improving pulping property in engineered trees.
文摘A new method was used to preparing genomic DNA from Microbacterium sp.quickly and efficiently.DNA quantity and purity was measured by UV absorbance.Integrity of the genomic DNA was tested by agarose gel eletrophoresis.The DNA prepared by this method was sufficiently pure for PCR.This method saves time and cost,practices easily as well.
