As a retrotransposon, TOS17 was a useful tool for rice genetic and functional genomic research. To ascertain the feasibility of constructing a TOS17 insertion mutation library in the rice cultivar Shishoubaimao, the g...As a retrotransposon, TOS17 was a useful tool for rice genetic and functional genomic research. To ascertain the feasibility of constructing a TOS17 insertion mutation library in the rice cultivar Shishoubaimao, the genetic and expression characteristics of TOS17 were analyzed. We made solid and suspension tissue cultures and confirmed the copy numbers of TOS17 at different time points in both tissue culture processes by real-time quantitative PCR （RT-qPCR）. Three primary copies of TOS17 were detected in naturally grown Shishoubaimao. TOS17 was activated by tissue culture, and the copy numbers of TOSI7 increased along with a prolonged tissue culture time in both the Nipponbare and the Shishoubaimao cultivars. Therefore, Shishoubaimao is a potential candidate for constructing a TOS17 insertion mutant library. Compared with Nipponbare, TOS17 was more active in Shishoubaimao during tissue culture. Higher copy numbers of TOS17 were obtained with the suspension tissue culture process than with the solid tissue culture process over the same time courses. We concluded that 3-4 months of suspension tissue culture time is suitable for constructing a TOS17 insertion mutant library in Shishoubaimao.展开更多
Heritable alteration in DNA methylation patterns was detected in all five rice lines with introgressed DNA segments from wild rice(Zizania latifolia(Griseb.))by DNA gel blotting analys iswith an endogenous retrotransp...Heritable alteration in DNA methylation patterns was detected in all five rice lines with introgressed DNA segments from wild rice(Zizania latifolia(Griseb.))by DNA gel blotting analys iswith an endogenous retrotransposon Tos/7as a probe.The changing patterns include simultaneous loss of parental fragments and appearance of novel fragments in each of the four methylation-sensitive enzyme digests.Methylation modifications include cytosines at both symmetrical and asymmetrical sites,as well as adenine bases.Sequence ana lysis at two critical regions of Tos/7,i.e.the 5'-LTR region(region I)and the reverse transcriptase region(region II)showed complete conservation for all five introgression lines compared with the parent.Sequence-specific PCR assay,however,confirmed that methylation changes occurred in both regions,Moreover,concordance in the collective methylation changes between 5'-LTR and RT regions was observed in two of the introgression lines.The methylation changes are stably inherited to the next generation.Because earlier studies showed that there had been activation and mobilization of Tos/7 in these introgression lines following alien DNA integration,it appears likely that DNA methylation may have played some roles in controlling activity of Tos/7in rice,although the exact relationship between the two phenomena remains to be established.展开更多
Auxin signaling plays a key role in the regulation of various growth and developmental processes in higher plants. Auxin response factors (ARFs) are transcription factors that regulate the expression of auxin-response...Auxin signaling plays a key role in the regulation of various growth and developmental processes in higher plants. Auxin response factors (ARFs) are transcription factors that regulate the expression of auxin-response genes. The osarf24-1 mutant contains a truncation of domain IV in the C-terminal dimerization domain of a rice ARF protein, OsARF24. This mutant showed auxin-deficient phenotypes and reduced sensitivity to auxin. However, OsARF24 protein contains an SPL-rich repression domain in its middle region and acts as a transcriptional repressor. These results imply that the C-terminal dimerization domain, especially the C-terminal half of domain IV, is essential for the proper regulation of OsARF24 function as a transcriptional repressor in rice.展开更多
基金supported by the National 973 Program of China (2005CB120903)
文摘As a retrotransposon, TOS17 was a useful tool for rice genetic and functional genomic research. To ascertain the feasibility of constructing a TOS17 insertion mutation library in the rice cultivar Shishoubaimao, the genetic and expression characteristics of TOS17 were analyzed. We made solid and suspension tissue cultures and confirmed the copy numbers of TOS17 at different time points in both tissue culture processes by real-time quantitative PCR （RT-qPCR）. Three primary copies of TOS17 were detected in naturally grown Shishoubaimao. TOS17 was activated by tissue culture, and the copy numbers of TOSI7 increased along with a prolonged tissue culture time in both the Nipponbare and the Shishoubaimao cultivars. Therefore, Shishoubaimao is a potential candidate for constructing a TOS17 insertion mutant library. Compared with Nipponbare, TOS17 was more active in Shishoubaimao during tissue culture. Higher copy numbers of TOS17 were obtained with the suspension tissue culture process than with the solid tissue culture process over the same time courses. We concluded that 3-4 months of suspension tissue culture time is suitable for constructing a TOS17 insertion mutant library in Shishoubaimao.
基金Supported by the National Science Fund for Distinguished Young Scholars of China(30225003)the Outstanding Youth Research Plans of the Jilin Provincial Government
文摘Heritable alteration in DNA methylation patterns was detected in all five rice lines with introgressed DNA segments from wild rice(Zizania latifolia(Griseb.))by DNA gel blotting analys iswith an endogenous retrotransposon Tos/7as a probe.The changing patterns include simultaneous loss of parental fragments and appearance of novel fragments in each of the four methylation-sensitive enzyme digests.Methylation modifications include cytosines at both symmetrical and asymmetrical sites,as well as adenine bases.Sequence ana lysis at two critical regions of Tos/7,i.e.the 5'-LTR region(region I)and the reverse transcriptase region(region II)showed complete conservation for all five introgression lines compared with the parent.Sequence-specific PCR assay,however,confirmed that methylation changes occurred in both regions,Moreover,concordance in the collective methylation changes between 5'-LTR and RT regions was observed in two of the introgression lines.The methylation changes are stably inherited to the next generation.Because earlier studies showed that there had been activation and mobilization of Tos/7 in these introgression lines following alien DNA integration,it appears likely that DNA methylation may have played some roles in controlling activity of Tos/7in rice,although the exact relationship between the two phenomena remains to be established.
文摘Auxin signaling plays a key role in the regulation of various growth and developmental processes in higher plants. Auxin response factors (ARFs) are transcription factors that regulate the expression of auxin-response genes. The osarf24-1 mutant contains a truncation of domain IV in the C-terminal dimerization domain of a rice ARF protein, OsARF24. This mutant showed auxin-deficient phenotypes and reduced sensitivity to auxin. However, OsARF24 protein contains an SPL-rich repression domain in its middle region and acts as a transcriptional repressor. These results imply that the C-terminal dimerization domain, especially the C-terminal half of domain IV, is essential for the proper regulation of OsARF24 function as a transcriptional repressor in rice.
