DNA damage in the form of cyclobutane pyrimidine dimers(CPDs) and (6-4) photoproducts(6-4PPs) induced by UV-B radiation in Arabidopsis thaliana at different temperatures was investigated using ELISA with specific mono...DNA damage in the form of cyclobutane pyrimidine dimers(CPDs) and (6-4) photoproducts(6-4PPs) induced by UV-B radiation in Arabidopsis thaliana at different temperatures was investigated using ELISA with specific monoclonal antibodies. CPDs and 6-4PPs increased during 3 h UV-B exposure, but further exposure led to decreases. Contrary to the commonly accepted view that DNA damage induced by UV-B radiation is temperature-independent because of its photochemical nature, we found UV-B-induction of CPDs and 6-4PPs in Arabidopsis to be slower at a low than at a high temperature. Photorepair of CPDs at 24℃ was much faster than that at 0℃ and 12℃, with 50% CPDs removal during 1 h exposure to white light. Photorepair of 6-4PPs at 12℃ was very slow as compared with that at 24℃, and almost no removal of 6-4PPs was detected after 4 h exposure to white light at 0℃. There was evidence to suggest that temperature-dependent DNA damage and photorepair could have important ecological implications.展开更多
The age structure of the natural Zoysia japonica clonal population at QipanMountain in Huishan Scenic Spot of Shenyang, Liaoning Province, China was studied using themorphological method in 2003 and 2004. The dynamics...The age structure of the natural Zoysia japonica clonal population at QipanMountain in Huishan Scenic Spot of Shenyang, Liaoning Province, China was studied using themorphological method in 2003 and 2004. The dynamics of leaves were recorded and the dynamics oftiller and rhizome in the growing season were observed. The results indicated that the rhizomesformed in different years changed in color and rigidity. Its internodes produced in autumn becameshorter. The number of naked nodes changed with the tiller age. Rhizome and tiller characters wereused as a foundation for judging the ages of modules in this study. The longevity of tiller andrhizome was 3 years at most. At the beginning of the growing season, 2-year-old tillers and rhizomespredominated. Then 1-year-old tillers and rhizomes increased rapidly and became dominant in July.The proportion of buds to tillers on quantity was stable at about 30% in the mid-phase of thegrowing season and rose to about 50% in autumn. The seasonal dynamics of tiller, rhizome and bud wasvery important to guarantee the sustained existence of the Zoysia japonica population. The turnoverof modules was the mechanism of sustaining the rejuvenation of the Zoysiajaponica clonalpopulation.展开更多
ARC and ND colony were obtained by rearing the whitebacked planthopper (WBPH), Sogatella furcifera (Horvath), exclusively on ARC10239 (ARC, carrying resistance gene Wbph2) and N'Diang Marie (ND, carrying resistanc...ARC and ND colony were obtained by rearing the whitebacked planthopper (WBPH), Sogatella furcifera (Horvath), exclusively on ARC10239 (ARC, carrying resistance gene Wbph2) and N'Diang Marie (ND, carrying resistance gene Wbph5) till 15 generations. Taichung Native 1 (TN1) and Rathu Heenati (RHT) served as susceptible and resistant check, respectively. The results of electronic recording revealed that duration of salivation and X-waveform of the two colonies on their corresponding hosts was short while the duration of phloem ingestion was long. The amount of honeydew excreted by ARC and ND colony did not differ on their corresponding host varieties from TN1 and was much higher than that of RHT. The number of eggs laid on their host varieties and TN1 were significantly higher than that on RHT. No distinct change was observed for these two colonies in term of percentage of developed eggs. The nymph survival rate of ND colony on its selection host was 45.0%, significantly different from that on TNI(71.4%) and RHT(21.0%), while that of ARC colony was 68.3%, not significantly different from that on TN1 (77.5%), but much higher than that on RHT(22.6%). The nymphal development duration of these two colonies on the corresponding hosts was not different from that on TN1, but significantly shorter than that on RHT. In brief, these two colonies had almost adapted to their corresponding host varieties based on feeding and oviposition, but the nymphal survival rate of ND colony was still low.展开更多
文摘DNA damage in the form of cyclobutane pyrimidine dimers(CPDs) and (6-4) photoproducts(6-4PPs) induced by UV-B radiation in Arabidopsis thaliana at different temperatures was investigated using ELISA with specific monoclonal antibodies. CPDs and 6-4PPs increased during 3 h UV-B exposure, but further exposure led to decreases. Contrary to the commonly accepted view that DNA damage induced by UV-B radiation is temperature-independent because of its photochemical nature, we found UV-B-induction of CPDs and 6-4PPs in Arabidopsis to be slower at a low than at a high temperature. Photorepair of CPDs at 24℃ was much faster than that at 0℃ and 12℃, with 50% CPDs removal during 1 h exposure to white light. Photorepair of 6-4PPs at 12℃ was very slow as compared with that at 24℃, and almost no removal of 6-4PPs was detected after 4 h exposure to white light at 0℃. There was evidence to suggest that temperature-dependent DNA damage and photorepair could have important ecological implications.
基金This study was supported by Doctor Startup Foundation of Liaoning Province (20031029), Doctor Startup Foundation of Shenyang Normal University and Director Foundation of Shenyang Normal University (sy200513).
文摘The age structure of the natural Zoysia japonica clonal population at QipanMountain in Huishan Scenic Spot of Shenyang, Liaoning Province, China was studied using themorphological method in 2003 and 2004. The dynamics of leaves were recorded and the dynamics oftiller and rhizome in the growing season were observed. The results indicated that the rhizomesformed in different years changed in color and rigidity. Its internodes produced in autumn becameshorter. The number of naked nodes changed with the tiller age. Rhizome and tiller characters wereused as a foundation for judging the ages of modules in this study. The longevity of tiller andrhizome was 3 years at most. At the beginning of the growing season, 2-year-old tillers and rhizomespredominated. Then 1-year-old tillers and rhizomes increased rapidly and became dominant in July.The proportion of buds to tillers on quantity was stable at about 30% in the mid-phase of thegrowing season and rose to about 50% in autumn. The seasonal dynamics of tiller, rhizome and bud wasvery important to guarantee the sustained existence of the Zoysia japonica population. The turnoverof modules was the mechanism of sustaining the rejuvenation of the Zoysiajaponica clonalpopulation.
文摘ARC and ND colony were obtained by rearing the whitebacked planthopper (WBPH), Sogatella furcifera (Horvath), exclusively on ARC10239 (ARC, carrying resistance gene Wbph2) and N'Diang Marie (ND, carrying resistance gene Wbph5) till 15 generations. Taichung Native 1 (TN1) and Rathu Heenati (RHT) served as susceptible and resistant check, respectively. The results of electronic recording revealed that duration of salivation and X-waveform of the two colonies on their corresponding hosts was short while the duration of phloem ingestion was long. The amount of honeydew excreted by ARC and ND colony did not differ on their corresponding host varieties from TN1 and was much higher than that of RHT. The number of eggs laid on their host varieties and TN1 were significantly higher than that on RHT. No distinct change was observed for these two colonies in term of percentage of developed eggs. The nymph survival rate of ND colony on its selection host was 45.0%, significantly different from that on TNI(71.4%) and RHT(21.0%), while that of ARC colony was 68.3%, not significantly different from that on TN1 (77.5%), but much higher than that on RHT(22.6%). The nymphal development duration of these two colonies on the corresponding hosts was not different from that on TN1, but significantly shorter than that on RHT. In brief, these two colonies had almost adapted to their corresponding host varieties based on feeding and oviposition, but the nymphal survival rate of ND colony was still low.
