A developmentally retarded mutant (drm1) was identified from ethyl methanesulfonate (EMS)-mutagenized M2 seedsin Columbia (Col-0) genetic background. The drm1 flowers 109 d after sowing, with a whole life cycle of abo...A developmentally retarded mutant (drm1) was identified from ethyl methanesulfonate (EMS)-mutagenized M2 seedsin Columbia (Col-0) genetic background. The drm1 flowers 109 d after sowing, with a whole life cycle of about 160 d.It also shows a pleiotropic phenotype, e.g., slow germination and lower germination rate, lower growth rate, curlingleaves and abnormal floral organs. The drm1 mutation was a single recessive nuclear mutation, which was mapped tothe bottom of chromosome 5 and located within a region of 20-30 kb around MXK3.1. There have been no mutantswith similar phenotypes reported in the literature, suggesting that DRM1 is a novel flowering promoting locus. Thefindings that the drm1 flowered lately under all photoperiod conditions and its late flowering phenotype was significantlyrestored by vernalization treatment suggest that the drm1 is a typical late flowering mutant and most likely associatedwith the autonomous flowering pathway. The conclusion was further confirmed by the revelation that the transcriptlevel of FLC was constantly upregulated in the drm1 at all the developmental phases examined, except for a very earlystage. Moreover, the transcript levels of two other important repressors, EMF and TFL1, were also upregulated in thedrm1, implying that the two repressors, along with FLC, seems to act in parallel pathways in the drm1 to regulateflowering as well as other aspects of floral development in a negatively additive way. This helps to explain why the drm1exhibits a much more severe late-flowering phenotype than most late-flowering mutants reported. It also implies that theDRM1 might act upstream of these repressors.展开更多
Whether industrialization and environmental protection can coexist has always been controversial theoretical question. On this topic, the protected watershed area of Xixia County provides an interesting case study. 91...Whether industrialization and environmental protection can coexist has always been controversial theoretical question. On this topic, the protected watershed area of Xixia County provides an interesting case study. 91% of Xixia County＇s 3,15 7 square kilometers, which belongs to Nanyang City of Henan Province and is located in the protected water source area of the country＇s South-to-North Water Diversion Project, is designated water source protection zones. Driven by the need to protect these resources, Xixia County has made remarkable achievements in the field of environmental protection. Simultaneously, the county s economy has also made significant progress. In addition to its favorable geography and natural resources, Xixia County derives its successful environmental protection practices from the following factors： first, a series of environmental protection policies issued by the central government; second, Xixia County＇s emphasis on environmental protection; and third, local businesses＇ efforts to protect the environment. Xixia＇s experience has demonstrated that environmental protection can be successfully balanced with economic development when local industrial development generates resources that contribute to favorable environmental programs.展开更多
文摘A developmentally retarded mutant (drm1) was identified from ethyl methanesulfonate (EMS)-mutagenized M2 seedsin Columbia (Col-0) genetic background. The drm1 flowers 109 d after sowing, with a whole life cycle of about 160 d.It also shows a pleiotropic phenotype, e.g., slow germination and lower germination rate, lower growth rate, curlingleaves and abnormal floral organs. The drm1 mutation was a single recessive nuclear mutation, which was mapped tothe bottom of chromosome 5 and located within a region of 20-30 kb around MXK3.1. There have been no mutantswith similar phenotypes reported in the literature, suggesting that DRM1 is a novel flowering promoting locus. Thefindings that the drm1 flowered lately under all photoperiod conditions and its late flowering phenotype was significantlyrestored by vernalization treatment suggest that the drm1 is a typical late flowering mutant and most likely associatedwith the autonomous flowering pathway. The conclusion was further confirmed by the revelation that the transcriptlevel of FLC was constantly upregulated in the drm1 at all the developmental phases examined, except for a very earlystage. Moreover, the transcript levels of two other important repressors, EMF and TFL1, were also upregulated in thedrm1, implying that the two repressors, along with FLC, seems to act in parallel pathways in the drm1 to regulateflowering as well as other aspects of floral development in a negatively additive way. This helps to explain why the drm1exhibits a much more severe late-flowering phenotype than most late-flowering mutants reported. It also implies that theDRM1 might act upstream of these repressors.
文摘Whether industrialization and environmental protection can coexist has always been controversial theoretical question. On this topic, the protected watershed area of Xixia County provides an interesting case study. 91% of Xixia County＇s 3,15 7 square kilometers, which belongs to Nanyang City of Henan Province and is located in the protected water source area of the country＇s South-to-North Water Diversion Project, is designated water source protection zones. Driven by the need to protect these resources, Xixia County has made remarkable achievements in the field of environmental protection. Simultaneously, the county s economy has also made significant progress. In addition to its favorable geography and natural resources, Xixia County derives its successful environmental protection practices from the following factors： first, a series of environmental protection policies issued by the central government; second, Xixia County＇s emphasis on environmental protection; and third, local businesses＇ efforts to protect the environment. Xixia＇s experience has demonstrated that environmental protection can be successfully balanced with economic development when local industrial development generates resources that contribute to favorable environmental programs.
