α-Domain of human metallothionein IA can bind to metals in transgenic tobacco plants

We have introduced a genetically marked Dissociation transposable element (Ds ^HPT ) into tomato (Lycopersicon esculentum) by Agrobacterium tumefaciens-mediated transformation. Probes for the flanking regions of the T-DNA and transposed Ds ^HPT elements were obtained with the inverse polymerase chain reaction (IPCR) technique and used in RFLP linkage analyses. The RFLP map location of 11 T-DNAs carrying Ds ^HPT was determined. The T-DNAs are distributed on 7 of the 12 tomato chromosomes. To explore the feasibility of gene tagging strategies in tomato using Ds ^HPT , we examined the genomic distribution of Ds ^HPT receptor sites relative to the location of two different, but very closely linked, T-DNA insertion sites. After crosses with plants expressing Ac transposase, the hygromycin phosphotransferase (HPT) marker on the Ds element and the excision markers β-glucuronidase (GUS) and Basta resistance (BAR) facilitated the identification of plants bearing germinally transposed Ds ^HPT elements. RFLP mapping of 21 transposed Ds ^HPT elements originating from the two different T-DNA insertions revealed distinct patterns of reintegration sites.     

A Preliminary Study of Late Triassic Plants from Qinghe of Yanbian District,Sichuan Province

This paper deals with fossil plants 144 species belong to 46 genera col- lected from Qinghe of Yanbian District, Siehuan Provinee. In this paper 5 new species are described, i.e.: Marattia sichuanensis, Drepanozamites multipartitus, Podozamites sichuanensis, Pityostrobus yanbianensis and Scoresbya entegra. The dominant group of the Qinghe flora is Cycadophyta (9 genera and 38 species) Filicopsida is also a large group (12 genera and 32 species) in this flora, of which Dipteridaceae, Angiopteridaceae, Marattiaceae and Osmundaceae are rieher in species than others. Pteridospermae is fairly numerous in this flora. Ginkgoales and Coniferales are very rich. The dominance of Podozamites forms the most conspicuous feature of this flora. Based on the characters of this flora, it closely resembles Yipinglang flora of Yunnan, Xujiahe flora of Sichuan, Tonkin flora of Vietnam, Nariwa flora of Japan and East Greenland flora, but is younger than the Daqiaodi flora found in Baoding of Si- chuan. The age of the flora is assigned to the middle Keuper-Rhaetic stage of the late Triassic. The climate of that time was tropic-subtropic in nature.