ABSTRACT
cDNA and genomic clones encoding Brassica napus non-specific lipid transfer proteins (LTP) were isolated and sequenced. The encoded amino acid sequences were very similar to those reported previously for LTPs from B. napus and other species. Sequence information indicates that B. napus contains an LTP gene family. The 5'-flanking region of one gene, designated BnLTP, was fused to GUS and the fusion introduced into Arabidopsis. LTP transcripts and BnLTP-Gus expression were present predominantly in the epidermis of leaf and stem, consistent with the hypothesised function of LTPs in the deposition of cuticular or epicuticular waxes. However, GUS activity was detected in other tissues, including lateral root initials, anthers, stigmas and vascular tissues, which may suggest additional functions. LTP transcript levels in B. napus and Arabidopsis and BnLTP-GUS expression in transgenic Arabidopsis were stimulated by blue and red light but not UV-B. BnLTP promoter activity was also stimulated upon viral infection, at a time when the virus had spread systemically. No increase in expression was observed in response to cold or wounding.
Subject(s)
Arabidopsis/genetics , Brassica/genetics , Carrier Proteins/genetics , Light , Promoter Regions, Genetic/genetics , Amino Acid Sequence , Antigens, Plant , Arabidopsis/virology , Brassica/chemistry , Carrier Proteins/metabolism , Caulimovirus/growth & development , Cold Temperature , DNA, Complementary/chemistry , DNA, Complementary/genetics , DNA, Plant/chemistry , DNA, Plant/genetics , Gene Expression Regulation, Plant/radiation effects , Glucuronidase/analysis , Glucuronidase/genetics , Histocytochemistry , In Situ Hybridization , Molecular Sequence Data , Plant Proteins , Plants, Genetically Modified , RNA, Plant/genetics , RNA, Plant/metabolism , Recombinant Fusion Proteins/genetics , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Tissue DistributionABSTRACT
We have isolated a gene and cDNA from Brassica napus encoding a hybrid-proline-rich protein. The putative protein is modular in structure. The N-terminal domain has properties of a signal peptide which would direct the protein into the ER. Amino acids 27 to 287 comprise three domains which contain high levels of proline and several other amino acids common in proline-rich cell wall proteins. These domains are characterised by repeating amino acid motifs. The C-terminal domain (amino acids 288 to 376) contains three putative membrane-spanning regions and shows a high degree of amino acid similarity to known hybrid-proline-rich proteins from several species. It is likely that the protein is secreted from the cell, located in the cell wall and anchored in the plasma membrane via the C-terminal domain. Transcripts encoding this protein are induced in leaf tissue within 8 h of cold treatment and decrease rapidly when plants are returned to normal temperatures. The transcripts are not induced by heat shock, dehydration, exogenous ABA or wounding, whereas transcripts of a control B. napus gene are induced by dehydration and ABA. The possible function of this protein in cold tolerance is discussed.
Subject(s)
Brassica/genetics , Cold Temperature , Gene Expression Regulation, Plant/physiology , Heat-Shock Proteins/genetics , Membrane Proteins/genetics , Plant Proteins , RNA, Messenger/analysis , RNA, Plant/analysis , Abscisic Acid/pharmacology , Amino Acid Sequence , Base Sequence , Cell Membrane , Cell Wall , Cloning, Molecular , DNA, Complementary/genetics , DNA, Plant/genetics , Gene Expression Regulation, Plant/drug effects , Genes, Plant/genetics , Heat-Shock Proteins/chemistry , Membrane Proteins/chemistry , Molecular Sequence Data , Protein Sorting Signals/genetics , Sequence Analysis, DNA , Sequence Homology, Amino AcidABSTRACT
Se considera actualmente al histiocitoma fibroso maligno como uno de los sarcomas de partes blandas mas frecuentes del adulto. Se presentan como comunicacion preliminar, tres observaciones clinicas de esta variedad histologica no referida en nuestro medio. En una breve revision bibliografica se enumeran sus caracteres anatomo clinicos y terapeuticos mas salientes, tratandose de un tumor predominantemente pleomorfico, con un patron histologico caracteristico, y cuya histogenesis es aun hoy, controvertida
