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Lipochitin oligosaccharides (LCOs) are signaling molecules required by ecologically and agronomically important bacteria and fungi to establish symbioses with diverse land plants. In plants, oligo-chitins and LCOs can differentially interact with different lysin motif (LysM) receptors and affect innate immunity responses or symbiosis-related pathways. In animals, oligo-chitins also induce innate immunity and other physiological responses but LCO recognition has not been demonstrated. Here LCO and LCO-like compounds are shown to be biologically active in mammals in a structure dependent way through the modulation of angiogenesis, a tightly-regulated process involving the induction and growth of new blood vessels from existing vessels. The testing of 24 LCO, LCO-like or oligo-chitin compounds resulted in structure-dependent effects on angiogenesis in vitro leading to promotion, or inhibition or nil effects. Like plants, the mammalian LCO biological activity depended upon the presence and type of terminal substitutions. Un-substituted oligo-chitins of similar chain lengths were unable to modulate angiogenesis indicating that mammalian cells, like plant cells, can distinguish between LCOs and un-substituted oligo-chitins. The cellular mode-of-action of the biologically active LCOs in mammals was determined. The stimulation or inhibition of endothelial cell adhesion to vitronectin or fibronectin correlated with their pro- or anti-angiogenic activity. Importantly, novel and more easily synthesised LCO-like disaccharide molecules were also biologically active and de-acetylated chitobiose was shown to be the primary structural basis of recognition. Given this, simpler chitin disaccharides derivatives based on the structure of biologically active LCOs were synthesised and purified and these showed biological activity in mammalian cells. Since important chronic disease states are linked to either insufficient or excessive angiogenesis, LCO and LCO-like molecules may have the potential to be a new, carbohydrate-based class of therapeutics for modulating angiogenesis. [ABSTRACT FROM AUTHOR]

Efficient and reproducible selection of transgenic plant cells is an essential component of a successful transformation and regeneration. Usually antibiotic resistant genes are used as selectable markers. In view of biosafety considerations, attempts have been made to substitute such genes with ones that are less harmful, such as herbicide resistance. Glyphosate is a non-selective, broad-spectrum herbicide that inhibits 5-enolpyruvylshikimate- 3-phosphate synthase, a key enzyme in the aromatic amino acid biosynthetic pathway in microorganisms and plants. In this project, a new binary vector (pSA101) hauling a glyphosate tolerant construct as a selectable marker for Agrobacterium-mediated transformation of plant cells was constructed. Precise attachment of different fragments of the synthetic construct was carried out by the SOEing PCR. This construct contains the first intron of Hsp70 from maize, a chloroplastic transient peptide of Rubico from Brassica napus and a bacterial glyphosate tolerant mutated EPSPS gene. It was expressed under the control of the CaMV 35S promoter and nos terminator. Transgenic tobacco plants with increased tolerance to glyphosate were directly selected on medium containing glyphosate. Molecular analyses confirmed the correctness of gene integration and expression. The results of transformation, regeneration and selection of transgenic tobacco plants with this new vector showed that is a usable and safer plasmid than those carrying the antibiotic resistance gene as a selectable marker. [ABSTRACT FROM AUTHOR]