In barley (Hordeum vulgare L.) the unit of inflorescence is the spikelet, which bears a fertile bract, the lemma, and the floret consisting of palea, two lodicules, three stamens and the pistil. The Hooded mutation causes the appearance of an extra flower of inverse polarity on the lemma. This phenotype is governed by the single dominant genetic locus K3. Here we show that the homeobox gene Knox3 represents this locus. Ectopic Knox3 gene expression in the primordium of the extra floret is caused by a 305-base pair duplication in intron 4, and phenocopies of the mutation are obtained in the heterologous tobacco system by Knox3 overexpression. It is concluded that homeotic genes of the Knox gene family are involved in floral evocation. Furthermore, the study of polarity of reproductive organs in K and related mutants can now focus on homeobox genes.
The new water-soluble ruthenium(II) chiral complexes [RuCpX(L)(L')](n+) (X = Cl, I. L = PPh3; L' = PTA, mPTA; L = L' = PTA, mPTA) (PTA = 1,3,5-triaza-7-phosphaadamantane; mPTA = N-methyl-1,3,5-triaza-7-phosphaadamantane) have been synthesized and characterized by NMR and IR spectroscopy and elemental analysis. The salt mPTA(OSO2CF3) was also prepared and fully characterized by spectroscopic techniques. X-ray crystal structures of [RuClCp(PPh3)(PTA)] (2), [RuCpI(PPh3)(PTA)] (3), and [RuCpI(mPTA)(PPh3)](OSO2CF3) (9) have been determined. The binding properties toward DNA of the new hydrosoluble complexes have been studied using the mobility shift assay. The ruthenium chloride complexes interact with DNA depending on the hydrosoluble phosphine bonded to the metal, while the corresponding compounds with iodide, [RuCpI(PTA)2] (1), [RuCpI(PPh3)(PTA)] (3), [RuCpI(mPTA)2](OSO2CF3)2 (6), and [RuCpI(mPTA)(PPh3)](OSO2CF3) (9), do not bind to DNA.
a b s t r a c tThe oceanic islands of Macaronesia provide an ideal temporal and spatial context to test hypotheses of plant evolution using a novel set of phylogenetic markers, D 6 -desaturase sequences. In contrast to the limited resolution of standard molecular markers (nrDNA and plastid sequences), the D 6 -desaturase sequence phylogeny of Echium unequivocally reconstructs its active colonization across islands and archipelagos (Madeira, the Canary Islands, and Cape Verde), as well as its subsequent geographical and ecological speciation. Molecular-clock estimates using penalized likelihood and Bayesian inference reveal two radiation processes coincident with two dramatic climatic changes recorded in the region: the advent of the cold Canarian sea current (ca. 4 Ma) and the establishment of a strong seasonality in the Pleistocene (1.8 Ma). Though Echium had available all the diversity of present-day Macaronesian environments (xeric and mesic scrub, laurisilva, pine forest, and subalpine habitats) in the Miocene, evolutionary divergence appears to have been triggered by an extension of fluctuating xeric and mesic habitats with the advent of Pliocene conditions. These Echium radiations not only fulfill traditional predictions of adaptive radiation (i.e., common ancestry, rapid speciation, and phenotype-environment correlation), but also, uniquely among Macaronesian species, trait utility of woodiness. A Pliocene transition from annuality to a bush or tree-like condition occurred in early Echium lineages. Maintenance of woodiness in major lineages, and reversal to an herbaceous condition by three independent events, is reported for the first time in plants of oceanic islands.
A cDNA clone, STMADS11, encoding a new MADS-box protein was isolated from Solanum tuberosum L. (potato). Expression of STMADS11 was found in all vegetative organs of the plant, but not in floral tissues. The expression was also detected in all developmental stages, from tuber sprouts to mature plants, reaching a maximum in well-developed organs. However, the level of STMADS11 mRNA was low in tissues such as resting tuber or sprouts developed in the cold, where the metabolic activity is reduced. "In situ" hybridizations performed on leaf and stem sections showed that the STMADS11 transcript is mainly associated with vascular bundles. Cladistic analysis arising from amino acid sequence comparison revealed that STMADS11 shows the highest similarity to STMADS16, another vegetative MADS-box gene from potato, and to the previously reported "orphan" genes AGL15 and AGL17 from Arabidopsis thaliana. Possible implications of these data in relation to STMADS11 function are discussed.
Three novel gold nanoparticles containing multiple long, flexible linkers decorated with lactose, β-cyclodextrin, and both simultaneously have been prepared. The interaction of such nanoparticles with β-d-galactose-recognizing lectins peanut agglutinin (PNA) and human galectin-3 (Gal-3) was demonstrated by UV-vis studies. Gal-3 is well-known to be overexpressed in several human tumors and can act as a biorecognizable target. This technique also allowed us to estimate their loading capability toward the anticancer drug methotrexate (MTX). Both results make these glyconanoparticles potential site-specific delivery systems for anticancer drugs.
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