We tested the hypothesis that the effective oncotic force that opposes fluid filtration across the microvessel wall is the local oncotic pressure difference across the endothelial surface glycocalyx and not the global difference between the plasma and tissue. In single frog mesenteric microvessels perfused and superfused with solutions containing 50 mg/ml albumin, the effective oncotic pressure exerted across the microvessel wall was not significantly different from that measured when the perfusate alone contained albumin at 50 mg/ml. Measurements were made during transient and steady-state filtration at capillary pressures between 10 and 35 cmH(2)O. A cellular-level model of coupled water and solute flows in the interendothelial cleft showed water flux through small breaks in the junctional strand limited back diffusion of albumin into the protected space on the tissue side of the glycocalyx. Thus oncotic forces opposing filtration are larger than those estimated from blood-to-tissue protein concentration differences, and transcapillary fluid flux is smaller than estimated from global differences in oncotic and hydrostatic pressures.

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Plants interact with their environment and they often flower earlier under stress conditions, but how such stress-induced flowering is regulated remains poorly understood. Here evidence is presented that the miR169 family plays a key role in stress-induced flowering in plants. The microRNA (miRNA) miR169 family members are up-regulated in Arabidopsis, maize, and soybean under abiotic stresses. Overexpression of miR169d in Arabidopsis results in early flowering, and overexpression of the miR169d target gene, AtNF-YA2, especially a miR169d-resistant version of AtNF-YA2, results in late flowering. The results suggest that the miR169 family regulates stress-induced flowering by repressing the AtNF-YA transcription factor, which in turn reduces the expression of FLOWERING LOCUS C (FLC), allowing for the expression of FLC target genes such as FLOWERING LOCUS T (FT) and LEAFY (LFY) to promote flowering. It was shown that the expression of genes or miRNAs involved in the other flowering pathways, namely the photoperiod (CO), ambient temperature (SVP), ageing (miR156), and gibberelin (SOC1) pathways, was not affected in miR169d-overexpressing plants, suggesting that stress-induced early flowering is a novel signalling pathway mediated by miR169.

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Chrysanthemum is one of the most important and popular ornamentals over the world. Breeding of new pedigrees depends mainly on conventional crossing. Chrysanthemum genetic resources were categorized into three groups. Here we introduce the wild species and related genera of Chrysanthemum in order to extend the genetic resources that can be used for genetic improvement of chrysanthemums by hybridization. In the genus Chrysanthemum and closely related genera, there are many wild species that are able to cross successfully with modern chrysanthemums. These represent important genetic resources for introducing new characters into florist's chrysanthemums. The genus Chrysanthemum consists of more than 40 species distributed mainly in East Asia. More than 20 species of Chrysanthemum are native to China. Unfortunately, little of this information has been published in western languages. In this paper, we also provide an overall review of the basic information of the wild species of we have collected in China in order to understand and exploit those genetic resources much better. We have collected about 17 wild species and studied their useful characters in the past several years. These species include C. oreastrum (Hance)

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