Polar auxin transport (PAT) is a major determinant of plant morphology and internal anatomy with important roles in vascular patterning, tropic growth responses, apical dominance and phyllotactic arrangement. Woody plants present a highly complex system of vascular development in which isolated bundles of xylem and phloem gradually unite to form concentric rings of conductive tissue. We generat...

Background Can Arabidopsis research contribute to our understanding about wood development? Does the function of vascular cambium in a herbaceous weed resemble that of a tree? Despite its diminutive size as compared to a tree, Arabidopsis still displays cambial driven secondary thickening in several organs, including the hypocotyl. Hypocotyl is a good model organ for wood development studies, a...

BACKGROUND AND AIMS One of the most extreme manifestations of parasitism is found in the genus Cytinus, a holoparasite whose vegetative body is reduced to an endophytic system living within its host root. There are two species of Cytinus in the Mediterranean, C. hypocistis and C. ruber, which parasitize various genera of Cistaceae, one of the most characteristic families of the Mediterranean sc...

BACKGROUND The potential transfer of engineered nanoparticles (ENPs) from plants into the food chain has raised widespread concerns. In order to investigate the effects of ENPs on plants, young cabbage plants (Brassica oleracea) were exposed to a hydroponic system containing yttrium oxide (yttria) ENPs. The objective of this study was to reveal the impacts of NPs on plants by using K-edge subtr...

one of the barriers during whey filtration using uf membrane is the fouling phenomenon of the membrane, which is caused by whey proteins. in this work, the uf membranes were prepared using polysufone (psf), dimethyl formamide (dmf), 1 wt.% poly vinyl pyrrolidone (pvp) and different concentrations of licl via phase inversion induced by immersion precipitation. the prepared membranes were charact...

In this article 4 we introduce a blockage-detection method, which manages to detect a large set of blockage positions in pawn endgames, with practically no additional overhead. By examining different elements of the pawn structure, the method checks whether the Pawns form a blockage which prevents the King from penetrating into the opponent’s camp. It then checks several criteria to find out wh...

One adaptation of plants to cope with drought or frost stress is to develop wood that is able to withstand the formation and distribution of air bubbles (emboli) in its water conducting xylem cells under negative pressure. The ultrastructure of interconduit pits strongly affects drought-induced embolism resistance, but also mechanical properties of the xylem are involved. The first experimental...

Vascular occlusions are common structural modifications made by many plant species in response to pathogen infection. However, the functional role(s) of occlusions in host plant disease resistance/susceptibility remains controversial. This study focuses on vascular occlusions that form in stem secondary xylem of grapevines (Vitis vinifera) infected with Pierce's disease (PD) and the impact of o...

Pinyon–Juniper communities are found throughout the high deserts of the south-western United States, predominantly at elevations between 1500 and 2000 m (Johnston 1994). The Pinyon–Juniper habitat is semiarid, receiving c. 40 cm of yearly precipitation. The actual rainfall over a local elevational gradient, however, can vary more than twofold (West 1988). Juniper dominates in the lower, drier s...

Wood, or secondary xylem, is a water-conductive and supportive vascular tissue highly characteristic of trees. In addition to parenchymatous cells adapted for storage and transport functions, wood is mainly composed of various vertically elongated cell types. These are classified either as tracheary elements or fibers, both of which are characterized with extensive secondary cell wall thickenin...