Two critical requirements of the cohesion mechanism of water ascent are (1) sufficient cohesive strength of water and (2) existence of tensions (i.e., pressures below zero) and tension gradients in stems of transpiring trees.
Many larvae bore into solid wood of living or dead trees and stumps; some feed on or in roots or in stems of semiwoody plants; and others feed in seeds, pods, grain, meal, fruits, nuts, and other parts of plants; some are hidden inside the plants.
Members of one group of chrysomelid larvae (Sagrinae) bore in stems of leguminous vines, causing gall-like swellings; others (Donaciinae) feed on and in the stems of freshwater plants, often below the water level, or hide (Cassidinae) in unopened parts of monocot plants such as palms, grasses, bamboos, and gingers; still others (Galerucinae) may feed on both roots and leaves or act as leaf miners.
Fig. 2 Timing and dynamics of cambial activity and xylogenesis in stems of Cedrus libani during 2013.
Other salts had the same effect, and it also happened in stems of 18 other angiosperms, five conifers, and three ferns.
This study investigated cambial activity and xylogenesis in stems of C. libani along an altitudinal gradient in the Taurus Mts during the growing season of 2013.
The microarray analysis for differentially expressed transcripts in stems of grain and sweet sorghum with a sugarcane genechip was previously described (Calviño et al. 2008).
Microcores were collected fortnightly in the growing season of 2013 in order to study temporal dynamics of cambial activity and xylogenesis in stems of C. libani at different altitudes in the Taurus Mountains (1000 – 2000 m a.s.l).l
The xylem in stems of C. libani showed differences in onset, duration and end of cambial activity and xylogenesis as well as growth rates with respect to climate and site conditions.
The savanna species had more xylem vessels per mm2 and these vessels were narrower than those observed in stems of the forest species, resulting in a low vulnerability to cavitation (lvul) estimated for both species.
ROS accumulation in stems of susceptible cv.
