The relationship between the water relations of six olive cultivars exposed to different soil temperatures (14 ± 0.1, 9.9 ± 0.1 and 5.8 ± 0.2°C) and their inherent frost resistance (as determined by two different methods) was investigated. Soil chilling was achieved by introducing pots of olive plants into water baths. The water relations of these plants were compared to those of plants kept un...

The mechanism of carbon transport in Zea mays leaves was investigated using carbon 11 which is a short lived (half-life 20.4 min) positronemitting isotope. The gamma radiation produced on annihilation allows in vivo or nondestructive measurement of the isotope and the short half-life allows many measurements of translocation to be made on the same leaf within the same day.Carbon 11 produced by ...

Tobacco plants (Nicotiana rustica L.) pre-exposed to leaf dehydration, mineral deprivation, salination, or BO(3) (3-) toxicity exhibited increased resistance to subzero temperature and to reduced oxygen in the root medium. The stressed plants all showed an elevated content of leaf abscisic acid. Upon transfer of mineral deprived and salinated plants to prestress conditions, a decline in leaf ab...

By using a thermogravimetric analyser under argon atmosphere, the pyrolysis process and the kinetic model of phoenix tree residues (the little stem, middle stem, and leaf) at a 30 °C min−1 heating rate and the phoenix tree mix at three different heating rates (10 °C min−1, 30 °C min−1, and 50 °C min−1) were examined. The catalyst and the co-pyrolysis samples were at a 30 °C min−1 heating rate. ...

Plants have evolved and adapted to different environments. Dwarfism is an adaptive trait of plants that helps them avoid high-energy costs under unfavourable conditions. The role of gibberellin (GA) in plant development has been well established. Several plant dehydration-responsive element-binding proteins (DREBs) have been identified and reported to be induced under abiotic and biotic stress ...

As plant tissues dehydrate, water transport efficiency declines, a process typically attributed to air obstruction (embolism) in the xylem. Trifiló et al. (pages 5029– 5039) dissect leaf hydraulic vulnerability and show that both xylem and living tissues may be important. If confirmed and clarified, an important role for outside-xylem hydraulic decline will change our understanding of how plant...

In order to study the impact of a decline of leaf internal CO(2) molar ratio on nitrate reductase (NR) and sucrose-phosphate synthase (SPS) activities, leaves of wheat (Triticum durum) were submitted to different treatments: slow or rapid dehydration and decline in ambient CO(2) concentration and abscisic acid (ABA) supply. In agreement with the literature, NR activity of slowly dehydrated leav...

Across plant species, leaves vary enormously in their size and their venation architecture, of which one major function is to replace water lost to transpiration. The leaf hydraulic conductance (K(leaf)) represents the capacity of the transport system to deliver water, allowing stomata to remain open for photosynthesis. Previous studies showed that K(leaf) relates to vein density (vein length p...