Flooding tolerance of Carex species in relation to field distribution and aerenchyma formation.

The flooding tolerance of Carex species was studied in relation to their field distribution and their capacity to form root aerenchyma under controlled conditions. In an alpine meadow, six Carex species were selected which were distributed in a clear zonation correlating with water content of the soil. Carex sempervirens and C.

The role of oxygen in submergence-induced petiole elongation in Rumex palustris: in situ measurements of oxygen in petioles of intact plants using micro-electrodes.

In a study on the mechanism of stimulated petiole elongation in submerged plants, oxygen concentrations in petioles of the flood-tolerant plant Rumex palustris were measured with micro-electrodes. Short-term submergence lowered petiole partial oxygen pressure to c. 19 kPa whereas prolonged submergence under continuous illumination depressed oxygen levels to c.

The role of ethylene and darkness in accelerated shoot elongation of Ammophila breviligulata upon sand burial.

The impact of elevated ethylene concentrations and darkness on the growth and development of shoot organs of Ammophila breviligulata was investigated under experimental conditions in a complete two-way design. The results were compared with data of partially sand buried plants. Enhanced ethylene concentrations and sand burial stimulated the formation of new stem nodes, a prerequisite for burial-induced shoot elongation.

Ethylene Sensitivity and Response Sensor Expression in Petioles of Rumex Species at Low O2 and High CO2 Concentrations.

Rumex palustris, a flooding-tolerant plant, elongates its petioles in response to complete submergence. This response can be partly mimicked by enhanced ethylene levels and low O2 concentrations. High levels of CO2 do not markedly affect petiole elongation in R.

An Ethylene-Mediated Increase in Sensitivity to Auxin Induces Adventitious Root Formation in Flooded Rumex palustris Sm.

The hormonal regulation of adventitious root formation induced by flooding of the root system was investigated in the wetland species Rumex palustris Sm. Adventitious root development at the base of the shoot is an important adaptation to flooded conditions and takes place soon after the onset of flooding. Decreases in either endogenous auxin or ethylene concentrations induced by application of inhibitors of either auxin transport or ethylene biosynthesis reduced the number of adventitious roots formed by flooded plants, suggesting an involvement of these hormones in the rooting process.

Ethylene Biosynthesis and Accumulation under Drained and Submerged Conditions (A Comparative Study of Two Rumex Species).

A model is presented of the regulation of ethylene biosynthesis in relation to submergence and flooding resistance. It is based on time-course measurements of ethylene production, ethylene accumulation, and concentrations of free and conjugated 1-aminocyclo-propane-1-carboxylic acid (ACC) in submerged and drained flooding-resistant Rumex palustris Sm. and flooding-sensitive Rumex acetosella L.

Potamogeton pectinatus Is Constitutively Incapable of Synthesizing Ethylene and Lacks 1-Aminocyclopropane-1-Carboxylic Acid Oxidase.

A highly sensitive laser-driven photoacoustic detector responsive to [less than or equal to]2.1 nmol m-3 ethylene (50 parts per trillion [v/v]) was used for ethylene analysis. Dark-grown plants of Potamogeton pectinatus L.

Investigation of Local Ethylene Emission from Intact Cherry Tomatoes by Means of Photothermal Deflection and Photoacoustic Detection.

The function of the coronet region of the cherry tomato (Lycopersicon esculentum Cherry) as the main emission channel for ethylene was investigated. Ethylene was measured employing two laser-based detection systems, the photothermal deflection instrument and the photoacoustic detection setup. It is possible to detect minimum ethylene concentrations of 1 nL L-1 locally and rapidly with the first instrument and concentrations of 6 pL L-1 in a continuous flow system with the second setup.

Root porosities and radial oxygen losses of Rumex and Plantago species as influenced by soil pore diameter and soil aeration.

The effects of hypoxia in ballotini and quartz sand with respectively large and small soil pore diameters on root porosity was studied for Rumex palustris Sra., Rumex acetosa L. and Plantago major L.

Submergence-Induced Ethylene Synthesis, Entrapment, and Growth in Two Plant Species with Contrasting Flooding Resistances.

Submergence-induced ethylene synthesis and entrapment were studied in two contrasting Rumex species, one flood-resistant (Rumex palustris) and the other flood-sensitive (Rumex acetosa). The application of a photoacoustic method to determine internal ethylene concentrations in submerged plants is discussed. A comparison with an older technique (vacuum extraction) is described.

Flooding resistance and shoot elongation in relation to developmental stage and environmental conditions in Rumex maritimus L. and Rumex palustris Sm.

The flooding resistance of Rumex maritimus L. and Rumex palustris Sm., two species from frequently flooded areas of river forelands, was studied in two large-scale outdoor experiments.

Plasticity in life-history traits of Plantago major L. ssp. pleiosperma Pilger.

Plasticity in life-history characteristics was investigated in three populations of Plantago major L. ssp. pleiosperma (Pilger), a self-compatible, wind pollinated species with a high self-fertilization rate.