Merremia emarginata plants were treated with different plant growth regulators (PGRs): naphthyl acetic acid (NAA), phenyl acetic acid (PAA) and gibberellic acid (GA 3). To determine the role of wall stiffening enzymes in internode elongation, IAA oxidase and peroxidase in the presence of different hydrogen donors like caffeic acid, chlorogenic acid and guaiacol were assayed. The levels of total...

in this research, the effect of different concentrations of chitosan (with low molecular weight) on in vitro proliferation of grape cultivar, ’bidaneh ghermez‘, was evaluated. 30 days after establishment, elongated shoots were cultured on the half strength murashige and skoog medium supplemented with 0.5 mg/l bap, 0.1 mg/l iba and different chitosan concentrations (0, 10, 20, 40 and 80 mg/l). t...

Almost 90 years ago, Lillie reported that rapid saltatory conduction arose in an iron wire model of nerve impulse propagation when he covered the wire with insulating sections of glass tubing equivalent to myelinated internodes. This led to his suggestion of a similar mechanism explaining rapid conduction in myelinated nerve. In both their evolution and their development, myelinating axons must...

Leaf and crown characteristics were examined for 24 tree and herbaceous species of contrasting architectures from the understory of a lowland rainforest. Light-capture efficiency was estimated for the crowns of the different species with a three-dimensional geometric modeling program. Causal relationships among traits affecting light absorption at two hierarchical levels (leaf and whole crown) ...

BACKGROUND AND AIMS Plant architecture and its interaction with agronomic practices and environmental constraints are determinants of the structure of the canopy, which is involved in carbon acquisition and fruit quality development. A framework for the quantitative analysis of grapevine (Vitis vinifera) shoot architecture, based on a set of topological and geometrical parameters, was developed...

The shoot apical meristem contains a pool of undifferentiated stem cells and generates all above-ground organs of the plant. During vegetative growth, cells differentiate from the meristem to initiate leaves while the pool of meristematic cells is preserved; this balance is determined in part by genetic regulatory mechanisms. To assess vegetative meristem growth and genetic control in Zea mays,...

Partial submergence induces rapid internodal elongation in deepwater rice (Oryza sativa L., cv Habiganj Aman II). We measured in vivo extensibility, tissue tension, hydraulic conductance and osmotic potential in the region of cell elongation in the uppermost internode. The in vivo extensibility of the internode, measured by stretching of living tissue with a custom-made constant stress extensio...

Phylogenies inferred from different data matrices often conflict with each other necessitating the development of measures that quantify this incongruence. Here, we introduce novel measures that use information theory to quantify the degree of conflict or incongruence among all nontrivial bipartitions present in a set of trees. The first measure, internode certainty (IC), calculates the degree ...