Attachment of conidia on leaves is a critical first step in the life cycle of aquatic hyphomycetes in streams. In a first series of microcosm experiments, attachment success of three common aquatic hyphomycete species differing in conidial shape (compact, filiform and tetraradiate) was determined on two leaf species, black alder and downy oak. Fungal species identity and leaf surface structure ...

Ranunculus trichophyllus is an amphibious plant that produces thin and cylindrical leaves if grown under water but thick and broad leaves if grown on land. We found that such heterophylly is widely controlled by two plant hormones, abscisic acid (ABA) and ethylene, which control terrestrial and aquatic leaf development respectively. Aquatic leaves produced higher levels of ethylene but lower le...

The lengths of fossil leaves of Nothofagus cunninghamii, and of closely related fossil species from sediments older than the Middle Pleistocene showed greater variation than fossil leaves from younger sediments and extant leaves from modern sediment samples and forest floor litter. Leaf sizes of samples of the other two extant evergreen species of Nothofagus subgenus Lophozonia, N. moorei and N...

The vascular tissues of plants are organized as strands of aligned cells in all the main organs. They differentiate from narrow, interconnected provascular cells, which are visible in the early leaf primordia of Arabidopsis thaliana in the top left panel. Plant hormones in the auxin class can induce the formation of additional vascular strands. Because auxins are produced in young leaves and th...

Panicum maximum Jacq. 'Mombaça' (C4) was grown in field conditions with sufficient water and nutrients to examine the effects of warming and elevated CO2 concentrations during the winter. Plants were exposed to either the ambient temperature and regular atmospheric CO2 (Control); elevated CO2 (600 ppm, eC); canopy warming (+2°C above regular canopy temperature, eT); or elevated CO2 and canopy w...

The partitioning of carbon in intact, mature cotton (Gossypium hirsutum L.) leaves was examined by steady-state (14)CO(2) labeling. Plants were exposed to dark periods of varying lengths, followed by similar illuminated labeling periods. These treatments produced leaves with a range of starch and soluble sugar contents, carbon exchange, and carbon export rates. Export during the illuminated per...

Mancera et al., 1999). The reappearance of chlorophyll (Chl ) correlated with the reappearance of the Chl biosynSingle senescent leaves attached to decapitated thesis enzyme, NADPH-protochlorophyllide oxidoreducshoots of Nicotiana rustica L. regreened, especially tase (POR). Development of functional thylakoid when treated with cytokinin. Regreening caused an membranes during regreening was ind...

We measured variations in leaf dark respiration rate (Rd) and leaf nitrogen (N) across species, canopy light environment, and elevation for 18 co-occurring deciduous hardwood species in the southern Appalachian mountains of western North Carolina. Our overall objective was to estimate leaf respiration rates under typical conditions and to determine how they varied within and among species. Mean...

During their development, leaves progress through a highly controlled yet flexible developmental program. Transcription factors from the CIN-TCP family affect leaf shape by regulating the timing of leaf maturation. Characterization of mutants in the tomato (Solanum lycopersicum) CIN-TCP gene LANCEOLATE (LA) led us to hypothesize that a threshold LA-like activity promotes leaf differentiation. H...

It is a classical result that an unrooted tree T having positive real-valued edge lengths and no vertices of degree two can be reconstructed from the induced distance between each pair of leaves. Moreover, if each non-leaf vertex of T has degree 3 then the number of distance values required is linear in the number of leaves. A canonical candidate for such a set of pairs of leaves in T is the fo...