(Leaf anatomy of two Anemia Sw. species (Schizaeaceae-Pteridophyte) from a rocky outcrop in Niterói, Rio de Janeiro, Brazil). The ferns Anemia tomentosa (Sav.) Sw. var. anthriscifolia (Schrad.) Mickel and Anemia villosa Humb. & Bonpl. ex Willd. are widely associated with vegetation islands on rocky outcrops in Rio de Janeiro. Both species are desiccation tolerant. The leaf anatomy of these spec...

BACKGROUND AND AIMS Litter is a key factor in structuring plant populations, through positive or negative interactions. The litter layer forms a mechanical barrier that is often strongly selective against individuals lacking hypocotyle plasticity. Litter composition also interacts with plant growth by providing beneficial nutrients or, inversely, by allowing harmful allelopathic leaching. As co...

Apterous populations of Chaitophorous populicola Thomas (Homoptera: Aphididae) appear to track Eastern cottonwood (Populus deltoides Bartr.) leaf development. Few aphids occur onmature leaves.Marked individual aphids on leaves of different developmental stageswereobserved through a period of new leaf initiation. Nymph and adult C. populicola frequently track leaf development bymoving up to youn...

Nitrate reductase was found in leaves of apricot Prunus armeniaca, sour cherry P. cerasus, sweet cherry P. avium, and plum P. domestica, but not in peach P. persica, from trees grown in sand culture receiving a nitrate containing nutrient solution. Nitrate was found in the leaves of all species. Nitrate and nitrate reductase were found in leaves of field-grown apricot, sour cherry, and plum tre...

The leaves of quaking aspen (Populus tremuloides Michx.) have a flattened petiole that allows them to quake (oscillate and roll) under low wind velocities. It was hypothesized that this adaptation might enable the plant to respond to windy conditions that would increase transpirational losses. No effects of wind with or without leaf quaking on stomatal resistance were observed under controlled ...

Abstract Intraspecific trait variability (ITV) can be considerably high and reveal plant local adaptation. The aim of this study is to investigate ITV leaf traits (including petioles) in a rooted floating-leaved macrophyte ( Nuphar lutea ) at the scale. We expected see changes resource-use strategies relation water sediment properties. 96 leaves were sampled hyper-eutrophic shallow lake central...

The expression of 28 high light (HL)-responsive genes of Arabidopsis was analysed in response to environmental and physiological factors known to influence the expression of the HL-responsive gene, ASCORBATE PEROXIDASE2 (APX2). Most (81%) of the HL-responsive genes, including APX2, required photosynthetic electron transport for their expression, and were responsive to abscisic acid (ABA; 68%), ...

Water-soluble glycopeptides isolated from cultures of Ceratocystis ulmi have been reported to be toxins involved in Dutch elm disease. The influence of the glycopeptides on the water relations of Ulmus americana seedlings was tested by placing cut stems in glycopeptide preparations. After 4 hours in 200 micrograms per milliliter toxin the stem conductance of the seedlings was reduced by 79% and...