Highly purified amyloplasts were isolated from cultured cells of sycamore (Acer pseudoplatanus L.). Incubation of amyloplasts with [gamma-(32)P]-ATP resulted in the labeling of more than ten polypeptides. Pulsechase experiments showed the reversibility of the process with some but not all of the polypeptides. The phosphorylation reaction of one polypeptide, M(r) 100, was shown to be calcium dep...

Xyloglucan, isolated from the soluble extracellular polysaccharides of suspension-cultured sycamore (Acer pseudoplatanus) cells, was digested with an endo-beta-1,4-glucanase purified from the culture fluid of Trichoderma viride. A nonasaccharide-rich Bio-Gel P-2 fraction of this digest inhibited 2,4-dichlorophenoxyacetic-acid-stimulated elongation of etiolated pea stem segments. The inhibitory ...

A phytostat to mass culture higher plant cells in liquid medium is described. This apparatus allowed the culture in batch, turbidostat and chemostat of 20 liters of cells. Automatic control of cell suspension growth was based on culture turbidity. Changes with time of certain cell characteristics, particularly cell respiration and phospholipid content, indicated that the test time to harvest la...

Anthracnose is one of the most common and important foliage diseases of shade trees in Iowa. Symptoms of anthracnose are often referred to as “leaf blights” or “leaf spots” and are most serious on sycamore, ash, maple, white and bur oak, and walnut. Linden, hickory, elm, red and black oak, and other deciduous trees also are susceptible, although anthracnose is less common and damaging on these ...

There have been several recent electron-microscopic studies on the development of the vascular cambium (Bouck & Cronshaw, 1965; Buvat, 1963, 1964; Cronshaw, 1967; Esau & Cheadle, 1965; Srivastava & O'Brien, 1966; Northcote & Wooding, 1966; Wooding & Northcote, 1964; Wooding, 1966). The organelles involved have been tentatively identified and functions for each suggested. The present report is o...

Bacterial leaf scorch is caused by Xylella fastidiosa Wells et al. The pathogen causes chronic leaf scorch and decline in elm, oak, sycamore, and maple. X. fastidiosa has a wide host range and is responsible for many other serious diseases including Pierce's disease of grape, phony disease of peach, and citrus variegated chlorosis. Its role in shade tree disorders has only recently been recogni...