Abscission is the process by which plants shed unwanted organs, either as part of a natural developmental program or in response to environmental stimuli. Studies in Arabidopsis thaliana have elucidated a number of the genetic components that regulate abscission of floral organs, including a pair of related receptor-like protein kinases, HAESA and HAESA-like 2 (HAE/HSL2) that regulate a MAP kin...

Abscission of cotyledonary leaves from cotton (Gossypium hirsutum L. cv. Stoneville 213) seedlings occurred following relief from water stress. The amount of abscission was related to the magnitude of the plant water deficit. Leaf abscission promoted by exogenous ethylene was enhanced in seedlings subjected to water stress. Treatment with ethylene (2.0 to 3.2 microliters of ethylene per liter o...

An investigation of the effect of ethylene on the fine structure of abscission cells has been prompted by the increasing amount of physiological and biochemical data on ethylene-induced abscission (cf. 1-3, 6, 7, 10-13, 18, 22). Recent investigations (14, 15, 19) have shown that certain changes occur in the fine structure of the cytoplasm and the cell wall as cell separation develops during nat...

The leaf blade of cotton (Gossypium hirsutum L. cv. Stoneville 213) was investigated as the initial site of ethylene action in abscission. Ethylene applied at 14 mul/l to intact 3-week-old plants caused abscission of the third true leaf within 3 days. However, keeping only the leaf blade of this leaf in air during ethylene treatment of the rest of the plant completely prevented its abscission f...

The relationships of fruit age, abscisic acid (ABA) concentration, ethylene evolution, and abscission rates were studied in an effort to determine why cotton (Gossypium hirsutum L., cv. Deltapine 16) fruits rarely abscise more than 15 days after anthesis. Because abscission of cotton fruits is increased by conditions that limit photosynthesis, greenhouse-grown plants with fruits of various ages...

Cytokinesis involves the formation of a cleavage furrow, followed by abscission, the cutting of the midbody channel, the final bridge between dividing cells. Recently, the midbody ring became known as central for abscission, but its regulation remains enigmatic. Here, we identify BRUCE, a 528 kDa multifunctional protein, which processes ubiquitin-conjugating activity, as a major regulator of ab...

The activity of pectin esterase and cellulase in abscission of citrus explants was studied. No relation was established between pectin esterase and abscission, while cellulase activity was markedly increased before abscission and for a certain period after excision. IAA and cycloheximide delay abscission and cellulase activity, while ethylene and, to a lesser extent, GA(3) accelerate them. Appl...

Peach orchards are usually hand-thinned at around 40–60 days after bloom, but this practice is labor-intensive and costly. Ethylene plays a key role in peach fruitlet abscission foliar applications of ethephon have been reported to be effective some cultivars induce fruit abscission. However, results inconsistent there no experiences about its application flat peaches and/or inducing flowers Et...

An increase in starch content of cells in the abscission zone of the cotton explant appeared correlated with an increase in number of cells. A large increase in the number of cells in the abscission zone, concomitant with an increase in starch content, followed treatment with gibberellin as compared to auxin. In the final stages of abscission starch was hydrolyzed in the cells of the separation...

A ligand-receptor module comprised of the peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) and the receptor-like kinases HAESA (HAE) and HAESA-LIKE2 (HSL2) activates organ abscission in Arabidopsis flowers. Another set of receptor-like kinases, including EVERSHED (EVR), restricts the extent of cell separation in abscission zones by potentially altering HAE/HSL2 localization or activity. The ...