Abscission is a highly regulated and coordinated developmental process in plants. It is important to understand the processes leading up to the event, in order to better control abscission in crop plants. This has the potential to reduce yield losses in the field and increase the ornamental value of flowers and potted plants. A reliable method of abscission induction in poinsettia (Euphorbia pu...

Abscission is a cell separation process by which plants can shed organs such as fruits, leaves, or flowers. The process takes place in specific locations termed abscission zones. In fruit crops like citrus, fruit abscission represents a high percentage of annual yield losses. Thus, understanding the molecular regulation of abscission is of capital relevance to control production. To identify ge...

Three types of whole plant experiments are presented to substantiate the concept that an important function of ethylene in abscission is to reduce the transport of auxin from the leaf to the abscission zone. (a) The inhibitory effect of ethylene on auxin transport, like ethylene-stimulated abscission, persists only as long as the gas is continuously present. Cotton (Gossypium hirsutum L. cv. St...

Mammalian cytokinetic abscission is mediated by the ESCRT membrane fission machinery. While much has been clarified on the topology and kinetics of abscission through high-resolution microscopy, key questions regarding the mechanism of abscission remain open. Here we apply cryogenic soft-X-ray tomography to elucidate new ultrastructural details in the intercellular membrane bridge connecting ce...

Suimnwijitiry. The potential role of indoleactic acid (IAA)-oxidase as an in vivo abscission regullating system in the cotton (Gossvpiutiii hirsttuni L.) cotyledonary explant was investigated. Phenols (utsutally monophenols), which are cofactors of cotton IAA-oxidase in vitro, accelerated abscission. Phenols (tustually orthodihydroxyphenols), which inhibit cotton IAA-oxidase in vitro, inhibited...

Cellulase activity was measured in soybean (Glycine max) leaf abscission zones, flower abscission zones, pod abscission zones, apical buds, and adventitious rooting hypocotyls. Immunoprecipitation data showed that a cellulase immunologically similar to the bean abscission cellulase (isoelectric point 9.5) is present in soybean leaf, flower, and pod abscission zones, but is not present in soybea...

In plants, abscission removes senescent, injured, infected, or dispensable organs. Induced by auxin depletion and an ethylene burst, abscission requires pronounced changes in gene expression, including genes for cell separation enzymes and regulators of signal transduction and transcription. However, the understanding of the molecular basis of this regulation remains incomplete. To examine gene...

The 'NoCut', or Aurora B abscission checkpoint can be activated if DNA is retained in the cleavage furrow after completion of anaphase. Checkpoint failure leads to incomplete abscission and a binucleate outcome. These phenotypes are also observed after loss of PKCɛ in transformed cell models. Here we show that PKCɛ directly modulates the Aurora B-dependent abscission checkpoint by phosphorylati...

Sphingolipids, found in membranes of eukaryotic cells, have been demonstrated to carry out functions in various processes in plant cells. However, the roles of these lipids in fruit abscission remain to be determined in plants. Biochemical and fluorescence microscopy imaging approach has been adopted to investigate the accumulation and distribution of sphingolipids during mature-fruit abscissio...

The calcium content and distribution across the abscission zones of (2-chloroethyl) phosphonic acid-treated bean (Phaseolus vulgaris L. var. Contender) leaves were lower and not uniformly distributed as compared to the control. Calcium chloride-treated bean leaves had a higher calcium content, with more calcium localized in the potential abscission layer. Ethephon treatment promoted abscission ...