The enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase promotes plant growth by sequestering and cleaving plant-produced ACC thereby lowering the level of ethylene in the plant. Decreased ethylene levels allow the plant to be more resistant to a wide variety of environmental stresses. Here the biochemical reaction mechanisms involved in ACC deaminase activity are critically reviewed.

A short post-harvest longevity remains a major limiting factor for many crops. Separation from plant leads quickly to ripening of fruits and senescence of flowers. In many species, ripening and senescence are ethyleneregulated. Thus, attempts have been made to retard the post-harvest processes by applying chemicals that inhibit ethylene synthesis. The long-term solution will probably be based o...

One of the central the mechanisms used by many soil bacteria to directly promote plant growth is the production of the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase. This enzyme facilitates plant growth as a consequence of the fact that it sequesters and cleaves plantproduced ACC (the immediate precursor of ethylene in plants), thereby lowering the level of ethylene in the plant. In ...

Ethylene is a gaseous plant hormone that most likely became a functional hormone during the evolution of charophyte green algae, prior to land colonization. From this ancient origin, ethylene evolved into an important growth regulator that is essential for myriad plant developmental processes. In vegetative growth, ethylene appears to have a dual role, stimulating and inhibiting growth, dependi...

Mitogen-activated protein kinases (MAPKs) are implicated in regulating plant growth, development, and response to the environment. However, the underlying mechanisms are unknown because of the lack of information about their substrates. Using a conditional gain-of-function transgenic system, we demonstrated that the activation of SIPK, a tobacco (Nicotiana tabacum) stress-responsive MAPK, induc...

The plant hormone ethylene regulates a wide range of developmental processes and the response of plants to stress and pathogens. Genetic studies in Arabidopsis led to a partial elucidation of the mechanisms of ethylene action. Ethylene signal transduction initiates with ethylene binding at a family of ethylene receptors and terminates in a transcription cascade involving the EIN3/EIL and ERF fa...

Ethylene inhibits cell division, DNA synthesis, and growth in the meristems of roots, shoots, and axillary buds, without influencing RNA synthesis. Apical dominance often is broken when ethylene is removed, apparently because the gas inhibits polar auxin transport irreversibly, thereby reducing the shoot's auxin content just as if the apex had been removed. A similar mechanism may underly ethyl...

Agrobacterium tumefaciens has a unique ability to transfer genes into plant genomes. This ability has been utilized for plant genetic engineering. However, the efficiency is not sufficient for all plant species. Several studies have shown that ethylene decreased the Agrobacterium-mediated transformation frequency. Thus, A. tumefaciens with an ability to suppress ethylene evolution would increas...

Despite its simple two-carbon structure, the olefin ethylene is a potent modulator of plant growth and development (Ecker, 1995). The plant hormone ethylene is involved in many aspects of the plant life cycle, including seed germination, root hair development, root nodulation, flower senescence, abscission, and fruit ripening (reviewed in Johnson and Ecker, 1998). The production of ethylene is ...

One of the earliest detectable events during plant-pathogen interaction is a rapid increase in ethylene biosynthesis. This gaseous plant stress hormone may be a signal for plants to activate defense mechanisms against invading pathogens such as bacteria, fungi, and viruses. The effect of ethylene on four plant genes involved in three separate plant defense response pathways was examined; these ...