1-Aminocyclopropane-1-carboxylic acid
1-Aminocyclopropane-1-carboxylic acid
1-Aminocyclopropane-1-carboxylic acid (ACC) is a small molecule that plays a crucial role in the biosynthesis of the plant hormone ethylene. It is an important intermediate in the ethylene biosynthesis pathway and is synthesized from the amino acid methionine.
Structure[edit]
1-Aminocyclopropane-1-carboxylic acid is a cyclopropane derivative, characterized by a three-membered ring structure. The molecule consists of an amino group (-NH_) and a carboxylic acid group (-COOH) attached to the cyclopropane ring. This unique structure contributes to its role in ethylene biosynthesis.
Biosynthesis[edit]
ACC is synthesized from S-adenosylmethionine (SAM) through the action of the enzyme ACC synthase. This reaction is a key regulatory step in the ethylene biosynthesis pathway. The conversion of SAM to ACC involves the removal of the methylthioadenosine group from SAM, resulting in the formation of ACC and 5'-methylthioadenosine.
Role in Ethylene Biosynthesis[edit]
Once synthesized, ACC is converted to ethylene by the enzyme ACC oxidase. This conversion requires oxygen and results in the production of ethylene, carbon dioxide, and hydrogen cyanide. Ethylene is a gaseous plant hormone that regulates various physiological processes, including fruit ripening, flowering, and leaf abscission.
Regulation[edit]
The production of ACC and its conversion to ethylene are tightly regulated processes in plants. Environmental factors such as light, temperature, and mechanical stress can influence the activity of ACC synthase and ACC oxidase, thereby affecting ethylene production. Additionally, plant hormones such as auxins and cytokinins can modulate ACC levels and ethylene biosynthesis.
Applications[edit]
Understanding the role of ACC in ethylene biosynthesis has practical applications in agriculture and horticulture. By manipulating ACC levels or the activity of ACC synthase and ACC oxidase, it is possible to control ethylene production and influence plant growth and development. This knowledge is used to enhance fruit ripening, delay senescence, and improve crop yield.
Related pages[edit]
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1-Aminocyclopropane-1-carboxylic acid
