Regulation of ethylene biosynthesis at the level of 1-aminocyclopropane-1-carboxylate oxidase (ACO) gene

Abstract

Ethylene, a gaseous plant hormone regulates essentially all physiological processes during the plant's life cycle. The practical implications of ethylene biosynthesis regulation for plant improvement have supported the continuous basic research on dissecting the structure of genes encoding ethylene biosynthetic enzymes, their differential expression patterns, and mechanisms underlying their transcriptional activity. ACC oxidase (ACO) is involved in the final step of ethylene production in plant tissues. In various plants several ACO isoforms have been isolated which are encoded by a multigenic family. There is a strong evidence that ACO gene expression is positively correlated to the ethylene production rates and its multiple isoforms are under development and environmental control. Thus, the regulation of ACO gene activity may act either as an additional or in several cases also as a main level for controlling ethylene biosynthesis in higher plants. This review summarizes in detail the knowledge about organization and gene structure, and transcriptional expression of ACO genes from different plant species. The perspectives of manipulating ACO gene as a method in biotechnological modification of ethylene synthesis are also discussed.

Producing the Ethylene Signal: Regulation and Diversification of Ethylene Biosynthetic Enzymes

“…3) and the innovation of posttranslational regulatory switches controlling ACS stability very early in flowering plant evolution. Conifers express ACO isoforms that group phylogenetically with the angiosperm ACOs known to synthesize ethylene as well as additional ACO-like isoforms, indicating that diversification of ACO isoforms occurred prior to the split of flowering plants and gymnosperms (Hudgins et al, 2006;Rudu s et al, 2013). The conservation of ACS and ACO isozymes in conifers suggests that the flowering plant ethylene biosynthesis pathway is conserved throughout seed plants, although the posttranslational regulation of specific isoforms likely differs between gymnosperms and angiosperms, because the gymnosperm ACS isoforms exhibit none of the known regulatory sequence motifs.…”

“…tomato ACO1-3 [Hamilton et al, 1991;Bidonde et al, 1998], MdACO1 from apple [Malus domestica; Dong et al, 1992], and Arabidopsis ACO4 [Gómez-Lim et al, 1993]) are known to exhibit ACC oxidase activity in vitro. Arabidopsis ACO2 and ACO3 and tomato ACO4 group with these active ACOs in phylogenetic analyses along with some conifer enzymes, whereas tomato ACO5 and Arabidopsis ACO1 and ACO5 cluster together in a sister clade that is separate from the group of enzymatically defined ACO isoforms (Hudgins et al, 2006;Rudu s et al, 2013). Furthermore, a set of Arabidopsis dioxygenase gene products with a more distant relationship to the known ACOs (Rudu s et al, 2013) have been designated as ACO6 to ACO13 on the basis of sequence similarity alone (Clouse and Carraro, 2014).…”

Cloning and expression of the 1-aminocyclopropane-1-carboxylic oxidase gene from Agrostis stolonifera

“…Located near the downstream part of the 5'-UTR, exon 1 has a varying length of ~100 bp, along with ~200 bp for exon 2, and ~300 bp for exon 3. Exon 4, consisting of ~300 bp, is adjacent to the 3'-UTR (Ruduś et al, 2013). A three-exon structure was also observed in A. thaliana AtACO1, Dianthus caryophyllus DcACO, and Z. mays AmACO35 (Ruduś et al, 2013).…”

“…By regulating ethylene biosynthesis in advanced plant species; the ACO gene may play an auxiliary or major role in this process. (Ruduś et al, 2013).…”

Unraveling the responses of mungbean (Vigna radiata) to mungbean yellow mosaic virus through 2D-protein expression

“…Aminocyclopropan -1-carboxylate oxidase (ACCO) (spot 3) is a cytosolic protein [5,43] involved in a two-step process of ethylene biosynthesis. ACCO acts as a precursor in the ethylene production; this determines the rate limiting factor in the pathway [41,43]. Apart from ethylene's involvement in defense signaling, it was also involved in increasing the damages caused during stress [22].…”