Apple Ripening-Related cDNA Clone pAP4 Confers Ethylene-Forming Ability in Transformed Saccharomyces cerevisiae

Abstract

galactose allowed these cells to convert ACC to ethylene. l h e transformed yeast converted 1-amino-2-ethylcyclopropane-1-carboxylate isomers to I-butene with the same lR,2S-stereoseledivity as achieved by the native ACC oxidase from apples. Both ascorbate and Fez+ ions stimulated the rate of the production of ethylene from ACC by the transformed yeast, whereas Cu2+ and Co2+ were strongly inhibitory; these are features of ACC oxidase. Northern analysis of the total RNA from nontransformed and transformed yeast showed that the ability to convert the ACC to ethylene was correlated with the synthesis and accumulation of a nove1 1.2-kb mRNA that hybridized to the cDNA clone pAP4. We conclude that the cDNA sequence of the clone pAP4 encodes ACC oxidase.Ethylene is significantly important in many stages of plant development and growth. It is becoming increasingly apparent that the biosynthesis of ethylene is developmentally regulated and temporally activated in response to numerous biotic and abiotic factors. An increase in the leve1 of synthesis of this simple olefin occurs during leaf and flower peta1 senescence and the ripening of climacteric fruits and, in many tissues, following periods of temperature, wounding, or anaerobic stress (Yang and Hoffman, 1984). Ethylene is synthesized from Met via the intermediates S-adenosyl-L-methionine and ACC, which is converted to ethylene by the terminal biosynthetic enzyme ACC oxidase (Adams and Yang, 1979; Yang and Hoffman, 1984).

Novel Broccoli 1-Aminocyclopropane-1-carboxylate Oxidase Gene (Bo-ACO3) Associated with the Late Stage of Postharvest Floret Senescence

“…Our results indicated that Bo-ACO3 was a functional gene and played a role in ethylene production of broccoli florets. Expression and regulation of Bo-ACO3 were quite different from those of ACO genes reported in other plants during development and senescence and in response to ethylene (8,9,14,(36)(37)(38)(39)(40)(41)(42)(43). Bo-ACO3 was detected only in the florets at a late stage of broccoli senescence (Figure 5A), whereas chlorophyll was lost from florets at an earlier senescence stage, particularly from the petal, and the color turned yellow at 3 DAH (Figure 5B).…”

1-Aminocyclopropane-1-carboxylic acid oxidase reaction mechanism and putative post-translational activities of the ACCO protein

“…The wild-type cDNA of apple ACCO ( Wilson et al . 1993 ) was cloned into the expression vector pET15b (Novagen Inc., Madison, WI, USA).…”

Molecular Cloning and Characterization of A Novel 1-Aminocyclopropane-1-carboxylate Oxidase Gene Involved in Ripening of Banana Fruits

“…Each 3 mL of host, untransformed and transformed yeast cells, were incubated with shaking at 30 °C until the A600 approximated 1.4. This culture was incubated with 30 mM sodium ascorbate, 0.1 mM FeSO4, and 1 mM ACC for 1 h with shaking at 240 rpm (48). The ethylene produced was assayed using a SHIMADZU Gas Chromatograph GC 14A.…”