Expression of genes for alcohol dehydrogenase and pyruvate decarboxylase in petals of cut carnation flowers in response to hypoxia and anoxia

Abstract

Two full‐length cDNAs encoding alcohol dehydrogenase (ADH, EC 1.1.1.1) and pyruvate decarboxylase (PDC, EC 4.1.1.1), named Dcadh1 and Dcpdc1, respectively, were cloned from the petals of cut carnation flowers exposed to hypoxia (1.5% O2). Dcadh1 and Dcpdc1 transcripts were accumulated in large amounts in the petals of carnation flowers 2 and 3 h after the exposure of the flowers to hypoxia and anoxia, respectively. The accumulation of the transcripts was accompanied by subsequent increases in the ADH and PDC activities in the petals. The rapid and massive induction of Dcadh1 and Dcpdc1 expression and their enzymatic activities make these genes useful molecular markers for the early events of hypoxic adaptation in cut carnation flowers. The long‐term objective of this research is to induce a hypoxia‐like response in cut carnation flowers maintained under normoxic conditions in order to extend their vase life. Cut carnation flowers represent a good model system to study the molecular triggering of the hypoxic response.