Structure and expression of a cDNA encoding zeaxanthin epoxidase, isolated from a wilt-related tomato (<i>Lycopersicon esculentum</i>Mill.) library

Abstract

Zeaxanthin epoxldase (ZE) catalyses two early steps in the abscisic acid (ABA) biosynthetic pathway. The sequence of a cDNA clone encoding ZE from Nicotiana plumbaginifolia was reported In 1996 and represented the first DNA sequence data on an ABA biosynthetic enzyme. The N. plumbaginifolia cDNA has been used to provide a heterologous probe to isolate a ZE cDNA from tomato (Lycopersicon esculentum Mill.). DNA and amino acid sequence differences are considered in relation to putative functional domans within the enzyme. The results of northern analysis in tomato are discussed in relation to the effects of water stress on ZE mRNA levels.