Towards map-based cloning of two genes involved in iron acquisition and metabolism in tomato

Iron is an important micronutrient element of plants. For mobilization and uptake of iron from soil, plants use different active mechanisms. In the la st two decades, many researches have focused on the physiological and bioch emical basis of iron uptake and metabolism in plants. Little is known about genes involved in the uptake process from soil and their regulation in viv o. To study molecular biology of iron uptake and metabolism in strategy I p lants, the mutants chloronerva (chln) and T3238fer (fer) described in tomat o (Lycopersicon esculentum Mill.) are very informative mutants. The fer gen e is epstatic over the chin gene in double mutants and controls the whole p rocess of iron deficiency response reaction in strategy I plants while the chin gene is responsible for synthesis of the non-protein amino acid, nicot ianamine, which is a key substance in iron metabolism of all higher plants. We try to isolate the both genes by map-based cloning approach. In this pa per we describe our strategy and an actual state of progress for the isolat ion of the fer and chin genes in tomato. The isolation of the two genes wou ld represent an important first step for understanding the molecular mechan isms controlling strategy I. iron-uptake responses.