Biotechnology for flower development and pigment production in tagetes erecta

Marigold (Tagetes erecta) is an asteraceous plant of industrial and medicinal importance. This plant is native to Mexico, where it is used in traditional medicine and for ornamental purposes. Marigold contains bioactive compounds that exhibit nemati-cidal, fungicidal and insecticidal activity. The flowers are utilized as a source of pigments for food coloring in industry, mainly of poultry skin and eggs. Lutein is the main pigment in marigold flowers. It is synthesized through the isoprenoid pathway and can be potentially modified to produce new high-value-added carotenoids or increase pigment production. In this study we report the isolation and analysis of genes related to flower development and pigment production. The genes were isolated from a flower cDNA library using heterologous probes, cloned into pBluescript SK and characterized by DNA sequence analysis. The inserts size ranged from 1200 to 1900 bp and the predicted amino acid exhibited a high homology with reported sequences. Northern blot analysis at different stages of flower development showed differential expression during plant growth, including flower development. In order to overexpress these gene sequences in marigold, we developed a protocol for plant regeneration and transformation in marigold. The possibility for molecular manipulation and its application for plant improvement were studied.