Phytochrome Activities and Biological Activities of Genes for Phytochrome A of Horseradish in Horseradish Hairy Roots.

Abstract

Full-length cDNAs of ArPHYAs were fused with the 35S promoter of cauliflower mosaic virus (CaMV35SArPHYAs) and introduced into horseradish hairy roots. The phytochrome levels in hairy roots that had been transformed with CaMV35SArPHYAs were about 2-3 times higher than those in normal hairy roots. Though ArphyAs were photochemically active in horseradish hairy roots, the efficiency of ArphyAs on shoot formation was different among them. The efficiency of light-induced formation of adventitious shoots in horseradish hairy roots was greatest for ArphyA3 and smallest for ArphyA2. These results indicated that ArPHYAs isolated from horseradish encoded photochemically active phytochromes and that they were biologically active in horseradish.