Study of Adventitious Root Formation Through Lateral Root-Specific mRNA and Rooting-Associated Promoters in Pinus contorta

Abstract

Adventitious root formation, by auxin treatment, on 20-day-old hypocotyls of Pinus contorta has been extensively studied at our department in recent years (Grönroos et al., 1993; Grönroos et al., 1987). Those studies have shown that there are great morphological similarities between lateral root formation and auxin-induced adventitious root formation. We have isolated cDNA clones presumably involved in early processes of lateral root formation, and their significance for adventitious root formation are under investigation. By a wound and inoculation procedure with Agrobacterium rhizogenes on hypocotyl cuttings (see Grönroos et al. elsewhere in this book), we have been able to study different promoter-GUS constructs in developing transformed roots. The armed strain we use to induce root formation gives almost no alteration in root morphology compared to normal adventitious roots.