GENERATION OF TRANSFORMED ROOTS OF AGAVE SALMIANA Otto AND THEIR COLONIZATION BY GLOMUS INTRARADICES

Abstract

The present study is the first report on the induction of transformed roots in Agave salmiana Otto using Agrobacterium rhizogenes, as well as of the establishment of a micorrhizic fungus in the same roots. To achieve this, in vitro germinated plants were inoculated with several bacteria and acetosyringone concentrations, in several places (lea, stem and root). The time of cocultivation in darkness was of 6 d. Transformed roots were presented to the 25 d after inoculation. The higher transformation efficiency resulted from stem inoculation with 1x10⁹ bacteria mL^-1 and 200 µM acetosyringone, condition in which 63 % of transformed roots was obtained. The transgenic nature of the generated roots was verified by means of the GUS ssay and the transgenes were amplified through PCR in samples of root DNA. GUS activity was detected in 80 % of the proven roots, while rolB and nptII genes were amplified in 60 % of the DNA root samples analyzed by PCR. The ability of Glomus intraradices to colonize in vitro the transformed roots of A. salmiana was demonstrated with an efficiency of 70 %. The recovery of daughter spores was achieved with an average of 300 daughter spores per culture dish, after 6 months of inoculation.