Systemic induction of the biosynthesis of terpenic compounds in Digitalis lanata.
A bacterial screening was carried out in the rhizosphere of two Digitalis species, D. thapsi and D. parviflora, both at the vegetative stage and at flowering. A total of 480 isolates were characterised at genus level, Bacillus being the dominant genera in all cases. Fifty percent of the Bacillus strains isolated from each species were analysed by PCR-RAPDs. At 85% similarity, 12 groups separated for D. thapsi and 18 for D. parviflora. One strain of each group was selected for biological assay on D. lanata, evaluating growth promotion and cardenolide content in leaves after inoculation performed in the root system. The plant parameters evaluated were leaf surface area, shoot and root dry weight and leaf number. Lanatoside C content was evaluated by HPLC. Only 17 strains caused significant increases in at least one of the parameters evaluated. The most striking result was that some strains promoted growth and increased cardenolide content at the same time. This effect was detected on leaves while inoculation was carried out on roots. Interestingly, these two parameters are not enhanced simultaneously under regular conditions in pot or in tissue cultures.
Gutierrez Mañero
Francisco Javier
FJ
Universidad San Pablo CEU, Facultad CC. Experimentales y de la Salud, PO Box 67, 28668 Boadilla del Monte Madrid, Spain. Igutma@ceu.es
Ramos
Beatriz
B
Lucas García
Jose Antonio
JA
Probanza
Agustín
A
Barrientos Casero
Maria Luisa
ML
D001407:Bacillus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004070:Digitalis / Q000378:metabolism* / Q000382:microbiology*; D010802:Phylogeny; D019105:Random Amplified Polymorphic DNA Technique; D013045:Species Specificity; D013729:Terpenes / Q000378:metabolism*
D004269:DNA, Bacterial; D013729:Terpenes