Changes in peroxidase activity, and level of phenolic compounds during light-induced plantlet regeneration from Eucalyptus camaldulensis Dehn. nodes in vitro

摘要

Node cultures of Eucalyptus camaldulensis Dehn inPetri dishes in vitro under darkness in the presence of anauxin developed meristematic agglomerates (4 to 6 diameter),i.e. dense shoot clusters in which outgrowth of numerous successive buds islimited. Similar cultures under a 16 photoperiod produced smallgreen plantlets with reduced leaves often presenting white hypertrophiedlenticels and very short roots crowning the stem bases. The use of half-litreglass vials under light allowed direct development of well-developed rootedplantlets, either in the presence of the same auxin or in the presence of acytokinin. Light favoured an increase in phenolic compounds and a reversevariation of peroxidase activity during the culture cycles. These aspects arediscussed in terms of a possible regulation of the endogenous auxin levelthrough a light control of peroxidase activity and the level of phenoliccompounds.