Can Changes in Starch Content and Peroxidase Activity Be Used as Rooting Phase Markers for Rhododendron Leaf Bud Cuttings?

Abstract

We examined whether peroxidase activity in cutting bases and leaves and starch content in cutting bases can be used as rooting phase markers in the elepidote rhododendron cv. 'Babites Baltais' (Rhododendron L.). Changes in peroxidase activity in cutting leaves and bases, as well as starch content in cutting bases, were determined in relation to anatomical stages of rhizogenesis in leaf bud cuttings treated with 1% indole-3-butyric acid (IBA+) or without IBA (IBA-). The pattern of change of peroxidase activity was similar in cutting bases and leaves of IBAleaf bud cuttings. Three phases of adventitious root formation were identified: induction, initiation and expression. During the induction phase peroxidase activity decreased, but no anatomical changes were observed in the cuttings. Peroxidase activity increased in the initiation phase when adventitious root initials were formed. Peroxidase activity decreased during the expression phase when adventitious root primordia developed. The starch content of IBA-leaf bud cuttings decreased during the first few days and then gradually rose to maximum, followed by a sharp reduction and another increase at the end of the experiment. The changes of starch content did not coincide with rooting phases as peroxidase activity did, and cannot be used as a rooting phase marker in rhododendrons. Adventitious root formation did not occur in IBA+ leaf bud cuttings, so distinct rooting phases could not be observed. There was a significant correlation between peroxidase activity in cutting bases and leaves of IBA-leaf bud cuttings. Peroxidase activity in leaves of rhododendron leaf bud cuttings are potentially useful as a marker for rooting phases, but that requires further anatomical and physiological study of rooting in leaf bud cuttings.K Ke ey y w wo or rd ds s: : Peroxidase, starch, adventitious root, leaf bud cuttings, rhododendron.

Effect of indole-3-butyric acid on root formation in Alnus glutinosa microcuttings

“…Different authors have observed variations in the starch content of cells during rhizogenesis (De Klerk et al 1999, Li and Leung 2000, Megre et al 2011. In alder, the starch content of the cells increased after the first 24 hours, and was most evident in the microcuttings treated with IBA.…”

Propagation in Vitro and Experimental Field Cultivation ex Situ of Pulsatilla Turczaninovii Kryl. et Serg. (Ranunculaceae)

“…The content of soluble sugars on the 2nd day of root induction phase was positively correlated with rooting e ciency, and on the 7th with all studied rooting characteristics. Involvement of carbohydrates, particularly soluble sugars, in adventitious rooting process is usually related to their role as a carbon and energy source (Megre et al 2011, Otiende et al 2017. In this respect TSS can be considered the most impactful biomarker in studied species, and factors stimulating TSS synthesis could potentially enhance its rooting ability.…”

Effect of Calcarisporium arbuscula on adventitious root development and peroxidase activity in two elepidote rhododendron cultivars

“…Thus, study of these phases allows understanding the role of different rooting promoting treatments on biochemical course of the adventitious root formation. Previously we showed a correlation between peroxidase activity in leaves and bases of rhododendron leaf-bud cuttings, which allows to perform simultaneous anatomical study and peroxidase activity assay on the same plant material (Megre et al 2011). Thus, in current study rhododendron leaves were used for peroxidase activity assay.…”

“…Many studies have been performed to understand anatomical, physiological and biochemical processes during adventitious root formation and it is considered that adventitious rooting anatomically and biochemically consists of three subsequent phases: induction, initiation and expression (Gaspar et al 1994;Husen 2008;Naija et al 2008). In several plant species, including rhododendrons, changes in peroxidase activity have been suggested as a biochemical marker for these phases (Metaxas et al 2004;Syros et al 2004, Naija et al 2008Megre et al 2011). Thus, study of these phases allows understanding the role of different rooting promoting treatments on biochemical course of the adventitious root formation.…”