title: Effect of clinorotation on in vitro cultured explants of Mentha piperita L.
abstract: An in vitro culture system was used to study the influence of gravity on axillary shoot formation and adventitious root regeneration in Mentha piperita L. The direction of the gravity vector was altered by displacing stem node explants in different orientations. Also, microgravity conditions were simulated by rotating the explants on a horizontal clinostat so that the main axis of nodes was either parallel (Cpa) or perpendicular to the clinostat axis (Ccp and Ccf, centripetally and centrifugally oriented, respectively). Mint nodes were cultured on solidified Linsmaier and Skoog's medium [Physiol. Plant. 18 (1965) 100] adding a filter-sterilized aqueous solution of 2 mg/l benzyladenine (BA) in half of the cultures. The proliferation of axillary shoots as well as adventitious root formation were not affected by altering upright explant orientation. On the contrary clinorotation was able to modify plantlet development. In absence of BA, leaf width was hindered by Cpa treatment and penultimate internode length was enhanced by Ccp. Furthermore, a negative effect of Cpa treatment was observed in root length parameter, while Ccp increased the root number both in absence and in presence of BA. An effect strictly connected to clinorotation in presence of BA was the occurrence of hyperhydricity. Moreover, explants under clinorotation treatments switched their gravitropic response modifying shoot curvature.
authors.affiliation: Dipartimento di Biologia delle Piante Agrarie, Universita di Pisa, Pisa, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Paolicchi
authors.forename: Anna
authors.initials: A
authors.lastname: Mensuali-Sodi
authors.forename: Franco
authors.initials: F
authors.lastname: Tognoni
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001593:Benzyl Compounds; D046508:Culture Techniques; D006112:Gravitation; D018522:Gravitropism / Q000502:physiology*; D007701:Kinetin; D027541:Mentha / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D010937:Plant Growth Regulators / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D011687:Purines; D012399:Rotation; D018474:Weightlessness Simulation
chemical_list: D001593:Benzyl Compounds; D010937:Plant Growth Regulators; D011687:Purines; D000225:Adenine; C480551:benzylaminopurine; D007701:Kinetin