Ethylene modulates the developmental plasticity and the growth balance between shoot and root systems in the vitro grown epiphytic orchid Catasetum fimbriatum

• Grant number: 15/50019-5
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: April 01, 2015
• End date: September 30, 2015
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Gilberto Barbante Kerbauy
• Grantee: Gilberto Barbante Kerbauy
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Ethylene is a well-known hormone involved in abiotic stresses in plant development. Several approaches conduced in this laboratory with the epiphytic orchid Catasetum fimbriatum have pointed out to a putative role of ethylene on both shoot and root growth regulation. In this study the effects of endogenous and exogenous ethylene coupled with an inhibiting-ethylene perception substance (MCP), as well as histological analysis were performed. Ethylene production enhanced to extend the plant developed, culminating with leaves shed. The early exposure to ethylene triggered root hair formation instead of velamen differentiation, decreasing both stem enlargement, cellular/organ elongation, and enhancing in leaf and root formation, bud initiation and cellular thickening, favoring biomass of allocation to roots. Convulsively, inhibition of ethylene perception over the plant growth phase resulted in an opposite morphogenetic response. The data indicate that periodic variations in ethylene concentration and/or sensitivity seem to modulate several developmental features in shoot and root systems of C. fimbriatum, which could have adaptive significance during the growing phase of this epiphytic orchid. (AU)