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

• Processo: 15/50019-5
• Modalidade de apoio: Auxílio à Pesquisa - Publicações científicas - Artigo
• Data de Início da vigência: 01 de abril de 2015
• Data de Término da vigência: 30 de setembro de 2015
• Área do conhecimento: Ciências Biológicas - Botânica - Fisiologia Vegetal
• Pesquisador responsável: Gilberto Barbante Kerbauy
• Beneficiário: Gilberto Barbante Kerbauy
• Instituição Sede: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brasil
• Assunto(s): Crescimento vegetal Plantas cultivadas Orquídea Catasetum fimbriatum Etilenos Publicações de divulgação científica Artigo científico
• Palavra(s)-Chave do Pesquisador: Catasetum Fimbriatum | Development Plasticity | Epiphytic Orchid | Ethylene | Velamen

Resumo

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)