Data/hora: 03/06/2024 08:08:16

Provedor de dados: | Revista Brasileira de Fisiologia Vegetal
País: | Brazil
Título: | Dry matter partitioning differences between shoots and roots in two contrasting genotypes of orchids and their relationship with endogenous levels of auxins, cytokinins and abscisic acid
Autores: | PERES,LÁZARO E. P.; MAJEROWICZ,NIDIA; KERBAUY,GILBERTO B.
Data: | 2001-01-01
Ano: | 2001
Palavras-chave: | Epiphytes; Development; In vitro culture; Orchids; Plant hormones.
Resumo: | Epiphytic orchids have been considered an interesting model for plant development and may have unusual features related to the hormonal control of shoot and root growth. In the present experiment we have studied two genotypes of Catasetum fimbriatum Lindl. (Orchidaceae) with an inverse pattern of shoot and root dry matter accumulation. Whereas the CFC1 genotype directs 60% of dry matter towards the shoot system, this same amount is directed towards the root system in the CFC4 genotype. Differences in the endogenous content of cytokinins, IAA and ABA, as well as differences in IAA conjugation and oxidation in shoots and roots were observed in the two genotypes. These differences were correlated with their dry matter partitioning patterns. Thus, the genotype that directed 60% of dry matter towards the root system showed a 20-fold higher auxin accumulation in those organs, while the one that accumulated 60% of dry matter in the shoots showed a 10-fold higher cytokinin accumulation in this plant part. Based on the well established information about auxin and cytokinin biosynthesis, conjugation, oxidation, transport, and effect on organ growth, we have presented an integrative working hypothesis to interpret the data obtained in this study. This working hypothesis may also account for the understanding of the complex relationships involving the hormonal control of the relative growth of shoots and roots in other plant models.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000200007
Editor: | Sociedade Brasileira de Fisiologia Vegetal
Relação: | 10.1590/S0103-31312001000200007
Formato: | text/html
Fonte: | Revista Brasileira de Fisiologia Vegetal  v.13 n.2 2001
Fonte: | info:eu-repo/semantics/openAccess