Growth and Vegetative Development
Shishkova, Svetlana , Moreno, Norma E. , Castillo-Díaz, Vicente , García-Mendoza, Edith , Arellano, Jesús , Dubrovsky, Joseph .
Regeneration of roots from callus reveals stability of the developmental program for determinate root growth in Sonoran Desert Cactaceae.
Determinate growth of the primary root in some Sonoran Desert Cactaceae involves meristem exhaustion and cell differentiation in the root tip. This mode of development is important for rapid lateral-root formation and a successful seedling establishment in a desert. The mechanisms involved in root meristem maintenance and determinate root growth in plants remain poorly understood. We have shown that roots regenerated from the callus of two Cactaceae species, Stenocereus gummosus and Ferocactus peninsulae, have a determinate growth pattern, similar to that of the primary root. Callus was induced from cotyledon and hypocotyl explants on media with high concentrations of 1-Naphthaleneacetic acid (NAA) and 6-Benzylaminopurine (BA); root regeneration was induced from callus on media with NAA only or with trace amount of BA. A plant genotype appeared to influence the efficiency of either callus formation or root regeneration from callus. In S. gummosus, root regeneration was efficient only in 12 h photoperiod and in F. peninsulae it was efficient both in the dark and photoperiod. This difference might be related to growth habit of these species: unlike F. peninsulae, S. gummosus forms many adventitious roots on stem branches. The determinate growth pattern of roots regenerated from callus suggests that the program of root development is very stable in these species. These findings together with our recent data on in vitro transformation permit quick analysis in the future of the role of certain Cactaceae genes in the determinate pattern of root growth via the regeneration of transgenic roots from transformed calli.
We thank S. Napsucialy-Mendivil for excellent technical help and DGAPA-PAPIIT, UNAM (project IN227206) for financial support.
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1 - Instituto de Biotecnología, Universidad Nacional Autónoma de México, Departamento de Biología Molecular de Plantas, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, CP 62210, México
2 - Instituto de Biotecnología, Universidad Nacional Autónoma de México, Departamento de Biología Molecular de Plantas
3 - Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México,, Programa de Genómica de Eucariotas
determinate root growth
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM