U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

The production and release of living root cap border cells is a function of root apical meristem type in dicotyledonous angiosperm plants

Author:
Hamamoto, L., Hawes, M.C., Rost, T.L.
Source:
Annals of botany 2006 v.97 no.5 pp. 917-923
ISSN:
0305-7364
Subject:
Vigna unguiculata, Helianthus annuus, developmental stages, Phaseolus vulgaris, Brassica napus, Pisum sativum, Solanum melongena, Capsicum annuum, Gossypium hirsutum, Daucus carota, Nicotiana tabacum, Sesbania exaltata, Arabidopsis thaliana, apical meristems, plant development, Glycine max, Cucumis sativus, Cucumis melo, root growth, ultrastructure, Solanum lycopersicum var. lycopersicum, Petunia hybrida, Citrullus lanatus, root cap, Luffa aegyptiaca
Abstract:
BACKGROUND AND AIMS: The root apical meristems (RAM) of flowering plant roots are organized into recognizable pattern types. At present, there are no known ecological or physiological benefits to having one RAM organization type over another. Although there are phylogenetic distribution patterns in plant groups, the possible evolutionary advantages of different RAM organization patterns are not understood. Root caps of many flowering plant roots are known to release living border cells into the rhizosphere, where the cells are believed to have the capacity to alter conditions in the soil and to interact with soil micro-organisms. Consequently, high rates of border cell production may have the potential to benefit plant growth and development greatly, and to provide a selective advantage in certain soil environments. This study reports the use of several approaches to elucidate the anatomical and developmental relationships between RAM organization and border cell production. METHODS: RAM types from many species were compared with numbers of border cells released in those species. In addition, other species were grown, fixed and sectioned to verify their organization type and capacity to produce border cells. Root tips were examined microscopically to characterize their pattern and some were stained to determine the viability of root cap cells. KEY RESULTS: The first report of a correlation between RAM organization type and the production and release of border cells is provided: species exhibiting open RAM organization produce significantly more border cells than species exhibiting closed apical organization. Roots with closed apical organization release peripheral root cap cells in sheets or large groups of dead cells, whereas root caps with open organization release individual living border cells. CONCLUSIONS: This study, the first to document a relationship between RAM organization, root cap behaviour and a possible ecological benefit to the plant, may yield a framework to examine the evolutionary causes for the diversification of RAM organization types across taxa.
Agid:
683038