What’s new in Plant-Soil-Microbe Interactions
GRR VASI
Végétal - Agronomie - Sols - Innovation
Do you know …
…that resurrection plants of southern Africa are highly tolerant
to dehydration? They can survive severe water loss in a very dry environment!
Responsables scientifiques :
Pr A. Driouich
Glyco-MEV, EA 4358
Université de Rouen
76821 Mont-Saint-Aignan cedex
[email protected]
Dr K. Laval
Directeur de la recherche
ESITPA
3, rue du Tronquet
76134 Mont-Saint-Aignan cedex
[email protected]
A variety of Southern African resurrection plants were surveyed using high-throughput cell
wall profiling tools. Species evaluated were the dicotyledons, Myrothamnus flabellifolia and
Craterostigma plantagineum; the monocotyledons, Xerophyta viscosa, Xerophyta schlecterii,
Xerophyta humilis and the resurrection grass Eragrostis nindensis, as well as a pteridophyte,
the resurrection fern, Mohria caffrorum. Comparisons were made between hydrated and
desiccated leaf and frond material, with respect to cell wall composition and polymer
abundance, using monosaccharide composition analysis, FT-IR spectroscopy and
comprehensive microarray polymer profiling in combination with multivariate data analysis.
The data obtained suggest that three main functional strategies appear to have evolved to prepare plant cell walls for desiccation.
Arabinan-rich pectin and arabinogalactan proteins are found in the resurrection fern M. Caffrorum and the basal angiosperm M.
flabellifolia where they appear to act as ‘pectic plasticizers’. Dicotyledons with pectin-rich walls, such as C. plantagineum, seem to
use inducible mechanisms which consist of up-regulating wall proteins and osmoprotectants. The hemicellulose-rich walls of the
grass-like Xerophyta spp. and the resurrection grass E. nindensis were found to contain highly arabinosylated xylans and
arabinogalactan proteins. These data support a general mechanism of ‘plasticising’ the cell walls of resurrection
plants to
desiccation and implicate arabinose-rich polymers (pectin-arabinans, arabinogalactan proteins and arabinoxylans) as the
major contributors in ensuring flexibility is maintained and rehydration is facilitated in these plants.
See the paper by J.P. Moore et al, 2013 http://www.ncbi.nlm.nih.gov/pubmed/23117392
mars 2014