The response of Spartium junceum roots to slope: anchorage and gene factors.
OBJECTIVE
Plant anchorage is governed by complex, finely regulated mechanisms that occur at a morphological, architectural and anatomical level. Spanish broom (Spartium junceum) is a woody plant frequently found on slopes--a condition that affects plant anchorage. This plant grows throughout the Mediterranean area where it plays an important role in preventing landslides. Spanish broom seedlings respond promptly to slope by altering stem and root morphology. The aim of this study was to investigate the mechanisms whereby the root system of Spanish broom seedlings adapts to ensure anchorage to the ground.


METHODS
Seedlings were grown in tilted and untilted pots under controlled conditions. The root apparatus was removed at different times of growth and subjected to morphological, biomechanical and molecular analyses.


RESULTS
In slope-grown seedlings, changes in root system morphology, pulling strength and chemical lignin content, all features related to plant anchorage in the soil, were related to seedling age. cDNA-AFLP analysis revealed changes in the expression of several genes in root systems of slope-grown plants. BLAST analysis showed that some differentially expressed genes are homologues of genes induced by environmental stresses in other plant species, and/or are involved in the production of strengthening materials.


CONCLUSIONS
Plants use various mechanisms/strategies to respond to slope depending on their developmental stage.
Scippa
Gabriella Stefania
GS
Dipartimento di Scienze e Tecnologie per l'Ambiente ed il Territorio, Università degli Studi del Molise, Via Mazzini 8, 86170 Isernia, Italy. scippa@unimol.it
Di Michele
Michela
M
Di Iorio
Antonino
A
Costa
Antonello
A
Lasserre
Bruno
B
Chiatante
Donato
D
D018076:DNA, Complementary; D018744:DNA, Plant; D020869:Gene Expression Profiling; D005843:Geography; D008031:Lignin / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development*; D018520:Plant Shoots / Q000033:anatomy & histology; D012150:Polymorphism, Restriction Fragment Length; D036226:Seedlings / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development*; D017422:Sequence Analysis, DNA; D031302:Spartium / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development*
D018076:DNA, Complementary; D018744:DNA, Plant; D008031:Lignin