Transcriptional and functional classification of the GOLVEN/ROOT GROWTH FACTOR/CLE-like signaling peptides reveals their role in lateral root and hair formation.
The GOLVEN (GLV)/ROOT GROWTH FACTORS/CLE-Like small signaling peptide family is encoded by 11 genes in Arabidopsis (Arabidopsis thaliana). Some of them have already been shown to control root meristem maintenance, auxin fluxes, and gravitropic responses. As a basis for the detailed analysis of their function, we determined the expression domains for each of the 11 GLV genes with promoter-reporter lines. Although they are collectively active in all examined plant parts, GLV genes have highly specific transcription patterns, generally restricted to very few cells or cell types in the root and shoot and in vegetative and reproductive tissues. GLV functions were further investigated with the comparative analysis of root phenotypes induced by gain- and loss-of-function mutants or in treatments with GLV-derived synthetic peptides. We identified functional classes that relate to the gene expression domains in the primary root and suggest that different GLV signals trigger distinct downstream pathways. Interestingly, GLV genes transcribed at the early stages of lateral root development strongly inhibited root branching when overexpressed. Furthermore, transcription patterns together with mutant phenotypes pointed to the involvement of GLV4 and GLV8 in root hair formation. Overall, our data suggest that nine GLV genes form three subgroups according to their expression and function within the root and offer a comprehensive framework to study the role of the GLV signaling peptides in plant development.
Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium.
Ana
A
Fernandez
Andrzej
A
Drozdzecki
Kurt
K
Hoogewijs
Anh
A
Nguyen
Tom
T
Beeckman
Annemieke
A
Madder
Pierre
P
Hilson
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013997:Time Factors
D029681:Arabidopsis Proteins; D020033:Protein Isoforms; D049452:Green Fluorescent Proteins