TTL3 in Lateral Root Growth and Development in Arabidopsis

Novel regulatory elements taking part in lateral root development were searched in the forward screening of Arabidopsis gene-trap lines. We have identified TTL3 gene (Tetratricopeptide-repeat Thioredoxin-Like 3, AT2G42580) encoding protein, containing thioredoxin-like domain and three tandem tetratricopeptide domains. Root system image analyses revealed that ttl3 knock out produces shorter lateral roots comparing to WT plants. Root bending assay suggests that ttl3 mutation delays the lateral root primordia development, while the number of initiation evens was not affected. Translation fusions pTTL3::TTL3-GFP confirm the TTL3 expression patterns to the lateral root tip and with 35S::TTL3-mCherry allowed for the identification of cellular distribution of this cytoplasmic protein. Our data indicate that TTL3 protein is interacting with microtubules and is most likely interconnected with vesicle transport in Arabidopsis cells. Further analysis of interacting partners of TTL3 is in progress.