Transcript profile changes associated with lateral root fasciation in temperature-sensitive mutants

ABSTRACT: Control of the dimensions of organ primordia is crucial for proper organogenesis in the development of multicellular organisms. Lateral root formation is a major type of plant organogenesis important for postembryonic development of the root system. Lateral root formation begins with a few rounds of asymmetric, anticlinal cell division (formative cell division) in the pericycle, which determines the basal dimensions of root primordia. Here we show, based on molecular genetic analysis of temperature-dependent fasciation (TDF) mutants of Arabidopsis thaliana, that mitochondria play an unexpected role in the restriction of formative cell division and thus in the control of the basal dimensions of lateral root primordia. Three TDF mutants, root redifferentiation defective 1 (rrd1), rrd2, and root initiation defective 4 (rid4), exhibit lateral root fasciation from excess formative cell division under high-temperature conditions. We identify RRD1 as encoding a poly(A)-specific ribonuclease (PARN)-like protein and RRD2 and RID4 as encoding pentatricopeptide repeat (PPR) proteins. Subcellular localization and predicted functions of these proteins implicate them in poly(A)-dependent RNA degradation in mitochondria. This characterization is supported by the finding that mitochondrial RNAs with poly(A) tails, most of which are mRNAs of respiratory chain components, accumulate at an unusually high level in these TDF mutants. Explants of three mutants (rrd1, rrd2, rid4) and wild type were cultured on B5 medium supplemented with 0.5 mg/L IBA for the induction of lateral root formation. After 12 hours of culture at 28C, explants were collected and used for microarray analysis. Analysis was performed in three biological replicates.

ORGANISM(S): Arabidopsis thaliana

SUBMITTER: Munetaka Sugiyama 

PROVIDER: E-GEOD-34595 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress