The YORE‐YORE gene regulates multiple aspects of epidermal cell differentiation in Arabidopsis

Abstract

SummaryWe have identi®ed a new Arabidopsis mutant, yore-yore (yre), which has small trichomes and glossy stems. Adhesion between epidermal cells was observed in the organs of the yre shoot. The cloned YRE had high homology to plant genes involved in epicuticular wax synthesis, such as ECERIFERUM1 (CER1) and maize GLOSSY1. The phenotype of transgenic plants harboring double-stranded RNA interference (dsRNAi ) YRE was quite similar to that of the yre mutant. The amount of epicuticular wax extracted from leaves and stems of yre-1 was approximately one-sixth of that from the wild type. YRE promoter::GUS and in situ hybridization revealed that YRE was speci®cally expressed in cells of the L1 layer of the shoot apical meristem and young leaves, stems, siliques, and lateral root primordia. Strong expression was detected in developing trichomes. The trichome structure of cer1 was normal, whereas that of the yre cer1 double mutant was heavily deformed, indicating that epicuticular wax is required for normal growth of trichomes. Double mutants of yre and trichome-morphology mutants, glabra2 (gl2 ) and transparent testa glabra1 (ttg1), showed that the phenotype of the trichome structure was additive, suggesting that the wax-requiring pathway is distinct from the trichome development pathway controlled by GL2 and TTG1.

Analysis of TETRAKETIDE α-PYRONE REDUCTASE Function in Arabidopsis thaliana Reveals a Previously Unknown, but Conserved, Biochemical Pathway in Sporopollenin Monomer Biosynthesis

“…In agreement with this observation, bacteria transformed with a MS2 cDNA produce fatty alcohols from uncharacterized precursors (Doan et al, 2009). A loss-of-function mutation in the FACELESS POLLEN1/YORE-YORE/WAX2 gene that impacts exine structure and wax synthesis (Ariizumi et al, 2003;Chen et al, 2003;Kurata et al, 2003) was reported recently to be allelic to CER3, a gene previously described to fulfill an unknown function in wax synthesis (Rowland et al, 2007). DIHYDROFLA-VONOL 4-REDUCTASE-LIKE1 (DRL1), another gene required for pollen development and male fertility (Tang et al, 2009), shares sequence similarity with DIHYDROFLAVONOL REDUCTASE (DFR), a gene implicated in the biosynthesis of anthocyanins and proanthocyanidins (Shirley et al, 1992), but the DRL1 enzyme is also of unknown biochemical function.…”

Arabidopsis TRANSPARENT TESTA GLABRA2Is Directly Regulated by R2R3 MYB Transcription Factors and Is Involved in Regulation ofGLABRA2Transcription in Epidermal Differentiation

“…Scanning electron microscopy samples were prepared and observed as described previously (Kurata et al, 2003).…”

A Novel Fatty Acyl-CoA Synthetase Is Required for Pollen Development and Sporopollenin Biosynthesis inArabidopsis

“…DEX1 is a novel protein of unknown function thought to be localized to the plasmalemma. Other genes associated with exine production and male fertility include YORE-YORE/WAX2/FACELESSPOL-LEN1, encoding an enzyme apparently involved in wax biosynthesis (Ariizumi et al, 2003;Chen et al, 2003;Kurata et al, 2003) and the rice (Oryza sativa) Wax-deficient anther1 gene, a homolog of the Arabidopsis ECERIFERUM1 gene that encodes a putative membrane protein apparently required for very-longchain fatty acid metabolism (Jung et al, 2006).…”