To identify novel genes engaged in plant epidermal development, we characterized the phenotypic variability of rosette leaf epidermis of 310 sequenced Arabidopsis thaliana accessions, focusing on trichome shape and distribution, compositional characteristics of the trichome cell wall, and histologically detectable metal ion distribution. Some of these traits correlated with cLimate parameters of our accession's locations of origin, suggesting environmental selection. A novel metal deposition pattern in stomatal guard cells was observed in some accessions. Subsequent GWAS analysis identified 1546 loci with protein sequence-altering SNPs associated with one or more traits, including 5 genes with previously reported relevant mutant phenotypes and 80 additional genes with known or predicted roles in relevant developmental and cellular processes. Some candidates, including GFS9/TT9, exhibited environmentally correlated allele distribution. Several large gene famiLies, namely DUF674, DUF784, DUF1262, DUF1985, DUF3741, cytochrome P450, receptor-Like kinases, Cys/His-rich C1 domain proteins and formins were overrepresented among the candidates for various traits, suggesting epidermal development-related functions. A possible participation of formins in guard cell metal deposition was supported by observations in available loss of function mutants. Screening of candidate gene lists against the STRING interactome database uncovered several predominantly nuclear protein interaction networks with possible novel roles in epidermal development.

• Klíčová slova
• Arabidopsis thaliana, BioClim, GWAS, guard cell, metal accumulation, phenotypic variability, trichome,
• MeSH
• Arabidopsis * genetika   růst a vývoj   metabolismus   MeSH
• celogenomová asociační studie * MeSH
• epidermis rostlin * genetika   metabolismus   růst a vývoj   MeSH
• fenotyp MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• kovy metabolismus   MeSH
• listy rostlin genetika   metabolismus   růst a vývoj   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• rostlinné geny MeSH
• trichomy * genetika   metabolismus   růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kovy MeSH
• proteiny huseníčku MeSH

Arabidopsis (Arabidopsis thaliana) root hairs develop as long tubular extensions from the rootward pole of trichoblasts and exert polarized tip growth. The establishment and maintenance of root hair polarity is a complex process involving the local apical production of reactive oxygen species generated by A. thaliana nicotinamide adenine dinucleotide phosphate (NADPH) oxidase respiratory burst oxidase homolog protein C/ROOT HAIR-DEFECTIVE 2 (AtRBOHC/RHD2). Loss-of-function root hair defective 2 (rhd2) mutants have short root hairs that are unable to elongate by tip growth, and this phenotype is fully complemented by GREEN FLUORESCENT PROTEIN (GFP)-RHD2 expressed under the RHD2 promoter. However, the spatiotemporal mechanism of AtRBOHC/RHD2 subcellular redistribution and delivery to the plasma membrane (PM) during root hair initiation and tip growth are still unclear. Here, we used advanced microscopy for detailed qualitative and quantitative analysis of vesicular compartments containing GFP-RHD2 and characterization of their movements in developing bulges and growing root hairs. These compartments, identified by an independent molecular marker mCherry-VTI12 as the trans-Golgi network (TGN), deliver GFP-RHD2 to the apical PM domain, the extent of which corresponds with the stage of root hair formation. Movements of TGN/early endosomes, but not late endosomes, were affected in the bulging domains of the rhd2-1 mutant. Finally, we revealed that structural sterols might be involved in the accumulation, docking, and incorporation of TGN compartments containing GFP-RHD2 to the apical PM of root hairs. These results help in clarifying the mechanism of polarized AtRBOHC/RHD2 targeting, maintenance, and recycling at the apical PM domain, coordinated with different developmental stages of root hair initiation and growth.

• MeSH
• Arabidopsis genetika   růst a vývoj   MeSH
• buněčná membrána genetika   metabolismus   MeSH
• genetická variace MeSH
• genotyp MeSH
• kořeny rostlin genetika   růst a vývoj   MeSH
• mutace MeSH
• organogeneze rostlin genetika   MeSH
• regulace genové exprese u rostlin MeSH
• rostlinné geny MeSH
• trichomy genetika   růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH