Genes with known preferential expression in epidermis or in vascular tissues were correctly identified by the microarray experiments using epidermal peels from stems
List of genes whose preferential or specific site of expression is epidermis (top of the list) or vascular tissues (bottom) as shown by techniques other than microarrays. The organ investigated and the reference is given. For known housekeeping genes (middle), only a few randomly selected examples are given. Molecular function of the proteins encoded by the genes: ACR4, putative receptor kinase; ATML1 and PDF2, homeodomain protein; AtPIN1, putative auxin efflux carrier protein; AtPPT1 (=cue1), phosphoenolpyruvate/phosphate translocator; CER2, unknown protein; CER5, ABC transporter; CBP20 and CBP80, nuclear cap binding protein; CER6 (=CUT1) and FDH (FIDDLEHEAD), β-ketoacyl-CoA synthase; LACERATA, fatty acid ω-hydroxylase; LACS2, long-chain acyl-CoA synthetase; L23a, 60S ribosomal protein; PPX1 and PPX2, protein phosphatase; UBQ1, ubiquitin extension protein; XCP1 and XCP2, cysteine peptidase; WAX2 (=YORE-YORE), unknown.
| Gene Locus | Gene Name | Expression Ratioa | Preferential Expression | Reference | |
|---|---|---|---|---|---|
| Top | Base | ||||
| Epidermal | |||||
| At3g59420 | ACR4 | 24.8 | 19.1 | Epidermis (all organs) | Tanaka et al. (2002) |
| At4g21750 | ATML1 | 6.2 | 5.5 | L1 layer of shoot apex | Sessions et al. (1999) |
| At4g04890 | PDF2 | 6.0 | 5.9 | L1 layer of shoot apex | Abe et al. (2003) |
| At4g24510 | CER2 | 4.1 | 6.0 | Epidermis | Xia et al. (1997) |
| At2g26250 | FDH | 4.0 | 3.9 | Epidermis | Yephremov et al. (1999); Pruitt et al. (2000) |
| At1g51500 | CER5 | 3.5 | 3.1 | Epidermis (stem) | Pighin et al. (2004) |
| At1g68530 | CER6 | 3.1 | 3.1 | Shoot epidermis | Millar et al. (1999) |
| At2g45970 | LACERATA | 3.1 | 2.2 | Epidermis-specific | Wellesen et al. (2001) |
| At5g57800 | WAX2 | 2.6 | 2.2 | L1 layer of shoot apex | Chen et al. (2003); Kurata et al. (2003) |
| At1g49430 | LACS2 | 2.5 | 1.2 | Epidermis (leaf) | Schnurr et al. (2004) |
| Ubiquitous | |||||
| At5g55260 | PPX2 | 1.6 | 1.6 | All tissues | Pujol et al. (2000) |
| At3g52590 | UBQ1 | 1.1 | 1.6 | Most tissues | Holtorf et al. (1995) |
| At4g26720 | PPX1 | 1.0 | 1.2 | All tissues | Pujol et al. (2000) |
| At3g18780 | Actin 2 | 0.9 | 0.7 | Vegetative tissues | An et al. (1996) |
| At2g13540 | CBP80 | 0.8 | 0.8 | Most tissues | Kmieciak et al. (2002) |
| At5g44200 | CBP20 | 0.7 | 1.0 | Most tissues | Kmieciak et al. (2002) |
| At1g49240 | Actin 8 | 0.6 | 0.7 | Vegetative tissues | An et al. (1996) |
| At3g55280 | L23a | 0.6 | 1.4 | Most tissues | Volkov et al. (2003) |
| Vascular | |||||
| At5g33320 | AtPPT1 | 0.4 | 1.0 | Stem vasculature | Knappe et al. (2003) |
| At1g73590 | AtPIN1 | 0.2 | 0.2 | Xylem and cambium | Gälweiler et al. (1998) |
| At4g35350 | XCP1 | 0.1 | 0.5 | Xylem | Funk et al. (2002) |
| At1g20850 | XCP2 | 0.1 | 0.3 | Xylem | Zhao et al. (2000) |
↵a Mean ratio calculated from four epidermis-to-stem gene expression ratios, i.e. ratio of transcripts in epidermis versus transcripts in stems, determined by microarray experiments (Affymetrix ATH1 GeneChip) using the epidermis of a stem section (top or base) and the whole-stem section (top or base) as a reference.