title: Pleiotropic phenotypes of the sticky peel mutant provide new insight into the role of CUTIN DEFICIENT2 in epidermal cell function in tomato.
abstract: Plant epidermal cells have evolved specialist functions associated with adaptation to stress. These include the synthesis and deposition of specialized metabolites such as waxes and cutin together with flavonoids and anthocyanins, which have important roles in providing a barrier to water loss and protection against UV radiation, respectively. Characterization of the sticky peel (pe) mutant of tomato (Solanum lycopersicum) revealed several phenotypes indicative of a defect in epidermal cell function, including reduced anthocyanin accumulation, a lower density of glandular trichomes, and an associated reduction in trichome-derived terpenes. In addition, pe mutant fruit are glossy and peels have increased elasticity due to a severe reduction in cutin biosynthesis and altered wax deposition. Leaves of the pe mutant are also cutin deficient and the epicuticular waxes contain a lower proportion of long-chain alkanes. Direct measurements of transpiration, together with chlorophyll-leaching assays, indicate increased cuticular permeability of pe leaves. Genetic mapping revealed that the pe locus represents a new allele of CUTIN DEFICIENT2 (CD2), a member of the class IV homeodomain-leucine zipper gene family, previously only associated with cutin deficiency in tomato fruit. CD2 is preferentially expressed in epidermal cells of tomato stems and is a homolog of Arabidopsis (Arabidopsis thaliana) ANTHOCYANINLESS2 (ANL2). Analysis of cuticle composition in leaves of anl2 revealed that cutin accumulates to approximately 60% of the levels observed in wild-type Arabidopsis. Together, these data provide new insight into the role of CD2 and ANL2 in regulating diverse metabolic pathways and in particular, those associated with epidermal cells.
authors.affiliation: Department of Horticulture, Michigan State University, East Lansing, Michigan 48824, USA.
authors.forename: Satya Swathi
authors.initials: SS
authors.lastname: Nadakuduti
authors.forename: Mike
authors.initials: M
authors.lastname: Pollard
authors.forename: Dylan K
authors.initials: DK
authors.lastname: Kosma
authors.forename: Charles
authors.initials: C
authors.lastname: Allen
authors.forename: John B
authors.initials: JB
authors.lastname: Ohlrogge
authors.forename: Cornelius S
authors.initials: CS
authors.lastname: Barry
mesh_terms: D000483:Alleles; D000872:Anthocyanins / Q000378:metabolism; D017360:Arabidopsis / Q000378:metabolism; D002463:Cell Membrane Permeability; D002734:Chlorophyll / Q000378:metabolism; D002874:Chromosome Mapping; D005638:Fruit / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D056726:Genetic Association Studies; D056426:Genetic Loci / Q000235:genetics; D058685:Genetic Pleiotropy; D008031:Lignin / Q000378:metabolism; D018551:Solanum lycopersicum / Q000166:cytology / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D008563:Membrane Lipids / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D010802:Phylogeny; D019441:Plant Epidermis / Q000166:cytology* / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D018515:Plant Leaves / Q000033:anatomy & histology / Q000502:physiology / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D013499:Surface Properties; D014885:Waxes / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D008563:Membrane Lipids; D010940:Plant Proteins; D014885:Waxes; D002734:Chlorophyll; C000521:cutin; D008031:Lignin