Class I TCP transcription factors regulate trichome branching and cuticle development in Arabidopsis

CAMOIRANO, ALEJANDRA; ARCE, AGUSTÍN L; ARIEL, FEDERICO D; ALEM, ANTONELA L; GONZALEZ, DANIEL H; VIOLA, IVANA L

JOURNAL OF EXPERIMENTAL BOTANY

OXFORD UNIV PRESS

Año: 2020

0022-0957

Trichomes and the cuticle are two specialized structures of the aerial epidermis important forplant organ development and interaction with the environment. In this study, we report thatplants affected in the function of the class I TEOSINTE BRANCHED 1, CYCLOIDEA, PCF(TCP) transcription factors TCP14 and TCP15 from Arabidopsis thaliana show overbranchedtrichomes in leaves and stems and increased cuticle permeability. We found that TCP15regulates the expression of MYB106, a MIXTA-like transcription factor involved inepidermal cell and cuticle development, and overexpression of MYB106 in a tcp14 tcp15mutant reduces trichome branch number. TCP14 and TCP15 are also required for theexpression of the cuticle biosynthesis genes CYP86A4, GPAT6 and CUS2, and of SHN1 andSHN2, two AP2/EREBP transcription factors required for cutin and wax biosynthesis. SHN1and CUS2 are also targets of TCP15, indicating that class I TCPs influence cuticle formationacting at different levels, through the regulation of MIXTA-like and SHN transcriptionfactors and of cuticle biosynthesis genes. Our study indicates that class I TCPs arecoordinators of the regulatory network involved in trichome and cuticle development.