Peking University, Oct. 10，2011: The research paper named “CFL1, a WW Domain Protein, Regulates Cuticle Development by Modulating the Function of HDG1, a Class IV Homeodomain Transcription Factor, in Rice and Arabidopsis”, an academic result of PKU Prof. Gu Hongya’s research group, was published on The Plant Cell online on Sep. 27.

Terrestrial plants are believed to have evolved from aquatic ancestors and have evolved a heterogeneous lipophilic covering layer, the cuticle, which prevents excessive water loss from plants and protects them against various biotic and abiotic stresses. The cuticle also plays an important role in reflecting or dissipating detrimental radiation, resisting invasion by insects and pathogens and plant development.

The cuticle changes continuously during plant development to maintain its balance between rigidity and flexibility and it is a mixture of different molecules, which involve many enzymatic reactions and cellular transportation. Therefore, the synthesis and development of cuticle needs to be regulated meticulously.

Although more and more genes with roles in cuticle biosynthesis have been described in recent years, few genes that regulate cuticle development have been reported, and the regulatory mechanisms remain unclear.

Led by Prof. Gu Hongya at School of Life Sciences of Peking University, who is a member of State Key Laboratory of Protein and Plant Gene Research, a group of scholars have found a new gene which regulates the process and published their result on The Plant Cell.

They identified a rice (Oryza sativa) dominant curly leaf mutant, curly flag leaf1 (cfl1), cloned CFL1, which encodes a WW domain protein and found its homologous gene At CFL1 in Arabidopsis thaliana. Then they overexpressed both rice and Arabidopsis CFL1 in Arabidopsis thaliana; these transgenic plants showed severely impaired cuticle development, similar to that in cfl1 rice. Reduced expression of At CFL1 resulted in reinforcement of cuticle structure.

By cooperating with Prof. Lukas Schreiber from University Bonn in Germany, they found more than one components of cuticle changed in those transgenic plants. Further study suggested that rice and Arabidopsis CFL1 negatively regulate cuticle development by affecting the function of HDG1, a class IV homeodomain-leucine zipper transcription factor, which regulates two cuticle development-associated genes, BDG and FDH.

Presently, most researches about cuticle development are focusing on the synthesis and transportation of its components, but few are working on the regulation of gene expression. By the research, Prof. Gu Hongya with her group has not only found a new pathway to regulate the cuticle development, but also provided another way of thinking in the study of its regulation of gene expression.

Written by: Xu Xinyi
Edited by: Cao Yixing
Source: PKU News (Chinese)