title: Shade avoidance 6 encodes an Arabidopsis flap endonuclease required for maintenance of genome integrity and development.
abstract: Flap endonuclease-1 (FEN1) belongs to the Rad2 family of structure-specific nucleases. It is required for several DNA metabolic pathways, including DNA replication and DNA damage repair. Here, we have identified a shade avoidance mutant, sav6, which reduces the mRNA splicing efficiency of SAV6. We have demonstrated that SAV6 is an FEN1 homologue that shows double-flap endonuclease and gap-dependent endonuclease activity, but lacks exonuclease activity. sav6 mutants are hypersensitive to DNA damage induced by ultraviolet (UV)-C radiation and reagents that induce double-stranded DNA breaks, but exhibit normal responses to chemicals that block DNA replication. Signalling components that respond to DNA damage are constitutively activated in sav6 mutants. These data indicate that SAV6 is required for DNA damage repair and the maintenance of genome integrity. Mutant sav6 plants also show reduced root apical meristem (RAM) size and defective quiescent centre (QC) development. The expression of SMR7, a cell cycle regulatory gene, and ERF115 and PSK5, regulators of QC division, is increased in sav6 mutants. Their constitutive induction is likely due to the elevated DNA damage responses in sav6 and may lead to defects in the development of the RAM and QC. Therefore, SAV6 assures proper root development through maintenance of genome integrity.
authors.affiliation: School of Life Sciences, Xiamen Plant Genetics Key Laboratory, Xiamen University, Xiamen 361102, China State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen 361102, China.
authors.forename: Yijuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Life Sciences, Xiamen Plant Genetics Key Laboratory, Xiamen University, Xiamen 361102, China.
authors.forename: Chunhong
authors.initials: C
authors.lastname: Wen
authors.affiliation: Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA College of Life Sciences, Zhejiang University, Hangzhou, China Suzhou Health College, Suzhou Key Laboratory of Biotechnology for Laboratory Medicine, Suzhou, 215009, Jiangsu Province, China.
authors.forename: Songbai
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA.
authors.forename: Binghui
authors.initials: B
authors.lastname: Shen
authors.affiliation: School of Life Sciences, Xiamen Plant Genetics Key Laboratory, Xiamen University, Xiamen 361102, China State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen 361102, China yitao@xmu.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Tao
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D045585:Flap Endonucleases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant / Q000235:genetics*; D006651:Histocytochemistry; D018546:Hypocotyl / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018519:Meristem / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D036361:Peptide Hormones / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C584817:ERF115 protein, Arabidopsis; C584818:PSK5 protein, Arabidopsis; D036361:Peptide Hormones; D014157:Transcription Factors; D045585:Flap Endonucleases