title: Transcription factors SOD7/NGAL2 and DPA4/NGAL3 act redundantly to regulate seed size by directly repressing KLU expression in Arabidopsis thaliana.
abstract: Although seed size is one of the most important agronomic traits in plants, the genetic and molecular mechanisms that set the final size of seeds are largely unknown. We previously identified the ubiquitin receptor DA1 as a negative regulator of seed size, and the Arabidopsis thaliana da1-1 mutant produces larger seeds than the wild type. Here, we describe a B3 domain transcriptional repressor NGATHA-like protein (NGAL2), encoded by the suppressor of da1-1 (SOD7), which acts maternally to regulate seed size by restricting cell proliferation in the integuments of ovules and developing seeds. Overexpression of SOD7 significantly decreases seed size of wild-type plants, while the simultaneous disruption of SOD7 and its closest homolog DEVELOPMENT-RELATED PcG TARGET IN THE APEX4 (DPA4/NGAL3) increases seed size. Genetic analyses indicate that SOD7 and DPA4 act in a common pathway with the seed size regulator KLU to regulate seed growth, but do so independently of DA1. Further results show that SOD7 directly binds to the promoter of KLUH (KLU) in vitro and in vivo and represses the expression of KLU. Therefore, our findings reveal the genetic and molecular mechanisms of SOD7, DPA4, and KLU in seed size regulation and suggest that they are promising targets for seed size improvement in crops.
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Yueying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Du
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Cui
authors.affiliation: College of Life and Health Sciences, Northeastern University, Shenyang 110004, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Hao
authors.affiliation: College of Life and Health Sciences, Northeastern University, Shenyang 110004, China.
authors.forename: Caixia
authors.initials: C
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China yhli@genetics.ac.cn.
authors.forename: Yunhai
authors.identifier: http://orcid.org/0000-0002-0025-4444
authors.initials: Y
authors.lastname: Li
mesh_terms: D017360:Arabidopsis / Q000033:anatomy & histology* / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D049109:Cell Proliferation; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D056625:Endosperm / Q000196:embryology / Q000235:genetics; D004843:Epistasis, Genetic; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D016153:Genes, Suppressor; D008969:Molecular Sequence Data; D009154:Mutation; D009929:Organ Size; D010641:Phenotype; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D021381:Protein Transport; D012097:Repressor Proteins / Q000378:metabolism*; D012639:Seeds / Q000033:anatomy & histology* / Q000166:cytology; D013347:Subcellular Fractions / Q000378:metabolism; D013489:Suppression, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D012097:Repressor Proteins; C000606163:SOD7 protein, Arabidopsis; D014157:Transcription Factors; D003577:Cytochrome P-450 Enzyme System; C546334:KLUH protein, Arabidopsis