title: ROP3 GTPase contributes to polar auxin transport and auxin responses and is important for embryogenesis and seedling growth in Arabidopsis.
abstract: ROP GTPases are crucial for the establishment of cell polarity and for controlling responses to hormones and environmental signals in plants. In this work, we show that ROP3 plays important roles in embryo development and auxin-dependent plant growth. Loss-of-function and dominant-negative (DN) mutations in ROP3 induced a spectrum of similar defects starting with altered cell division patterning during early embryogenesis to postembryonic auxin-regulated growth and developmental responses. These resulted in distorted embryo development, defective organ formation, retarded root gravitropism, and reduced auxin-dependent hypocotyl elongation. Our results showed that the expression of AUXIN RESPONSE FACTOR5/MONOPTEROS and root master regulators PLETHORA1 (PLT1) and PLT2 was reduced in DN-rop3 mutant embryos, accounting for some of the observed patterning defects. ROP3 mutations also altered polar localization of auxin efflux proteins (PINs) at the plasma membrane (PM), thus disrupting auxin maxima in the root. Notably, ROP3 is induced by auxin and prominently detected in root stele cells, an expression pattern similar to those of several stele-enriched PINs. Our results demonstrate that ROP3 is important for maintaining the polarity of PIN proteins at the PM, which in turn ensures polar auxin transport and distribution, thereby controlling plant patterning and auxin-regulated responses.
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Jia-bao
authors.initials: JB
authors.lastname: Huang
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Huili
authors.initials: H
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Mingyan
authors.initials: M
authors.lastname: Wang
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Chunling
authors.initials: C
authors.lastname: Wang
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Jiaqing
authors.initials: J
authors.lastname: Huang
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Guolan
authors.initials: G
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Biological Sciences and NUS Centre for BioImaging Sciences, National University of Singapore, Singapore 117543.
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003.
authors.forename: Alice Y
authors.initials: AY
authors.lastname: Cheung
authors.affiliation: Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China lztao2005@scau.edu.cn.
authors.forename: Li-zhen
authors.initials: LZ
authors.lastname: Tao
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D016764:Cell Polarity / Q000187:drug effects / Q000235:genetics; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005966:Glucuronidase / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism* / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D021381:Protein Transport / Q000187:drug effects; D036226:Seedlings / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D012639:Seeds / Q000166:cytology / Q000187:drug effects / Q000196:embryology* / Q000235:genetics; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D049452:Green Fluorescent Proteins; D005966:Glucuronidase; D020558:GTP Phosphohydrolases; C000602507:ROP3 protein, Arabidopsis