title: A temperature-sensitive allele of a putative mRNA splicing helicase down-regulates many cell wall genes and causes radial swelling in Arabidopsis thaliana.
abstract: The putative RNA helicase encoded by the Arabidopsis gene At1g32490 is a homolog of the yeast splicing RNA helicases Prp2 and Prp22. We isolated a temperature-sensitive allele (rsw12) of the gene in a screen for root radial swelling mutants. Plants containing this allele grown at the restrictive temperature showed weak radial swelling, were stunted with reduced root elongation, and contained reduced levels of cellulose. The role of the protein was further explored by microarray analysis. By using both fold change cutoffs and a weighted gene coexpression network analysis (WGCNA) to investigate coexpression of genes, we found that the radial swelling phenotype was not linked to genes usually associated with primary cell wall biosynthesis. Instead, the mutation has strong effects on expression of secondary cell wall related genes. Many genes potentially associated with secondary walls were present in the most significant WGCNA module, as were genes coding for arabinogalactans and proteins with GPI anchors. The proportion of up-regulated genes that possess introns in rsw12 was above that expected if splicing was unrelated to the activity of the RNA helicase, suggesting that the helicase does indeed play a role in splicing in Arabidopsis. The phenotype may be due to a change in the expression of one or more genes coding for cell wall proteins.
authors.affiliation: Plant Science Division, Research School of Biology, Australian National University, Canberra, 2601, Australia. pahowles@hotmail.com.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Howles
authors.affiliation: Plant Science Division, Research School of Biology, Australian National University, Canberra, 2601, Australia.|Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, 4072, Australia.
authors.forename: Leigh K
authors.initials: LK
authors.lastname: Gebbie
authors.affiliation: Plant Science Division, Research School of Biology, Australian National University, Canberra, 2601, Australia.|Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, 8041, New Zealand.
authors.forename: David A
authors.initials: DA
authors.lastname: Collings
authors.affiliation: Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, 8041, New Zealand.|Structural Biology Research Unit, Division of Medical Biochemistry, Department of Clinical Laboratory Sciences, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa.|Electron Microscope Unit, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa.|Department of Plant Pathology and Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32611, USA.
authors.forename: Arvind
authors.initials: A
authors.lastname: Varsani
authors.affiliation: Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, 8041, New Zealand.
authors.forename: Ronan C
authors.initials: RC
authors.lastname: Broad
authors.affiliation: Plant Science Division, Research School of Biology, Australian National University, Canberra, 2601, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Ohms
authors.affiliation: Plant Science Division, Research School of Biology, Australian National University, Canberra, 2601, Australia.
authors.forename: Rosemary J
authors.initials: RJ
authors.lastname: Birch
authors.affiliation: Plant Science Division, Research School of Biology, Australian National University, Canberra, 2601, Australia.
authors.forename: Ann H
authors.initials: AH
authors.lastname: Cork
authors.affiliation: Plant Science Division, Research School of Biology, Australian National University, Canberra, 2601, Australia.
authors.forename: Tony
authors.initials: T
authors.lastname: Arioli
authors.affiliation: Plant Science Division, Research School of Biology, Australian National University, Canberra, 2601, Australia.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Williamson
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D015536:Down-Regulation / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D009154:Mutation; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D013696:Temperature
chemical_list: D029681:Arabidopsis Proteins; D012333:RNA, Messenger; C000610377:At1g32490 protein, Arabidopsis; D020365:RNA Helicases
keywords: Arabidopsis thaliana; Cell expansion; Cell wall; RNA helicase; Radial swelling; mRNA splicing