title: Arabidopsis thaliana mutant lpsi reveals impairment in the root responses to local phosphate availability.
abstract: Phosphate (Pi) deficiency triggers local Pi sensing-mediated inhibition of primary root growth and development of root hairs in Arabidopsis (Arabidopsis thaliana). Generation of activation-tagged T-DNA insertion pools of Arabidopsis expressing the luciferase gene (LUC) under high-affinity Pi transporter (Pht1;4) promoter, is an efficient approach for inducing genetic variations that are amenable for visual screening of aberrations in Pi deficiency responses. Putative mutants showing altered LUC expression during Pi deficiency were identified and screened for impairment in local Pi deficiency-mediated inhibition of primary root growth. An isolated mutant was analyzed for growth response, effects of Pi deprivation on Pi content, primary root growth, root hair development, and relative expression levels of Pi starvation-responsive (PSR) genes, and those implicated in starch metabolism and Fe and Zn homeostasis. Pi deprived local phosphate sensing impaired (lpsi) mutant showed impaired primary root growth and attenuated root hair development. Although relative expression levels of PSR genes were comparable, there were significant increases in relative expression levels of IRT1, BAM3 and BAM5 in Pi deprived roots of lpsi compared to those of the wild-type. Better understanding of molecular responses of plants to Pi deficiency or excess will help to develop suitable remediation strategies for soils with excess Pi, which has become an environmental concern. Hence, lpsi mutant will serve as a valuable tool in identifying molecular mechanisms governing adaptation of plants to Pi deficiency.
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907-1165, USA.
authors.forename: Athikkattuvalasu S
authors.initials: AS
authors.lastname: Karthikeyan
authors.affiliation: National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute, New Delhi 110012, India.
authors.forename: Ajay
authors.initials: A
authors.lastname: Jain
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907-1165, USA.
authors.forename: Vinay K
authors.initials: VK
authors.lastname: Nagarajan
authors.affiliation: Department of Biology, Western Kentucky University, Bowling Green, KY 42101-1080, USA.
authors.forename: Bhaskaran
authors.initials: B
authors.lastname: Sinilal
authors.affiliation: Department of Biology, Western Kentucky University, Bowling Green, KY 42101-1080, USA.
authors.forename: Shivendra V
authors.initials: SV
authors.lastname: Sahi
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907-1165, USA. Electronic address: kraghoth@purdue.edu.
authors.forename: Kashchandra G
authors.initials: KG
authors.lastname: Raghothama
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D017343:Genes, Plant; D009154:Mutation; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000172:deficiency / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D027682:Cation Transport Proteins; C099651:IRT1 protein, Arabidopsis; D010710:Phosphates; D010758:Phosphorus; C581880:BAM3 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases
keywords: Activation-tagged T-DNA insertion; Arabidopsis thaliana; Local Pi sensing; Phosphate deficiency; Pht1;4-LUC; lpsi mutant