title: White lupin cluster root acclimation to phosphorus deficiency and root hair development involve unique glycerophosphodiester phosphodiesterases.
abstract: White lupin (Lupinus albus) is a legume that is very efficient in accessing unavailable phosphorus (Pi). It develops short, densely clustered tertiary lateral roots (cluster/proteoid roots) in response to Pi limitation. In this report, we characterize two glycerophosphodiester phosphodiesterase (GPX-PDE) genes (GPX-PDE1 and GPX-PDE2) from white lupin and propose a role for these two GPX-PDEs in root hair growth and development and in a Pi stress-induced phospholipid degradation pathway in cluster roots. Both GPX-PDE1 and GPX-PDE2 are highly expressed in Pi-deficient cluster roots, particularly in root hairs, epidermal cells, and vascular bundles. Expression of both genes is a function of both Pi availability and photosynthate. GPX-PDE1 Pi deficiency-induced expression is attenuated as photosynthate is deprived, while that of GPX-PDE2 is strikingly enhanced. Yeast complementation assays and in vitro enzyme assays revealed that GPX-PDE1 shows catalytic activity with glycerophosphocholine while GPX-PDE2 shows highest activity with glycerophosphoinositol. Cell-free protein extracts from Pi-deficient cluster roots display GPX-PDE enzyme activity for both glycerophosphocholine and glycerophosphoinositol. Knockdown of expression of GPX-PDE through RNA interference resulted in impaired root hair development and density. We propose that white lupin GPX-PDE1 and GPX-PDE2 are involved in the acclimation to Pi limitation by enhancing glycerophosphodiester degradation and mediating root hair development.
authors.affiliation: Department of Plant Nutrition, China Agricultural University, Key Laboratory of Plant-Soil Interactions, Beijing 100193, People's Republic of China.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Cheng
authors.forename: Bruna
authors.initials: B
authors.lastname: Bucciarelli
authors.forename: Junqi
authors.initials: J
authors.lastname: Liu
authors.forename: Kelly
authors.initials: K
authors.lastname: Zinn
authors.forename: Susan
authors.initials: S
authors.lastname: Miller
authors.forename: Jana
authors.initials: J
authors.lastname: Patton-Vogt
authors.forename: Deborah
authors.initials: D
authors.lastname: Allan
authors.forename: Jianbo
authors.initials: J
authors.lastname: Shen
authors.forename: Carroll P
authors.initials: CP
authors.lastname: Vance
mesh_terms: D000064:Acclimatization / Q000187:drug effects / Q000502:physiology*; D003624:Darkness; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology; D057075:Enzyme Assays; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D031297:Lupinus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017905:Phosphites / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D010758:Phosphorus / Q000172:deficiency* / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D017905:Phosphites; D010940:Plant Proteins; D012333:RNA, Messenger; D010758:Phosphorus; D010727:Phosphoric Diester Hydrolases; C038133:glycerophosphodiester phosphodiesterase