title: Organ-specific phosphorus-allocation patterns and transcript profiles linked to phosphorus efficiency in two contrasting wheat genotypes.
abstract: Recent studies have identified genotypic variation in phosphorus (P) efficiency, but rarely have the underlying mechanisms been described at the molecular level. We demonstrate that the highly P-efficient wheat (Triticum aestivum L.) cultivar Chinese 80-55 maintains higher inorganic phosphate (Pi ) concentrations in all organs upon Pi withdrawal in combination with higher Pi acquisition in the presence of Pi when compared with the less-efficient cultivar Machete. These findings correlated with differential organ-specific expression of Pi transporters TaPHT1;2, TaPHT1;5, TaPHT1;8, TaPHT2;1 and H(+) -ATPase TaHa1. Observed transcript level differences between the cultivars suggest that higher de novo phospholipid biosynthetic activities in Pi -limited elongating basal leaf sections are another crucial adaptation in Chinese 80-55 for sustaining growth upon Pi withdrawal. These activities may be supported through enhanced breakdown of starch in Chinese 80-55 stems as suggested by higher TaGPho1 transcript levels. Chinese 80-55 fine roots on the other hand show strong suppression of transcripts involved in glycolysis, transcriptional regulation and ribosomal activities. Our work reveals major differences in the way the two contrasting cultivars allocate Pi and organic P compounds between source and sink tissues and in the acclimation of their metabolism to changes in Pi availability.
authors.affiliation: School of Plant Biology, The University of Western Australia, Perth, Western Australia, 6009, Australia; Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, 38040, Pakistan.
authors.forename: Tariq
authors.initials: T
authors.lastname: Aziz
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Finnegan
authors.forename: Hans
authors.initials: H
authors.lastname: Lambers
authors.forename: Ricarda
authors.initials: R
authors.lastname: Jost
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005838:Genotype; D008954:Models, Biological; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D010743:Phospholipids / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism* / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects; D017494:Proton Pumps / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects; D014908:Triticum / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*
chemical_list: D010743:Phospholipids; D010940:Plant Proteins; D017494:Proton Pumps; D012333:RNA, Messenger; D010758:Phosphorus; D002244:Carbon
keywords: genetic variation; glycolysis; nutrients/other; phosphate transport; phosphocholine; transcription and translation; transcriptome