title: Metabolite Profiling of Low-P Tolerant and Low-P Sensitive Maize Genotypes under Phosphorus Starvation and Restoration Conditions.
abstract: BACKGROUND
  Maize (Zea mays L.) is one of the most widely cultivated crop plants. Unavoidable economic and environmental problems associated with the excessive use of phosphatic fertilizers demands its better management. The solution lies in improving the phosphorus (P) use efficiency to sustain productivity even at low P levels. Untargeted metabolomic profiling of contrasting genotypes provides a snap shot of whole metabolome which differs under specific conditions. This information provides an understanding of the mechanisms underlying tolerance to P stress and the approach for increasing P-use-efficiency.
  
  
  RESULTS
  A comparative metabolite-profiling approach based on gas chromatography-mass spectrometry (GC/MS) was applied to investigate the effect of P starvation and its restoration in low-P sensitive (HM-4) and low-P tolerant (PEHM-2) maize genotypes. A comparison of the metabolite profiles of contrasting genotypes in response to P-deficiency revealed distinct differences among low-P sensitive and tolerant genotypes. Another set of these genotypes were grown under P-restoration condition and sampled at different time intervals (3, 5 and 10 days) to investigate if the changes in metabolite profile under P-deficiency was restored. Significant variations in the metabolite pools of these genotypes were observed under P-deficiency which were genotype specific. Out of 180 distinct analytes, 91 were identified. Phosphorus-starvation resulted in accumulation of di- and trisaccharides and metabolites of ammonium metabolism, specifically in leaves, but decreased the levels of phosphate-containing metabolites and organic acids. A sharp increase in the concentrations of glutamine, asparagine, serine and glycine was observed in both shoots and roots under low-P condition.
  
  
  CONCLUSIONS
  The new insights generated on the maize metabolome in response to P-starvation and restoration would be useful towards improvement of the P-use efficiency in maize.
authors.affiliation: Department of Botany, Faculty of Science, Hamdard University, New Delhi, 110062, India.
authors.forename: Arshid Hussain
authors.initials: AH
authors.lastname: Ganie
authors.affiliation: Department of Botany, Aligarh Muslim University, Aligarh, 202002, India.
authors.forename: Altaf
authors.initials: A
authors.lastname: Ahmad
authors.affiliation: Division of Plant Physiology, Indian Agricultural Research Institute, New Delhi, 110012, India.
authors.forename: Renu
authors.initials: R
authors.lastname: Pandey
authors.affiliation: Department of Plant Production, College of Food and Agricultural Science, P.O. Box 2460, King Saud University, Riyadh, 11451, Saudi Arabia.
authors.forename: Ibrahim M
authors.initials: IM
authors.lastname: Aref
authors.affiliation: Department of Botany, Faculty of Science, Hamdard University, New Delhi, 110062, India.
authors.forename: Peerzada Yasir
authors.initials: PY
authors.lastname: Yousuf
authors.affiliation: Department of Pharmacognosy & Pharmaceutical Chemistry, Faculty of Pharmacy, Jamia Hamdard, New Delhi, 110062, India.
authors.forename: Sayeed
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Department of Botany, Faculty of Science, Hamdard University, New Delhi, 110062, India.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Iqbal
mesh_terms: D000220:Adaptation, Biological; D016000:Cluster Analysis; D005838:Genotype; D055442:Metabolome; D055432:Metabolomics / Q000379:methods; D010758:Phosphorus / Q000172:deficiency / Q000378:metabolism; D013312:Stress, Physiological; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D010758:Phosphorus