Integrative functional genomics of salt acclimatization in the model legume Lotus japonicus.
The model legume Lotus japonicus was subjected to non-lethal long-term salinity and profiled at the ionomic, transcriptomic and metabolomic levels. Two experimental designs with various stress doses were tested: a gradual step acclimatization and an initial acclimatization approach. Ionomic profiling by inductively coupled plasma/atomic emission spectrometry (ICP-AES) revealed salt stress-induced reductions in potassium, phosphorus, sulphur, zinc and molybdenum. Microarray profiling using the Lotus Genechip allowed the identification of 912 probesets that were differentially expressed under the acclimatization regimes. Gas chromatography/mass spectrometry-based metabolite profiling identified 147 differentially accumulated soluble metabolites, indicating a change in metabolic phenotype upon salt acclimatization. Metabolic changes were characterized by a general increase in the steady-state levels of many amino acids, sugars and polyols, with a concurrent decrease in most organic acids. Transcript and metabolite changes exhibited a stress dose-dependent response within the range of NaCl concentrations used, although threshold and plateau behaviours were also observed. The combined observations suggest a successive and increasingly global requirement for the reprogramming of gene expression and metabolic pathways to maintain ionic and osmotic homeostasis. A simple qualitative model is proposed to explain the systems behaviour of plants during salt acclimatization.
Max Planck Institute for Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, Potsdam-Golm, D-14476, Germany.
Diego H
DH
Sanchez
Felix
F
Lippold
Henning
H
Redestig
Matthew A
MA
Hannah
Alexander
A
Erban
Ute
U
Krämer
Joachim
J
Kopka
Michael K
MK
Udvardi
D000064:Acclimatization / Q000187:drug effects* / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D016147:Genes, Tumor Suppressor; D018745:Genome, Plant / Q000235:genetics*; D023281:Genomics; D000070116:Lotus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D009687:Nuclear Proteins; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development; D040081:Protein Array Analysis; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects; D015854:Up-Regulation
C403503:FAM107A protein, human; D009687:Nuclear Proteins; D010940:Plant Proteins; D018749:RNA, Plant; D012965:Sodium Chloride