title: Ups and downs of a transcriptional landscape shape iron deficiency associated chlorosis of the maize inbreds B73 and Mo17.
abstract: BACKGROUND
  Improving nutrient homeostasis is a major challenge of a sustainable maize cultivation, and cornerstone to ensure food supply for a growing world population. Although, iron constitutes an important nutrient, iron availability is limited. In this respect, iron deficiency associated chlorosis causes severe yield losses every year. Natural variation of the latter trait has yet not been addressed in maize and was therefore studied in the present analysis.
  
  
  RESULTS
  In this study, we i) report about the contrasting chlorosis phenotypes of the inbreds B73 and Mo17 at 10 and 300 μM iron regime, ii) identified over 400 significantly regulated transcripts (FDR < 0.05) within both inbreds at these growth conditions by deep RNA-Sequencing, iii) linked the gained knowledge with QTL information about iron deficiency related traits within the maize intermated B73 by Mo17 (IBM) population, and iv) highlighted contributing molecular pathways. In this respect, several genes within methionine salvage pathway and phytosiderophore synthesis were found to present constitutively high expression in Mo17, even under sufficient iron supply. Moreover, the same expression pattern could be observed for two putative bHLH transcription factors. In addition, a number of differentially expressed genes showed a co-localisation with QTL confidence intervals for iron deficiency related traits within the IBM population.
  
  
  CONCLUSIONS
  Our study highlights differential iron deficiency associated chlorosis between B73 and Mo17 and represents a valuable resource for differentially expressed genes upon iron limitation and chlorosis response. Besides identifying two putative bHLH transcription factors, we propose that methionine salvage pathway and sterol metabolism amongst others; underlie the contrasting iron deficiency related chlorosis phenotype of both inbreds. Altogether, this study emphasizes a contribution of selected genes and pathways on natural trait variation within the IBM population.
authors: Claude
authors: C
authors: Urbany
authors: Andreas
authors: A
authors: Benke
authors: Johanna
authors: J
authors: Marsian
authors: Bruno
authors: B
authors: Huettel
authors: Richard
authors: R
authors: Reinhardt
authors: Max Planck Institute for Plant Breeding Research, Quantitative Crop Genetics, 50829 Cologne, Germany. stich@mpipz.mpg.de.
authors: Benjamin
authors: B
authors: Stich
mesh_terms: D018506:Gene Expression Regulation, Plant; D063990:Gene Ontology; D056726:Genetic Association Studies; D007178:Inbreeding; D000090463:Iron Deficiencies; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics; D011110:Polymorphism, Genetic; D040641:Quantitative Trait Loci / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D059467:Transcriptome / Q000187:drug effects / Q000235:genetics; D003313:Zea mays / Q000235:genetics*
chemical_list: D012333:RNA, Messenger