QTL analysis for sugar-regulated leaf senescence supports flowering-dependent and -independent senescence pathways.
*The aim of this work was to determine the genetic basis of sugar-regulated senescence and to explore the relationship with other traits, including flowering and nitrogen-use efficiency. *Quantitative trait loci (QTLs) for senescence were mapped in the Arabidopsis Bay-0 x Shahdara recombinant-inbred line (RIL) population after growth on glucose-containing medium, which accelerates senescence. The extent of whole-rosette senescence was determined by imaging the maximum quantum yield of photosystem II (F(v)/F(m)). *A major QTL on the top of chromosome 4 colocalized with FRI, a major determinant of flowering. This QTL interacted epistatically with a QTL on chromosome 5, where the floral repressor FLC localizes. Vernalization accelerated senescence in late-flowering lines with functional FRI and FLC alleles. Comparison with previous results using the Bay-0 x Shahdara population showed that rapid rosette senescence on glucose-containing medium was correlated with early flowering and high sugar content in compost-grown plants. In addition, correlation was found between the expression of flowering and senescence-associated genes in Arabidopsis accessions. However, an additional QTL on chromosome 3 was not linked to flowering, but to nitrogen-use efficiency. *The results show that whole-rosette senescence is genetically linked to the vernalization-dependent control of flowering, but is also controlled by flowering-independent pathways.
Wingler
Astrid
A
Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK. a.wingler@ucl.ac.uk
Purdy
Sarah Jane
SJ
Edwards
Sally-Anne
SA
Chardon
Fabien
F
Masclaux-Daubresse
Céline
C
D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D016922:Cellular Senescence / Q000235:genetics* / Q000502:physiology; D002875:Chromosomes; D004843:Epistasis, Genetic; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D017343:Genes, Plant; D005947:Glucose / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000502:physiology; D018515:Plant Leaves / Q000235:genetics* / Q000502:physiology; D040641:Quantitative Trait Loci
D045332:Photosystem II Protein Complex; D005947:Glucose; D009584:Nitrogen