title: Natural variation of Arabidopsis root architecture reveals complementing adaptive strategies to potassium starvation.
abstract: Root architecture is a highly plastic and environmentally responsive trait that enables plants to counteract nutrient scarcities with different foraging strategies. In potassium (K) deficiency (low K), seedlings of the Arabidopsis (Arabidopsis thaliana) reference accession Columbia (Col-0) show a strong reduction of lateral root elongation. To date, it is not clear whether this is a direct consequence of the lack of K as an osmoticum or a triggered response to maintain the growth of other organs under limiting conditions. In this study, we made use of natural variation within Arabidopsis to look for novel root architectural responses to low K. A comprehensive set of 14 differentially responding root parameters were quantified in K-starved and K-replete plants. We identified a phenotypic gradient that links two extreme strategies of morphological adaptation to low K arising from a major tradeoff between main root (MR) and lateral root elongation. Accessions adopting strategy I (e.g. Col-0) maintained MR growth but compromised lateral root elongation, whereas strategy II genotypes (e.g. Catania-1) arrested MR elongation in favor of lateral branching. K resupply and histochemical staining resolved the temporal and spatial patterns of these responses. Quantitative trait locus analysis of K-dependent root architectures within a Col-0 × Catania-1 recombinant inbred line population identified several loci each of which determined a particular subset of root architectural parameters. Our results indicate the existence of genomic hubs in the coordinated control of root growth in stress conditions and provide resources to facilitate the identification of the underlying genes.
authors: Plant Science Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors: Fabian
authors: F
authors: Kellermeier
authors: Fabien
authors: F
authors: Chardon
authors: Anna
authors: A
authors: Amtmann
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D017360:Arabidopsis / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D016923:Cell Death / Q000187:drug effects; D003433:Crosses, Genetic; D014644:Genetic Variation; D005838:Genotype; D007178:Inbreeding; D018519:Meristem / Q000166:cytology / Q000187:drug effects; D010641:Phenotype; D018517:Plant Roots / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D040641:Quantitative Trait Loci / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics
chemical_list: D011188:Potassium