title: Identification of drought tolerance determinants by genetic analysis of root response to drought stress and abscisic Acid.
abstract: Drought stress is a common adverse environmental condition that seriously affects crop productivity worldwide. Due to the complexity of drought as a stress signal, deciphering drought tolerance mechanisms has remained a major challenge to plant biologists. To develop new approaches to study plant drought tolerance, we searched for phenotypes conferred by drought stress and identified the inhibition of lateral root development by drought stress as an adaptive response to the stress. This drought response is partly mediated by the phytohormone abscisic acid. Genetic screens using Arabidopsis (Arabidopsis thaliana) were devised, and drought inhibition of lateral root growth (dig) mutants with altered responses to drought or abscisic acid in lateral root development were isolated. Characterization of these dig mutants revealed that they also exhibit altered drought stress tolerance, indicating that this root response to drought stress is intimately linked to drought adaptation of the entire plant and can be used as a trait to access the elusive drought tolerance machinery. Our study also revealed that multiple mechanisms coexist and together contribute to whole-plant drought tolerance.
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA. lxiong@danforthcenter.org
authors.forename: Liming
authors.initials: L
authors.lastname: Xiong
authors.forename: Rui-Gang
authors.initials: RG
authors.lastname: Wang
authors.forename: Guohong
authors.initials: G
authors.lastname: Mao
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Koczan
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003890:Desiccation; D004190:Disasters; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D008353:Mannitol; D009154:Mutation; D018517:Plant Roots / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D014882:Water-Electrolyte Balance
chemical_list: D029681:Arabidopsis Proteins; D008353:Mannitol; D000040:Abscisic Acid