title: Ecotypic differences in responses of Arabidopsis thaliana L. to elevated polychromatic UV-A and UV-B+A radiation in the natural environment: a positive correlation between UV-B+A inhibition and growth rate.
abstract: The effects of supplementary ultraviolet-A (UV-A) and ultraviolet-B+A (UV-B+A) in the natural environment on the growth and morphology of various ecotypes of Arabidopsis thaliana were investigated. The ecotypes investigated were Columbia (Col-4), Landsberg erecta (Ler-0), Cvi-0, Wassilewskija, Enkheim-D, Aa-0 and Di-1. The mutant hy-4 was also used. Results varied with the radiation treatment, ecotype and parameter measured. Plants subjected to elevated UV-A were both insensitive (all parameters Cvi-0 and Col-4) and sensitive. When responses to UV-A occurred they were mostly inhibitory (all significant responses of Di-1 and Enkheim-D, most parameters of Wassilewskija, and some parameters of hy-4), however, promotive affects were observed for some parameters of Aa-0 and Ler-0. Supplementary UV-B+A inhibited all parameters of Di-1 and Enkheim-D and most parameters of Col-4, Ler-0 and hy-4, but Wassilewskija, Aa-0 and Cvi-0 were mostly insensitive. The magnitude of the UV-B+A response varied with ecotype (compare Di-1 with Ler-0). Some ecotypes were sensitive to UV-A but not UV-B+A (Aa-0), whereas others (Ler-0, Col-4) show the opposite sensitivities. A linear relationship is reported between the degree of UV-B+A inhibition of each ecotype and growth rate. The higher the growth rate the more susceptible the ecotype is to UV-B+A inhibition. This relationship holds for the majority of growth parameters measured.
authors.affiliation: Institute of Biological Sciences, University of Aberystwyth, Credigon, Wales SY23 3DA, Aberystwyth, UK.
authors.forename: N M
authors.initials: NM
authors.lastname: Cooley
authors.forename: J T
authors.initials: JT
authors.lastname: Higgins
authors.forename: M G
authors.initials: MG
authors.lastname: Holmes
authors.forename: T H
authors.initials: TH
authors.lastname: Attridge
mesh_terms: D017360:Arabidopsis / Q000145:classification / Q000254:growth & development* / Q000528:radiation effects*; D017753:Ecosystem; D004781:Environmental Exposure; D010641:Phenotype; D011836:Radiation Tolerance / Q000235:genetics / Q000502:physiology*; D013045:Species Specificity; D014466:Ultraviolet Rays