Acclimation and interaction between drought and elevated UV-B in A. thaliana: Differences in response over treatment, recovery and reproduction

Authors


  • David Comont supported by an Aberystwyth University Ph.D. studentship to fund this research. Dylan Gwynn-Jones supported by UV4Growth Cost funding.

Correspondence

Dylan Gwynn-Jones, Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Ceredigion, SY23 3DA, WALES, UK. Tel: +44(0)1970 622318; Fax: +44(0)1970 622350; E-mail: dyj@aber.ac.uk

Abstract

Here, a factorial experiment was used to investigate the interactive effects of a UV-B episode and concurrent progressive drought on the growth, chemistry, and reproductive success of A. thaliana. Both drought and UV-B negatively affected rosette growth, although UV-B had the greater effect. Acclimation to UV-B involved adjustment of leaf morphology, while drought induced accumulation of soluble sugars and phenolics. All plants recovered from treatments, but the cost of recovery was a developmental delay resulting in alteration in phenological timings. Combined treatments interacted causing additive negative effects on growth following exposure. This may be linked with inhibition of soluble sugar accumulation by UV-B, restricting the capacity for osmotic adjustment in response to drought. Following cessation of treatments, relative growth rate (RGR) and net assimilation rate (NAR) were significantly stimulated in plants treated with combined drought and UV-B. This interaction alleviated subsequent impacts of elevated UV-B on silique yield and reproductive timings. This study demonstrates the potential for interaction between these two common environmental factors. Furthermore, it shows the changeable nature of these interactions over the course of exposure and recovery through to reproduction, highlighting the need for sustained assessment of such interactions over a plant's lifecycle.

Ancillary