A decrease in growth rates can partly or totally be compensated for by an increase in duration of development in Arabidopsis thaliana plants subjected to various environmental conditions.

GRANIER C; COOKSON, S,; AGUIRREZABAL L; CHENU K; SIMONNEAU, T; F. TARDIEU

. University of Sheffield

Workshop; . Plant Frontier Meeting – session: Phenotypic plasticity and the changing environment. University of Sheffield; 2005

A decrease in growth rates can partly or totally be compensated for by an increase in duration of development in Arabidopsis thaliana plants subjected to various environmental conditions. C. Granier1, S. Cookson1, L. Aguirrezabal1,2, K. Chenu1, T. Simonneau1  and F. Tardieu1 Generally plants response to abiotic stresses by a reduction in final leaf area. This has essentially been attributed to a reduction in leaf expansion and cell division rates, whilst the number of leaves and the duration of leaf expansion are often considered to be only slightly affected (Granier and Tardieu, 1999a&b, Lecoeur et al., 1995). Tools, methodological concepts and automation were developed in our group to analyse quantitatively the leaf development and its response to various environmental conditions in Arabidopsis thaliana. The natural occurring genetic variability of Arabidopsis thaliana and a collection of leaf development mutants were used to compare stress responses in different genetic backgrounds. The environmental conditions studied were reductions in temperature, day-length, incident light or soil water content. For individual leaf development decreasing temperature, day-length, incident light or soil water content caused a decrease in leaf expansion rate which was partly or totally compensated for by an increase in the duration of leaf expansion. Superimposed upon this at the whole plant level, these treatments caused a decrease in leaf initiation and emergence rates which was partly or totally compensated for by an increase in the duration of the phase during which leaves were initiated on the apex. These compensation processes observed at both whole-plant and individual leaf levels were observed in all ecotypes but differed in their magnitude. The responses of different genotypes to environmental conditions have the potential to reveal some of the components of the genetic variability associated with the adaptation of growth to environmental conditions.