Differences in gene expression of drought-stress candidate genes across natural populations of Quercus pubescens Willd. in Italy. IUFRO 2012 Genetics of Fagaceae and Nothofagaceae. Poster abstracts. Bordeaux.

Understanding plant species acclimation and adaptation to climatic changes is one of the most interesting challenges at the interface of ecology, physiology and genetics. In this context, the investigation of functional genetic diversity related to stress tolerance of natural populations in a contrasting climatic context is a promising approach. Plant responses to drought stress are complex, involving a number of genes which contribute to drought adaptation. Here we use 30 candidate genes involved in drought-stress response in Q. robur (Brendel, Kremer, Le Provost, pers. com.). These candidate genes are involved in processes such as transpiration regulation, stomatal development, stomatal light response, cuticle biosynthesis, and water use efficiency. We tested for differential gene expression in natural populations of Quercus pubescens Willd. at mesic and xeric sites in Central and Southern Italy. For this purpose, RNA was extracted from leaf material of 100 individuals. We aimed to identify markers for climatic acclimation and adaptation of natural populations. Results of SIMPER analysis for dissimilarity revealed that four out of 30 candidate genes appear as main factors which differentiate the samples. In detail, significant differences in gene expression were most obvious between the most mesic (central Italy) compared to the most xeric (S Italy) site. It will be a challenge for future research to tackle if these markers reappear in the droughtstress response in other tree species or plants in general.