International Network of Plant Abiotic Stress

Using Arabidopsis as model organism, many important genes in stress and ABA signaling have been identified. Nonetheless, we are only at the beginning of understanding the complexity of stress signaling pathways as numerous factors are coded by multigene families and implicated in cross-talk with other developmental, defense and hormonal pathways. It is also evident that ABA, salt and cold stress regulated gene expression is influenced by factors that are connected with chromatin remodeling, gene silencing, protein degradation and metabolic regulation. Research in WG2 therefore will use novel genetic approaches for identification and analysis of yet unknown factors that control ABA and stress-mediated regulation of transcription. These include:

WG2.1Thedevelopment of novel genetic approaches to identify yet unknown regulatory factors controlling salt, drought and cold tolerance and ABA signalling. Genetic screening strategies will be targeted to the isolation of mutants defective in abiotic-stress signalling pathways regulating proline or polyamine metabolism.

WG2.2 Analysis of cross-talk between stress signalling pathways using T-DNA mutants, RNAi silencing and cDNA overexpression approaches targeted to signalling factors, such as phospholipase D (PLD), aldehyde dehydrogenase (ALDH), MAP kinases, and different classes of transcription factors.

WG2.3 Study of involvement of subunits of plant SWI/SNF-type ATP dependent chromatin remodelling complexes in establishing the pattern of histone modifications during stress responses.

WG2.4 Identification and characterization of new signalling factors controlling cold-regulated transcription.

WG2.5 Identification of ABA-hypersensitive mutants using forward genetics. Generation of strong ABA-hypersensitive mutants by reverse genetics (i.e. triple loss-of-function mutants of PP2Cs, ABI1, ABI2, HAB1 and PP2CA). Identification of substrates of PP2C protein phosphatase HAB1 by protein-interaction studies.

WG2.6 Understanding the genetic and molecular nature of stress adaptation using Thellungiella halophyla and its close relative A. thaliana for comparison of stress responses in stress adapted and non-adapted species. Physiological responses to salt stress of T. halophyla and Arabidopsis will be compared to identify metabolites and metabolic pathways that are important for the adaptation to high salinity.

WG2.7 Development of new genetic tools for testing the functions of T. halophyla genes in Arabidopsis and study Thellungiella orthologs of Arabidopsis genes that are important in salt adaptation.