Focus of Research

Functional analysis of a calcium sensor protein/serine-threonine kinase signaling network

Calcium signals regulate a wide range of biological responses to external stimuli as well as many physiological processes in plants. The proposed project aims to continue to comprehensively explore the mechanisms of a novel calcium signaling system from Arabidopsis thaliana. This system comprises a group of protein kinases (AtCIPKs), which interact with Calcineurin B-like calcium sensor proteins (AtCBLs). In general, this project is focused on the functional characterization of this CBL-CIPK interaction network and its contribution to integrate and specifically decode various calcium signals in plant cells. The proposed research for the requested funding period is focused on the following main objectives:

  1. Continuation of the molecular characterization of the CBL and CIPK protein families by analyzing their expression, sub-cellular localization, interaction specificity and their biochemical properties.
  2. The identification of the specific physiological processes regulated by the different calcium sensor/kinase complexes by the detailed phenotypical and molecular characterization of mutant lines, which have been isolated during the first period of funding.
  3. Identification of target proteins by means of yeast interaction assays.

A systems biological approach to understanding the control of specificity in Ca2+-signaling systems

The fact that Ca2+ is a ubiquitous intracellular regulator in signaling pathways raises the important issue of how response specificity is controlled in Ca2+-based signaling systems. We have assembled a multidisciplinary team to take a systems biological approach to investigating this issue. The work will focus on Arabidopsis guard cells as a model because it is a well-characterized system with robust and easily measured outputs. We shall investigate the role of the Ca2+ sensor (CBL)/protein kinase (CIPK) module (comprising 10 CBLs and 26 CIPKs) for interpreting and decoding stimulus induced increases in Ca2+. To do this we shall employ a combination of modeling and genetic manipulation to investigate how specific Ca2+ signals are perceived and interpreted by unique combinations of CBL/CIPK components. We shall use the results from biological experiments to inform model assembly and test hypotheses generated from modeling by experimental manipulation. The results of this work will have major implications for understanding the fundamentals of Ca2+-based signaling in all organisms.

Stress adaption in tomato

Tomato (Solanum lycopersicum) is the most important vegetable fruit worldwide. However, sustainable production, pleasant taste and – if somehow possible – beneficial health effects are now becoming top consumer priorities and represent key aspects of a sustainable economy in the long term. Moreover, salt, drought and temperature stresses dramatically impact on potentially achievable yields of currently available crop varieties. In particular for tomato , a major vegetable for healthy human nutrition, salinization, as a result of natural conditions or irrigation activity, diminishes yields and results in dramatic economic damages. In cooperation with research groups from Brasil, USA, Israel and Palestine we combine most innovative molecular and biotechnology approaches to create tomato crops with imporved yield under stress conditions and an enhanced content of beneficial compounds.

International Cooperations