International experts working on the analysis of plant tolerance were gathered in Tunis, from 22 to 24 March 2007, at a scientific workshop ‘Abiotic stresses in legumes’. This was organised at the initiative of the European Grain Legumes Integrated Project (
GLIP) (Workpackages 4.1 and 8.1), as a satellite meeting of the Model Legumes Congress 2007.
This 3-days workshop mixed genomics and physiological talks on “Abiotic stresses in legumes” but also included some non-legume plants talks to learn from other experience and knowledge. The workshop enabled the participants to discuss the best strategies that lead from genomic data to establish their physiological function. This workshop included formal talks, poster sessions as well as informal interactions and discussion. Apart from the direct scientific significance of this meeting, a main purpose was to gather the competences and a critical mass of legume researchers to exploit all tools and resources developed in GLIP for this specific topic of abiotic stress responses.
Echos from the workshop
Basic scientists, molecular biologists, genomicists, physiologists and agronomists involved in several ongoing EU projects were present together with representatives of international agricultural organisations. Legume experts and their colleagues working on non-legume plants came together so as to learn from a variety of stress response models: agronomic, eco-physiological and genomic models.
Maintaining or improving crop productivity under conditions of abiotic constraint in the field is one major concern in many areas in the world where legumes are grown. Abiotic stresses refer to different environmental factors: water deficit, high temperatures, saline stress, mineral deficiency, frost, chilling, and others, which can occur at different levels and development stages.
The whole plant approach allows key variables of the plant/genotype interaction that maintains yield under stress to be assessed. Environmental signals and plant physiological mechanisms activated at different growth stages can be useful to determine their hierarchy and relevance in the physiological processes involved. Adapted agronomic management techniques are needed to cope with abiotic stresses in the field. However, modelling the eco-physiological interactions between plants and the environment, considering the particular aspects of legume physiology, will enhance the basic understanding of mechanisms for further agronomic improvement.
In legumes, the symbiotic bacterial partner, the rhizobium, and other components of the rhizosphere have key roles in the agronomic performance of these crops, and should be taken into account in the analysis of plant response. Improving symbiosis under stress conditions will contribute to the development and use of legumes as pioneering crops since dry or saline soils are also poor under combined nitrogen.
Parallel development of genomic approaches will reveal molecular mechanisms involved in the regulation of the plant physiological responses. Exploiting the data obtained for different plant species (particularly different legumes) will highlight key molecules and genes involved in stress responses. These approaches should evolve from the initial description level under specific conditions to more elaborate screenings defining traits and genes involved in crop adaptation strategies. Targeted crop strategies should focus on the enhancement of tolerance to abiotic stress during grain filling or on rapid soil coverage in specific systems by controlling germination potential and initial root growth.
In addition, exploiting genetic diversity is crucial to obtain both contrasted types and sources of tolerances. Genetic resources are in fact mutants already selected by specific environmental conditions, possibly making them more suitable for field conditions than laboratory mutants.
Integrating molecular and genetic data into eco-physiological models are required in order to define the regulatory mechanisms involved in the control of plant growth and development under abiotic stress constraints and to create novel elite cultivars. This will bring new perspectives to the development of novel crop management techniques and to the identification of crucial breeding targets.
Source: M. Crespi and A. Schneider.
News
