Systems performance of crops under drought stress
The aim of WP1 is to investigate the complex interactions between molecular pathways of signalling drought stress and those controlling cell and organ growth and to compare the responses of selected clones at different levels of complexity from the cell to tissue quality and plant architecture. There is variation between clones in the allocation of biomass to roots. The expected trade-off is lower aboveground biomas (wood) production. Because of the wide natural range of poplar in particular, ecotypes with adaptation to wet and dry habitats are found. We are exploiting these different adaptation strategies to investigate the molecular basis of traits involved in adaptation to drought-stressed environments and to explore the range of acclimation by studying genotypes with contrasting drought tolerance. This provides knowledge on key pathways and their potential regulators as a basis to selecting poplar that can maintain high biomass production under mild drought stress or genotypes that will survive severe drought spells with low trade-off in biomass production when water is not scarce. The process of wood formation competes with root or leaf formation. Therefore, it is crucial to understand plant internal allocation processes of carbon to different sinks, including defence compounds and volatiles.
Preparing the field site at Savigliano in northern Italy where 6,000 trees representing 672 poplar clones are tested for tolerance to drought
A similar approach is being taken to investigate key regulators in miscanthus and arundo in a set of core material subjected to moderate, but highly controlled drought stress as well as strong stress. The core experiments are complemented by a set of in-depth studies related to signalling with the overarching goal to dissect molecular pathways at tissue and cellular level.
The core experiments examine the response of a number of clones of poplar (4), miscanthus (5) and arundo (2) to drought stress. They are each grown under three levels of stress in the field. In addition to monitoring growth, photosynthesis and water use, the research is examining the transcriptome (RNA-Seq.) to identify genes that play a role particularly in drought response. In addition, we are examing effects on secondary metabolites and wood properties in poplar.
The glasshouse experiment at INRA (Nancy) examining the response of poplar to drought
Complementing the core experiments grown in the field, 6 satellite experiments are being conducted under heavily controlled greenhouse conditions. These are examining hormone kenetics, root growth, stomatal regulation and isoprene emissions.