Improving restoration of native habitats: DELLA response plasticity in Arabidopsis thaliana as an approach for defining appropriate genotypes for stressful conditions

The emerging field of restoration genetics has contributed to recent advances in procuring genetically appropriate plant material for restoration projects. In many cases, finding suitable local genotypes to rehabilitate degraded lands is costly or difficult. A consideration of plant phenotypic plasticity is proposed for restoration practice as it may provide a sustainable, cost-effective alternative to relying on “local” seed sources. For example, DELLA protein induction represses gibberellin signaling during stressful conditions. Studies have suggested that DELLAs allow appropriate plastic modulation of plant growth in response to environmental stress typical of many restoration sites. A conceptual approach to the value of plasticity would include wild type and DELLA quadruple mutant strains of Arabidopsis thaliana in different soil treatments that represent a wide soil gradient. Soil variants could include texture, moisture, bulk density, salinity, pH, nutrients, and presence of contaminants. Plant measurements to establish this alternative genetic tool could include height, area, number of flowers, number of seeds, and seed weight. Along the stress gradient, if DELLA wild type has increased fitness over DELLA mutants in the more stressed conditions due to increased salinity, contaminants, and disturbance typical of those areas, the value of plasticity would be supported. This experimental approach is a basis for empirical evidence that restoration practice should emphasize growth plasticity to ensure persistence of ecologically restored populations in highly stressed or heterogeneous conditions.