Plant roots present an enormous interspecific phenotypic variation, mostly because roots largely contribute adaptation to different kind of soils. Fundamental to adaptation is the root cortex, a specialized tissue located between the epidermis and the vascular tissue, which acts to regulate air supply to the growing root tip and to store nutrients in plants growing in adverse weather and nutritive conditions (1). The number of cortical layers varies among species, but the molecular basis underlying this variability and its role in plant adaptation to diverse environmental conditions is still not well understood. Hence, to deepen knowledge on the contribution of the cortical layer number to plant fitness is essential for shading light on the mechanisms enabling adaptation to ecological niches.
Aims of this project are:
a) To unveil the molecular mechanisms controlling cortical layer number in plants.
b) To study whether to increase cortical layers enhances plant fitness under stress conditions.
To reach the proposed objectives it will be used a strategy of cutting-edge molecular biology and genomic techniques.
The results of this proposal will have a double impact:
A. Conceptual;
B. Applied;
A. Conceptual impact (evo-devo):
The expected results of this research will help to elucidate a critical aspect in the evolution and adaptation of land plants, focusing on the molecular and genetic mechanisms that lead to a diversification in root anatomy. By identifying the molecular basis that governs multiple cortical layer formation, we aim to understand the contribution given by the variability of cortical layers to plant adaptation to their niches. Our results will elucidate the biological significance of inter-specific cortical layer number variability for the first time. In a broader contest, our research will provide evidences about the biological meaning of inter-species anatomical variability.
B. Applied impact:
The results we are aiming at will allow gaining knowledge and control of the regulatory circuits governing cortex anatomy, an important adaptive trait in land plants. As effect of global warming, many areas begin to experience different weather and climate patterns such as dry lands and frequent flooding. In many dry land areas, the climate is become even more arid and rivers, lakes and underground water sources are drying up. It is estimated that about one third of all global agricultural land is either highly or moderately degraded. Via the modulation of only one trait (the root cortex) we aim to generate plants that are able to grow in dry lands, salty soils. Possibly, we aim to export the knowledge acquired in Cardamine hirsuta also in highly cultivated crop species such as rice (Oryza sativa, radicle 4 cortical layers), turnip (Brassica rapa, 2 cortical layers), barley ( Hordeum vulgaris, 4 cortical layers) and tomato (Solanum lycopersicum, 3 cortical layers) to produce varieties of those species with increased cortical layer number that will be possible to grow in particularly disturbed soils.