Improving the material potential of oats by promoting exodermal development

Abstract

In recent years the world of science and design have been captivated by biomaterials. Now a new material has entered the stage: materials created from the roots of plants. Avena sativa has proven to have excellent material properties, mainly because of its rapid root development and architecture. However, currently these root-grown materials made from oats lack the mechanical strength to be considered as a proper material. The key to enhancing the biomaterial potential of oats lies in promoting the exodermal development. Biopolymers suberin and lignin contribute to the structural stability of roots and by increasing their abundance, increasing the tensile strength might be achieved. The stress hormone abscisic acid (ABA) is known to play a role in the synthesis of the exodermis. This research aims to map the ABA-suberin-lignin interplay in oats, potentially bolstering root strength. Besides manual application of ABA, this research will also explore the natural response of the exodermis to stress conditions. Drought and salt stress are known to correspond with the synthesis of ABA and are therefore included as a treatment. In addition, the effect of silica on the mechanical strength of oat roots is tested, since silica is known to contribute to the stability of grasses and improve Casparian band formation. ABA appeared to have an effect on the exodermal development of A. sativa, A. strigosa and A. sterilis. When being treated with salt or drought stress A. sativa did not develop an exodermis, nor did it have an effect on the endodermis. However, when treated with both ABA and silica A. sativa showed strong increase in endodermal lignin and exodermal suberin. Therefore, it was expected that treatment of the root-based material would improve the mechanical strength of oats. However, results of the materials did not test positive for improvement of the root tensile strength when receiving different treatments. No correlation could be found between the exodermal development of oats and changes in tensile strength increase.