Title : Application of exogenous synthetic strigolactone GR24 on in vitro Medicago truncatula plants with modified auxin transport in conditions of phosphate deficiency and excess
One of the most important nutrients required for normal development of plants is phosphorus. Both phytohormones auxin and strigolactones participate in the plant response associated with the phosphate signaling. In terms of phosphorus starvation, plants have developed mechanisms for overcoming stress, expressed in the formation of shortened and thickened cluster roots. Medicago truncatula plants with overexpression and downregulation of MtLAX3 gene (involved in polar auxin transport), transcriptional reporters of MtLAX3 (expressing reporter genes GUS and GFP under control of LAX promoter) and wild type plants were in vitro cultivated in extreme conditions of phosphate deficiency and excess. Phenotypic characterization and morphometric measurements were performed for the root system before and after treatment with synthetic strigolactone GR24. The relative transcript level of MtLAX3 and MtMAX2 (involved in the strigolactone signaling) was measured. The expression of GUS reporter gene fused to MtLAX3 promoter was traced in different organs and tissues by histochemical GUS assay.