List of Articles TpGAS Open Access Article Abstract Page Full-Text 1 - The effect of different levels of drought stress in greenhouse condition on the expression of Germacron A synthase (TpGAS) and Parthenolide synthetase (TpPTS) genes involved in the production of Parthenolide in Tanacetum parthenium L. Seyyedeh Samaneh Mosavi Khorshidi