ABSTRACT:

Dragonhead (Dracocephalummoldavica L.) isan annual, herbaceous plantof Lamiaceae and it has medicinal properties.Low temperature is one of the most important abiotic factors limiting growth, development, and distribution of plants. Polyamines such as Putrescine are small aliphatic low molecular weight polycationic nitrogenous compounds that are ubiquitous in higher plants. In this investigation study the role of Putrescine treatments (spray and root treatment) on physiological parameters on dragonhead under low temperature (12ºC). Experiments show that MDA and H2o2 accumulate under cold but Put treatments reduce it. Other parameters such as proline and photosynthetic pigments increased with put treatments under cold stress.