Effect of exogenous application of IAA and GA(3)on growth, protein content, and antioxidant enzymes ofSolanum tuberosumL. grownin vitrounder salt stress

摘要

Indole-3-acetic acid (IAA) and gibberellic acid (GA(3)) are essential for the growth and development of plants. In the present study, the ameliorative potential of these phytohormones on growth, protein content, and antioxidant enzymes was investigated inin vitro-grownSolanum tuberosumL. cultivars 'Cardinal' and 'Desiree' under salt stress. A 4 x 3 factorial combination of 0, 40, 60, or 80 mM NaCl with 0, 7, or 14 mu M IAA, or 0, 14, or 21 mu M GA(3), were added to Murashige and Skoog (MS) basal medium, followed by inoculation of nodal explants or callus cultures. The data for root and shoot number and length, number of nodes and leaves, fresh weight of plants, increase or decrease in fresh weight of callus cultures, total soluble protein, and superoxide dismutase (SOD) and peroxidase (POD) activities were recorded after 30 d. The growth of both callus cultures and nodal explants subjected to NaCl stress was substantially reduced compared with the control. Both IAA and GA(3)successfully alleviated the harmful effects of salt stress on all of the growth parameters studied. Salt stress resulted in decreased protein content, which increased when the media also contained phytohormones. The activities of SOD and POD were increased with either IAA or GA(3)under NaCl stress. Therefore, the exogenous application of both IAA and GA(3)not only played a positive role in terms ofin vitropotato growth but also significantly affected the biochemical parameters tested.