Comparative responses of two Trigonella species to salinity and drought stresses in vitro

Effects of salinity and drought on growth, contents of proline, malondialdehyde (MDA), proteinand activity of antioxidative enzymes were studied in two Trigonella species. Seeds andexplants of T. foenum-graecum and T. aphanoneura were grown on Murashige and Skoogmedium (MS) complemented with iso-osmotic concentrations of NaCl (0, 100, 150 mM) andmannitol (0, 180, 275 mM). Growth and relative water content (RWC) of seedlings and callidecreased by increasing of salinity and drought in both species. In contrast to that of calli,proline and protein contents increased in seedlings of both species under both stresses. Theincrease of proline content in seedlings of T. aphanoneura was higher than that of T. foenumgraecumunder NaCl stress. MDA content in seedlings of T. aphanoneura was higher than thatof T. foenum-graecum and increased in both species under salinity. Among antioxidativeenzymes, catalase (CAT) activity increased continuously in seedlings of T. aphanoneuracomparing to that of T. foenum-graecum. Similar increasing trends were obtained regardingCAT activities in calli of both species under both stresses. Increase in activities of SOD, CATand POX was observed in calli of both species under stress. It seems that undifferentiated callirespond more regularly to both stresses. Finally, higher proline content and lower amount ofMDA could be considered as criteria for higher tolerance of T. foenum-graecum seedlingsagainst osmotic stresses.