The present study examined the effects of 24-h and 72-h NaCl treatment on germination, germination velocity, and the associated biochemical changes in protein and RNA contents of 2 seed morphs, and compared these effects after transfer into distilled water or 10 mM thiourea solution. | Turk J Biol 30 (2006) 185-193 © TÜB‹TAK Biochemical Responses of Dimorphic Seeds of Arthrocnemum indicum Willd. during Germination, Inhibition, and Alleviation under Saline and Non-Saline Conditions Zamin Shaheed SIDDIQUI Stress Physiology & Environmental Pollution Laboratory, Department of Botany, University of Karachi, Karachi-75270 - PAK‹STAN Received: Abstract: Dimorphic seeds of Arthrocnemum indicum (a halophytic shrub) exhibit diverse germination responses following salinity treatment and subsequent exposure to growth regulators by adjusting their physiological and biochemical processes. The present study examined the effects of 24-h and 72-h NaCl treatment on germination, germination velocity, and the associated biochemical changes in protein and RNA contents of 2 seed morphs, and compared these effects after transfer into distilled water or 10 mM thiourea solution. Treatment for 24 and 72 h in NaCl solution induced a significant reduction in the rate of germination and final percent germination of both seed morphs. No germination took place in brown winter seeds in 300 and 400 mM NaCl treatment. In a separate experiment, seeds previously treated with NaCl for 24 and 72 h were transferred to distilled water or thiourea, and final germination was recorded. Germination velocities were higher following transfer into thiourea than into distilled water for black summer seeds, but not for brown winter seeds. The damage caused by salinity to total protein and RNA contents were not completely alleviated by the use of thiourea or distilled water, but showed only a limited tendency to recover from salinity stress. The seeds imbibed in different salt concentrations for different time periods exhibited different capacities to recover after their transfer into distilled water or thiourea. The inhibitory effects of NaCl on germination were more pronounced on brown seeds than on black seeds. Key Words: Distilled water, DNA, germination, protein, RNA, salt, .
