Abstract:
A comprative study evaluation of response of salt stress on different of oxidative and changes in the profile of fatty acids in two varities of rice (Oryza sativa) has been portrayed in our work. 'Jaya' variety of rice exhibited greater amount of membrane stability (MSI), hydrogen peroxide (H sub(2) O sub(2)) and hydroxyl radicale (OH.) and protein carbonyl production compared to those of 'Korgut' rice variety under salinity stress. GC-MS analysis confirms that the composition of fatty acids in leaves of both varieties was established primarily by 16:0 and 18:0 (primary saturated fatty acids) and 18:1 omega -9, 18:2 omega -6 and 18:3 omega -3 (primary unsaturated fatty acids). The 'Jaya' variety showed higher levels of saturated fatty acids in membrane lipids than the 'Korgut' variety. In contrast, the 'Korgut' variety displayed an enhanced level of unsaturated fatty acid (linolenic and oleic acids), which is one of the characteristics responsible for making 'Korgut' more tolerant than the 'Jaya' variety. At the same time, 'Korgut' showed a much higher level of total fatty acid content than that of the 'Jaya' variety. In 'Jaya', the alpha-Linolenic acid (18:3 omega 3) has been observed only in control, and was absent in treated ones, inferring that salinity alters the nutritional value of the rice seedling. However, 18:3 omega 3 was detected in the 'Korgut' variety at all concentrations of NaCl, indicating the probability of its role in maintaining membrane fluidity and a defense mechanism against salinity stress. These pieces of evidence indicate that these fatty acids are potential molecular markers, useful for genetic programs as well as for future basic studies on salt tolerant behavior of rice.
