Abstract
Unsaturated fatty acids are a factor affecting membrane functions in plants, and decreased by high salinity. However, relationship between salt tolerance and unsaturated fatty acids in plants has not been fully understood. Here, we examined whether composition of unsaturated fatty acids affects salt tolerance by comparing salt-tolerant pea and salt-sensitive azuki. In -NaCl treatment, ratio of unsaturated fatty acids to saturated fatty acids in shoot was higher in pea (3.5) than in azuki (2.6). This ratio was decreased significantly in azuki (1.2) by 150mM NaCl, while that in pea was decreased slightly (3.0). Sodium content in the shoot of azuki was 2-hold higher than that of pea at 150mM NaCl. The negative correlation between sodium content and ratio of unsaturated fatty acids was similarly observed in the roots. These results suggest that the maintenance of the high proportion of unsaturated fatty acids might induce the high salt tolerance in plants.
