Comparison of Adaptability to Flash Flood between Rice Cultivars Differing in Flash Flood Tolerance uri icon

abstract

  • The mechanism of flash flood tolerance was investigated by using a flash flood-intolerant rice cultivar (Oryza sativa), IR42 and a tolerant one, FR13A. The photosynthetic rate of the rice seedlings from both types of cultivars decreased during submergence, whereas the photosynthetic rate of FR13A remained higher than that of IR42. The decrease in photosynthesis in IR42 was partially due to a higher inhibition of the activities of ribulose-1,5-bisphosphate carboxylase, fructose-1,6-bisphosphatase, and glyceraldehyde-3-phosphate dehydrogenase, than in FR13A. After submergence receded (hereafter referred as "desubmergence"), both types of submerged rice cultivars experienced oxidative damage. However the oxidation of the lipids and proteins in FR13A was maintained at a lower level than that in IR42 after desubmergence. On the other hand, the superoxide dismutase activity in FR13A increased more than that in IR42 after desubmergence. Moreover, the content of total ascorbate (reduced and oxidized ascorbates), a main antioxidant increased in FR13A, while in IR42 the content remained low after desubmergence. It is assumed that the photosynthetic activity during submergence may be related to flash flood tolerance. Moreover, flash flood tolerance requires a rapid stimulation of antioxidant systems after desubmergence.

publication date

  • 2002
  • 2002