Plants differ marlredly in their tolerance to drought.
Several aspects of metabolism such as inhibition of
protein synthesis and changes in amino acid metabolism
have been shown to be affected by water deficit [l].
Although the concentrations of some amino acids decline
during water stress, there is an overall increase in the
concentration of soluble nitrogenous compounds [2].
Water stress leads to a rapid and extensive accumulation
of proline which varies considerably between different
genotypes. A decrease in nitrate reductase in corn and
barley [l], and an increase in ribonuclease activity [4]
with moisture stress has been observed. An earlier
study [5] showed differences in peroxidase isoenzymes
in rice varieties differing in their tolerance to drought.
However, the information on changes in various enzymes
in genotypes differing in their tolerance to drought is
lacking. Therefore in the present study the effect of
moisture stress on peroxidase, ribonuclease, nitrate
reductase, protease and proline accumulation in TKM-1
a drought tolerant and Improved Sabarmati (I.S.) a
drought susceptible rice variety has been studied.