Proline accumulation and nitrate reductase activity in contrasting sorghum lines during mid-season drought stress

Sivaramakrishnan, S and Patell, V Z and Flower, D J and Peacock, J M (1988) Proline accumulation and nitrate reductase activity in contrasting sorghum lines during mid-season drought stress. Physiologia Plantarum, 74 (3). pp. 418-426. ISSN 1399-3054

PDF - Published Version
Download (8MB) | Preview


Six lines of sorghum (Sorghum bicolor L. Moench) with differing drought resistance (IS 22380, ICSV 213, IS 13441 and SPH 263, resistant and IS 12739 and IS 12744, susceptible) were grown under field conditions in the semi-arid tropics and analysed for proline and nitrate reductase activity (NRA; EC during a mid-season drought. The resistant lines accumulated high levels of proline, while the susceptible lines showed no significant proline accumulation. Most of the proline was accumulated after growth of the plants had ceased. In a separate greenhouse experiment, most of the proline was found in the green rather than the fired portions of leaves. The levels returned to that of irrigated controls within 5 days of rewatering. Proline levels increased as leaf water potential and relative water content fell, and there was no apparent difference among the different sorghum lines with change in plant water status. Susceptible lines accumulated less proline than resistant lines as leaf death occurred at higher water potentials. Proline accumulation may, however, contribute to the immediate recovery of plants from drought. Leaf NRA reached high levels at about 35 days after sowing in both the stressed and irrigated plants, after which it declined. The decline in NRA was more pronounced in the stressed than in the irrigated plants and closely followed changes in the growth rate. Upon rewatering, NRA increased several-fold in all the lines and, in contrast to proline accumulation, genotypic differences in NRA were small, both during stress and upon rewatering. The high sensitivity of NRA to mild drought stress was reflected in the rapid decline of activity with small changes in leaf water potential and relative water content. The results are discussed in the light of a possible role for proline during recovery from drought, and the maintenance of NRA during stress and its recovery upon rewatering

Item Type: Article
Uncontrolled Keywords: Drought; growth rate; leaf water potential; nitrate reductase; osmotic adjustment; proline; recovery rate; relative water content; Sorghum bicolor
Subjects: Mandate crops > Sorghum
Depositing User: Ms K Syamalamba
Date Deposited: 26 Sep 2013 08:03
Last Modified: 26 Sep 2013 08:03
Official URL:
Acknowledgement: UNSPECIFIED
View Statistics

Actions (login required)

View Item View Item