Water Stress Induced Alterations in Chloroplast Activity and Nitrogen Metabolism During Development of Clusterbean Cotyledons in Low Light Intensity

Abstract

Water stress and variation in light intensity play a critical role in determining chloroplast structure and photosynthetic properties of the leaves (1,2). Since nitrogen metabolism is linked to functional plastids in green tissues (3.4), the stress induced changes in development of the organelle might affect nitrogen metabolism in the leaves. Although some reports are available on the effects of low light intensity or water stress alone on chloroplast development and nitrate reductase (NR) activity separately, apparently less information is available on the modulation of both the processes by interacting water and light stress factors. In the present work, the alterations in structure and function of the chloroplasts, nitrate uptake capacity and NR activity are examined in the developing cotyledons of clusterbean under low light stress alone or in combination with water stress.