PHYSIOLOGICAL SIGNIFICANCE OF PROLINE AND GLYCINEBETAINE - MAINTAINING PHOTOSYNTHESIS DURING NACL STRESS IN WHEAT

Experiments on the physiological significance of accumulation of proli ne and glycinebetaine (GB) in sustaining photosynthesis during salt st ress in wheat in vivo showed that pre-treatment with GB, but not proli ne, alleviated NaCl-induced stomatal and non-stomatal inhibition of ph otosynthesis completely. A permeating and non-dissociating osmoticum, 3-orthomethyl-glucopyranose, also alleviated NaCl-induced perturbation s of photosynthesis, suggesting that GB may work by maintaining chloro plast volume and not by specific effects on photosynthetic processes.