CHANGES IN LEAF WATER POTENTIAL, OSMOTIC ADJUSTMENT, AND PROLINE METABOLISM IN MULBERRY DURING WATER STRESS

The influence of water stress on amino acid content and proline metabolism was studied in 3-month-old mulberry plants at four levels of water stress. Leaf water potential and osmotic potential were significantly decreased in all stress treatments. Though leaf area and relative water content decreased, significantly, a marked decrease was observed only in severe stress treatment. Accumulation of total amino acids and proline was observed both in roots and leaves in stress treatments, with amino acid accumulation greater in leaves than in roots. In contrast, proline accumulation was greater in roots than in leaves. Activities of proline dehydrogenase and proline oxidase were inhibited under stress conditions. Inhibition of proline oxidase was greater in roots than in leaves.