The effect of water stress on nitrogen metabolism of horsegram Dolichos biflorus L.

Horsegram plants were raised in terule soil in earthen pots and subjected to various durations of water stress (7, 14 and 21 days). Total nitrogen contents were reduced in water-stressed plants but differently in different plant parts. Nitrate content and nitrate reductase activity decreased with stress. This species possesses a good capacity for accumulation of free proline under water stress. Analysis of amino acid composition also revealed marked changes in the levels of various amino acids in water-stressed plants. Accumulation of γ-aminobutyric acid in water-stressed plants was observed.