Proline is involved in water stress responses of Lotus corniculatus nitrogen fixing and nitrate fed plants

Water stress induced proline accumulation in Lotus corniculatus regardless of the nitrogen source provided to plants, although this accumulation was h igher in nitrogen fixing plants. Enzymes related to synthesis and oxidation of proline were analysed. Fd-GOGAT activity and Fd-GOGAT protein content i ncreased in response to water stress in contrast to PDH activity, which dec reased under such condition. However, rehydration for 6 h induced an increm ent in PDH activity. The differential effect of water deficit on enzymes in volved in the proline pathway in L. corniculatus plants growing under diffe rent nitrogen regimes is discussed. The possible role of nitrate as an osmo protectant in the place of proline is also considered.