Potential of Seed Halopriming in Mitigating NaCl-induced Adversities on Nitrogen Metabolism in Legume Crops

Abstract

Background: Salinity is a major threat that impairs legume growth and development worldwide. Therefore, present study was aimed to determine the potential of seed halopriming in relieving NaCl-induced disturbances on nitrogen metabolism of seedlings of six legume crops viz., Lens culinaris, Cajanus cajan, Cicer arietinum, Lathyrus sativus, Vigna radiata and Vigna mungo that were detected to have differential sensitivity to NaCl. Methods: Nonprimed and haloprimed seeds were grown hydroponically under varying NaCl doses for three weeks. Harvested samples were utilised to characterize the toxic effects of NaCl on nitrogen metabolism of nonprimed and haloprimed seedlings. Results: Nonprimed seedlings exhibited reduced nitrate uptake by virtue of which other assimilatory processes of nitrogen fixation were adversely affected. Haloprimed seedlings experienced lesser toxicity under NaCl stress due to elevated activities of nitrate assimilatory enzymes on account of improved nitrate uptake from solution. Lesser ammonium accumulation and lower glutamate dehydrogenase activity implied lesser cytotoxicity in primed seedlings. Based on the trends obtained from tested parameters, nitrogen metabolism was maximally affected in Lens and Cajanus followed by Cicer and Lathyrus. Vigna radiata and Vigna mungo were least affected and therefore may be suggested for cultivation in saline prone agricultural fields after seed halopriming.