Seed priming with zinc oxide nanoparticles improves growth, osmolyte accumulation, antioxidant defence and yield quality of water-stressed mung bean plants

Abstract

The mung bean [Vigna radiata (L.) Wilczek] grown in arid lands experiences yield losses due to the non-availability of water at pod filling and flowering stages which may be moderated by seed priming use of nanomaterials. The present study was based on the hypothesis that seed priming with zinc oxide nanoparticles (ZnO_NPs) can moderate the adverse effects of aridity on mung bean plants by improving crop performance in terms of growth, antioxidant defence, and yield. The hypothesis was tested in field trials in a split plot factorial design. The seed priming with 75 ppm ZnO_NPs improved the growth of water-stressed mung bean plants in terms of shoot length, root length, number of leaves, number of vegetative branches per plant, and number of reproductive branches per plant by 32%, 24%, 43%, 39%, and 30% respectively compared to control. Furthermore, the seed priming with 75 ppm ZnO_NPs caused the accumulation of osmolytes such as proline, total soluble sugars, and total soluble protein by 18%, 14%, and 81% respectively. The levels of malondialdehyde and hydrogen peroxide were depressed significantly and antioxidant defence functioning was improved by seed priming treatments with ZnO_NPs. The yield profile of water-stressed plants improved significantly in terms of pod length, number of grains per pod, number of pods per plant, seed yield, biological yield, and harvest index by 37%, 50%, 39%, 16%, 9%, and 6% respectively. The yield and production of mung bean plants can be improved through seed priming with ZnO_NPs when grown in arid lands.