No abstract

Plant water status and cellular osmotic adjustments play a key role in the salt tolerance of plants. An experiment was conducted to assess the influence of foliarapplied ascorbic acid (AsA) on the plant water relations, cellular osmotic adjustments, uptake, and accumulation of different ions in the two high yielding maize cultivars (Agaiti-2002 and EV-1098) at early growth stage under salt stress (120 mM NaCl). Salt stress altered growth, water relation attributes, osmolytes accumulation, and decreased the uptake of K ? , Ca 2? , P, and N, while increased the uptake and accumulation of Na ? in different plant parts (leaf, stem, and root). Exogenous AsA increased the accumulation of AsA in different plant parts, particularly in leaves and roots. Moreover, AsA application resulted in the accumulation of proline and glycinebetaine (GB) in the roots and leaves of both maize cultivars when under salt stress. Foliar application of AsA also increased the uptake of minerals such as K ? , Ca 2? , P, and N and decreased the uptake and accumulation of Na ? in different plant parts. Taken together, the AsA-induced enhanced accumulation of osmolytes (GB and proline) and AsA increased the K ? / Na ? ratio, and more accumulation of beneficial nutrients in the roots and leaves enhanced water uptake from soil and reduced the negative effects of Na ? in the salt-stressed maize plants. The results suggested that foliar-applied AsA either accelerated the tissue-specific translocation of AsA or altered the de novo synthesis of AsA to mitigate the adverse effects of salinity in maize plants.

Water shortage is one of the major environmental constraints that hamper the crop productivity worldwide. The present study was aimed to examine the drought tolerance potential of seven cultivars/lines of Vigna mungo L. depending upon their germination behavior, seedling growth, antioxidative defense mechanism, and nutrient acquisition. An experiment was conducted in the growth chamber using petri-plates and laid out in a completely randomized design (CRD). Hoagland's nutrient solution supplemented with 12 % PEG-8000 (drought treatment) or without PEG-800 (control) was used. Drought stress significantly altered the germination attributes as well as biomass production of all the studied cultivars/lines. Least adversative effects of drought stress were recorded in lines M-01001-1 and M-6036-21, respectively. The studied cultivars/lines exhibited differential response for various biochemical attributes under drought stress. The maximum increase in MDA and SOD activities and protein content was recorded in line M-6036-21, while the maximum AsA was recorded in line M-01001-1. Drought stress resulted in a significant reduction of plant N, P, K, Ca, and Mg contents, while the plant iron (Fe) contents remained unaffected. Results revealed that cultivars/lines M-01001-1 and M-6036-21 exhibited enhanced performance in terms of nutrient acquisition when stressed by drought. Based upon seed germination behavior, plant biomass production, biochemical attributes and mineral elements, the cultivars/lines M-01001-1 and M-6036-21 were identified as drought tolerant, while M-97 and Arroj-II were identified as drought sensitive.