Mitigation of adverse effects of salt stress on germination, growth, photosynthetic efficiency and yield in maize (Zea mays L.) through magnetopriming

Abstract

The efficiency of magnetopriming was evaluated for mitigation of the detrimental effects of salt stress on maize germination, growth, photosynthesis, and yield of maize plants. Maize seeds were pretreated with 200 mT of static magnetic field (SMF) for 1 h to assess the impact of SMF on the germination, seedling vigor, growth of plant, photosynthetic performance, ROS content, and yield under salt stress. The seedling characteristics of maize were negatively influenced by salt stress. However, SMF-pretreated maize seeds showed relatively higher germination percentage and germination stress tolerance index as compared to untreated seeds in saline and nonsaline conditions. The detrimental effect of NaCl induced salt stress was also observed on growth, yield, and different physiological characteristic of maize plants.The results showed that SMF-pretreated seeds enhanced seedling vigor, growth parameters such as plant height, leaf area, and biomass accumulation at different concentrations of NaCl (0, 25, 50, 75, and 100 mM) as compared to untreated seeds. Photosynthetic pigments, quantum yield of PSII photochemistry (Fv/Fm), phenomenological fluxes such as electron transport per leaf CS (ETo/CSm) and density of reaction centers (RC/CSm), the performance index (PI) were high in the leaves of plants that emerged from SMF-pretreated seeds as compared to untreated seeds. This stimulatory effect of SMF treatment of seeds was also revealed in the rate of photosynthesis and stomatal conductance, which results in improved yield of maize plants under saline conditions. The leaves from plants of SMF-treated seeds showed decreased hydrogen peroxide (H 2 O 2 ) when compared with untreated seeds in both conditions. SMF ameliorates the adverse effect of salt stress in maize plants, by reducing H 2 O 2 and increasing growth, photosynthetic performance, and yield under salt stress. For improvement of salt tolerance, magnetopriming with SMF of 200 mT for 1 h to dry seeds of maize can be efficiently used as a presowing treatment.

Involvement of nitrate reductase‐dependent nitric oxide production in magnetopriming‐induced salt tolerance in soybean

“…In contrast, SMF‐priming significantly increased the early growth characteristics of the seedlings along with an increase in enzyme activities (α‐amylase, protease and NR), ROS and NO content in the absence and presence of salt stress. This effect of magnetic biostimulation of seed germination using SMF has been reported in several plant species in non‐stress and abiotic stress conditions (Kataria et al , Baghel et al , Kataria et al , ). SMF pre‐treatment increase the germination and vigor of seedlings by affecting the biochemical processes like free radical formation and by raising the enzymes activity related to seed germination (Kataria et al , Anand et al , Baghel et al ).…”

“…After 5 d (120 h of seed imbibition), the number of germinated seeds compared to total number of the seeds was counted to assess the percentage of germination. The stress tolerance index for germination was calculated as suggested by Baghel et al () for non‐primed and SMF‐primed seeds: stress tolerance index of germination (GSTI) = (PI of seeds in salt stress / PI of seeds of controls) × 100, where PI is the promptness index calculates as follows PI = nd 1 (1.00) + nd 2 (0.75) + nd 3 (0.50) + nd 4 (0.25), nd is the number of seeds germinated on the day of observation. And nd 1 , nd 2 , nd 3 and nd 4 are then number of seeds germinated, respectively, on the first, second, third and fourth day.…”

“…Magnetopriming with static magnetic field (SMF) increases seed germination (Kataria et al , Shine et al , Kataria and Jain ), speed of germination (Anand et al ), plant development (Kataria et al ,b, ), length and mass of the root and shoot (Vashisth and Nagarajan , Shine et al ), vigor indices (Kataria et al , Shine et al ), photosynthetic performance (Shine et al , Baghel et al ) and ultimately yield of plants (Kataria and Jain , Kataria et al ). During germination, seeds priming with SMF enhanced the content of reactive oxygen species (ROS) and enzyme activities such as α‐amylase, protease and nitrate reductase in wheat, sunflower, soybean and maize (Bhatnagar and Deb , Kataria et al , Baghel et al , Anand et al ). ROS like O 2 •− and H 2 O 2 may take part as a key signaling molecules in accomplishment of seed germination or release of seed dormancy (Sarath et al , Anand et al ).…”

Magnetic Field (MF) Applications in Plants: An Overview

“…They also observed, in seedlings derived from treated seeds, an increase in stem length, stem diameter, leaf area, and fresh and dry weight, even under saline conditions. Several studies have shown that SMF can increase the seed germination and seedling vigor under salt and heavy metal stress in chickpea, soybean, barley, mung bean, and maize [ 20 , 21 , 47 , 84 , 85 ].…”

Effects of Phosphorus Fertilization on Hybrid Varieties of mungbean [Vigna radiata (L.) Wilczek] in a Salinity Prone Area of the Subtropics

“…Salinity is another very important yield limiting factor in crop lands, principally in arid and semiarid regions of the world (Baghel et al, 2019). Salinity stress not only influences vegetative growth, but also affects reproductive structures and translocation of C and N to developing seeds and fruits.…”