105

Role of Hydropriming and Magneto-Priming in Developing Stress Tolerance

decreased the SMF-induced seed germination, seedling growth, activities of

𝛼-amylase, protease, and NR, ROS, and NO content in roots of soybean

seedlings. Although the percentage of reduction in NO and NR was higher

with ST treatment compared to LNAME in seedlings of SMF-primed seeds,

the NO donor (sodium nitroprusside (SNP)) promoted all the parameters in

saline and non-saline condition.

4.2.2 DROUGHT STRESS

Water stress can also potentially affect seed germination and early seed­

ling growth (Ahmad et al., 2009). In maize, magneto-priming helped the

seedlings to withstand moisture stress due to improved soil-water relations

(Anand et al., 2012). Javed et al. (2011) found that SMF (100 and 150

mT for 10 min) was effective in alleviating the drought-induced adverse

effects on maize growth by improving photosynthetic efficiency through

photochemical and non-photochemical quenching. Selim & El-Nady (2011)

reported that magnetic field treated tomato seeds resulted in stimulation

of plant growth, cambium differentiation activity, thickness of mesophyll

tissue, water uptake, proline concentration and photosynthetic pigments in

response to drought stress. Improvement in chlorophyll and carotenoids

and decreased SOD, POX, APX, and CAT activities under drought stress

was also observed by Sen & Alikamanoglu (2014) in plants from SMF (2.9

mT–4.7 mT) treated wheat seeds. Alvarez et al. (2020) suggested that the

adverse effect of salinity and drought on water absorption in Triticale seeds

can be circumvented by exposing seeds to SMF of 3.71 mT for 10 h. At

the plant level, soybean plants raised from SMF treated seeds and exposed

to water stress at vegetative, flowering, and pod-filling stage showed lesser

reduction in growth, photosynthetic efficiency, and yield (Baghel et al., 2018)

Recently, the beneficial effects of magneto-priming (200 mT for 5 min) on

improvement of drought tolerance in Hyssopus officinalis L. through protec­

tion of cellular membrane integrity, maintenance of photosynthetic pigment

content, alternation of antioxidant enzyme activities were demonstrated by

Mohammadi & Roshandel (2020).

4.2.3 TEMPERATURE STRESS

Among the various abiotic stresses experienced by plants, extreme tempera­

tures have a detrimental effect on the metabolic activities of the plants. Seed