Drought and osmotic stresses are major threats to agricultural
crops as they affect plants during their life cycle. The seeds are
more susceptible to these stresses during germination and establishment
of seedlings. To cope with these abiotic stresses, various seed priming
techniques have broadly been used. The present study aimed to assess
seed priming techniques under osmotic stress. Osmo-priming with chitosan
(1 and 2%), hydro-priming with distilled water, and thermo-priming
at 4 °C were used on the physiology and agronomy ofZea maysL. under polyethylene glycol (PEG-4000)-induced
osmotic stress (−0.2 and −0.4 MPa). The vegetative response,
osmolyte content, and antioxidant enzymes of two varieties (Pearl
and Sargodha 2002 White) were studied under induced osmotic stress.
The results showed that seed germination and seedling growth were
inhibited under osmotic stress and germination percentage, and the
seed vigor index was enhanced in both varieties ofZ. maysL. with chitosan osmo-priming. Osmo-priming
with chitosan and hydro-priming with distilled water modulated the
level of photosynthetic pigments and proline, which were reduced under
induced osmotic stress; moreover, the activities of antioxidant enzymes
were improved significantly. In conclusion, osmotic stress adversely
affects the growth and physiological attributes; on the contrary,
seed priming ameliorated the stress tolerance resistance ofZ. maysL. cultivars to PEG-induced osmotic stress
by activating the natural antioxidation enzymatic system and accumulating
osmolytes.