Promotive effect of exogenously applied thiourea on key physiological parametersand oxidative defense mechanism in salt-stressed Zea mays L. plants

Authors : Cengiz KAYA, Muhammad ASHRAF, Osman SÖNMEZ

Pages : 786-795

View : 21 | Download : 7

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A greenhouse experiment was conducted to examine the alleviating role of thiourea insert ignore into journalissuearticles values(TU); on antioxidants and some vital physiological attributes in salt-stressed plants of two maize cultivars. The maize cv. DK 5783 performed better than cv. Apex 836 in an initial experiment. Of the six TU levels used in the initial experiment, 400 and 500 mg L-1 were chosen for subsequent studies. The two cultivars were subjected to saline stress insert ignore into journalissuearticles values(100 mM NaCl); and two levels of TU were applied presowing or as foliage spray. Salt stress suppressed total biomass, maximum fluorescence yield insert ignore into journalissuearticles values(Fv/Fm);, chlorophyll, and leaf water potential insert ignore into journalissuearticles values($\Psi$w);, but it increased proline, hydrogen peroxide insert ignore into journalissuearticles values(H2O2);, malondialdehyde insert ignore into journalissuearticles values(MDA);, leaf osmolality insert ignore into journalissuearticles values(LO);, membrane permeability insert ignore into journalissuearticles values(MP);, and antioxidant enzymes. Exogenous TU application resulted in considerable increases in the dry weight of salt sensitive and tolerant cultivars insert ignore into journalissuearticles values(38% and 35%, respectively);. TU partially improved the salt tolerance of maize plants; it reduced Na+ but increased N, K+, Ca2+, and P in the maize plants under saline regimes. TU regulated the growth of maize plants under stress conditions by reducing MP, MDA, and H2O2 levels, and altering activities of antioxidant enzymes as well as increasing photosynthetic pigments under a saline regime.
Keywords : Maize, thiourea, salt tolerance, oxidative stress, leaf water potential