Effect of Putrescine, 4-PU-30, and Abscisic Acid on Maize Plants Grown under Normal, Drought, and Rewatering Conditions

Abstract

The experiments were carried out with maize (Zea mays L.) seedlings, hybrid Kneja 530, grown hydroponically in a growth chamber. Twelve-day-old plants were foliar treated with putrescine, N1-(2-chloro-4-pyridyl)-N2-phenylurea (4-PU-30), and abscisic acid (ABA) at concentrations of 10(-5) m. Twenty-four hours later the plants were subjected to a water deficit program, induced by 15% polyethylene glycol (PEG; molecular weight, 6,000). Three days after drought stress half of the plants were transferred to nutrient solution for the next 3 days. The effects of the water shortage, rewatering, and plant growth regulator (PGR) treatment on the fresh and dry weights, leaf pigment content, proline level, relative water content (RWC), transpiration rate, activities of catalase and guaiacol peroxidase, hydrogen peroxide content, and level of the products of lipid peroxidation were studied. It was established that the application of PGRs alleviated to some extent the plant damage provoked by PEG stress. At the end of the water shortage program the plants treated with these PGRs possessed higher fresh weight than drought-subjected control seedlings. It was found also that putrescine increased the dry weight of plants. Under drought, the RWC and transpiration rate of seedlings declined, but PGR treatment reduced these effects. The accumulation of free proline, malondialdehyde, and hydrogen peroxide was prevented in PGR-treated plants compared with the water stress control. The results provided further information about the influence of putrescine, 4-PU-30, and ABA on maize plants grown under normal, drought, and rewatering conditions. Key Words. Maize-Putrescine-4-PU-30-ABA-Drought

Effects of Coronatine on Growth, Gas Exchange Traits, Chlorophyll Content, Antioxidant Enzymes and Lipid Peroxidation in Maize (Zea mays L.) Seedlings under Simulated Drought Stress

“…The rate of transpiration depends not only on the influence of the stomata, but also on leaf water content and other factors (Ghannoum et al, 2003). Todorov et al (1998) also found a higher rate of transpiration in maize plants treated with ABA under drought condition. Coronatine might have regulated the stomatal conductivity to reduce leaf water consumption under drought stress as reported for ABA (Schroeder et al, 2001;Luan, 2002) and JA or methyl jasmonate (MeJA) (Lan et al, 2004), but this remains to be examined further.…”

Effects of polyamines on cellular innate immune response and the expression of immune-relevant genes in gilthead seabream leucocytes

“…Phagocytosis activity and ROS production in HKLs were concomitantly enhanced during oxidative burst throughout the experiment, which suggests that an enhanced leucocyte microbe-killing capacity is a key factor in increased resistance to disease. These regulations may be attributed to the potential effect of putrescine, which acts as radical scavenger [31]. Bekheta and El-Bassiouny [32] found that foliar application of putrescine in wheat plants decreased peroxidase and polyphenol oxidase, and increased catalase and superoxide dismutase activities.…”

An evaluation of the potentiality of exogenous osmoprotectants mitigating water stress on chickpea

“…All naturally polyamines including spermidine, spermine, codavarine and putrescine strongly inhibited opening of stomata (Liu-Kun et al, 2000). Some of the results are well documented as on chickpea under salinity (Dhingra et al, 1997), maize under drought (Todorov-D et al, 1998) and on groundnut seedling (Vakharia et al, 2003), which suggest the possibility of foliar application of putrescine to mitigate the effect of water stress. In legumes, moisture stress has drastic effects on nitrogen fixation besides plant growth (Sinclair et al, 1987 andSerraj et al, 1999).…”