Exogenous application of nitric oxide and thiourea regulates on growth and some key physiological processes in maize (Zea mays L.) plants under saline stress.

Abstract

Effect of exogenously applied nitric oxide (NO) and thiourea (TU) in combination was examined in maize plants under saline stress. Seedlings of two maize cultivars (DK 5783 and Apex 836) were grown in pots containing soil salinized with 0 or 100 mM NaCl dissolved in irrigation water. Two levels of NO + TU (3 + 400 or 6 + 500 mg/L) were applied as presowing seed treatment or through leaves of 10-day old maize seedlings. Saline stress significantly suppressed plant fresh biomass, leaf water potential and chlorophyll content, but increased electrolyte leakage in both cultivars. However, these reductions were higher in Apex 836 than those in Dk 5783. Both treatments of combined NO and TU as seed soaking or foliar application were effective in mitigating the adverse effects of saline stress on shoot growth. Seed treatments of both levels of combined NO and TU were more effective in terms of improvement in fresh weights of DK 5783 than foliar treatments. Leaf Na + contents increased whereas those of N and P decreased in maize plants under saline regime. Application of Both modes of treatment of combined NO and TU increased the contents of N and P, but decreased that NO and TU through both modes increased Na+ in salt stressed maize plants. The results of the present study indicate that application of NO and TU compounds in combination alleviated the detrimental effects of salinity and increased resistance to salinity in the maize plants by improving plant growth

Exogenous application of nitric oxide promotes growth and oxidative defense system in highly boron stressed tomato plants bearing fruit

“…Accumulation of essential nutrients within plant cells/tissues is one of the primary requisites for the smooth functioning of plant metabolic processes (Kaya et al, 2014). In the present study, B toxicity lowered down leaf Ca 2+ , N and K + contents in the tomato plants, but foliar-applied NO increased these mineral nutrients in the Bstressed plants.…”

“…Nitric oxide (NO) is an endogenous signaling molecule and its exogenous application seems to be a reasonable strategy to overcome damages from stresses (biotic/abiotic) in different crops (Xie et al, 2008;Yildiztugay et al, 2014;Kaya et al, 2014;Zhang et al, 2014). We observed that foliar-applied NO partly increased fruit yield (quantity/weight) of tomato plants subjected to B toxicity.…”

“…In the present study, B toxicity lowered down leaf Ca 2+ , N and K + contents in the tomato plants, but foliar-applied NO increased these mineral nutrients in the Bstressed plants. A number of studies are available on the role of NO in nutrient accumulation in different plants under stress and non-stress conditions such as maize (Kaya et al, 2014;unpublished data), tomato (Manai et al, 2014), rice (Habib and Ashraf, 2014), and Arachis hypogea . But unfortunately, the role of NO on essential nutrient accumulation under high/low boron containing soils has not been explored yet.…”

Participation of Phytohormones in Adaptation to Salt Stress

“…The protective role of NO treatment was tested in various plants such as tomato, pepper, wheat, barley, rice, maize, soybean, mangrove, or chamomile (Li et al 2008 ;Zheng et al 2010;Fallahi and Khajeh Hosseini 2011 ;Nalousi et al 2012 ;Nasrin et al 2012 ;Simaei et al 2012 ;Kausar et al 2013 ;Ali and Ismail 2014 ;Chen et al 2014 ;Egbichi et al 2014 ;Habib and Ashraf 2014 ;Manai et al 2014 ;Kaya et al 2015 ;Sanam et al 2015 ). In studies conducted by Ali and Ismail ( 2014 ), the application of NO (10 μM of sodium nitroprusside) improved tomato fruit quality in the face of salinity (100 mM NaCl) by enhancing the synthesis of health-promoting compounds ( phenolic compounds, fl avonoids, and alkaloids) in tomato fruits along with signifi cant changes in other quality parameters.…”

“…After the application of phytohormones + SNP, the activities of polyphenol oxidase and phenylalanine ammonia lyase increased, thus reducing the damaging effects of salt stress by enhancing the activity of antioxidative systems. Kaya et al ( 2015 ) tested the effect of NO + thiourea (TU) treatment (two levels of NO + TU: 3 + 400 mg/L and 6 + 500 mg/L) as seed soaking treatment and foliar application in two maize cultivars (Apex 836 and Dk 5783) under salinity conditions (100 mM NaCl). Seed treatment was more effective than foliar application in terms of improvement in fresh weight.…”