Protection of plants from ambient ozone by applications of ethylenediurea (EDU): A meta-analytic review

Abstract

A meta-analysis was conducted to quantitatively assess the effects of ethylenediurea (EDU) on ozone (O 3 ) injury, growth, physiology and productivity of plants grown in ambient air conditions. Results indicated that EDU significantly reduced O 3 -caused visible injury by 76%, and increased photosynthetic rate by 8%, above-ground biomass by 7% and crop yield by 15% in comparison with non-EDU treated plants, suggesting that ozone reduces growth and yield under current ambient conditions. EDU significantly ameliorated the biomass and yield of crops and grasses, but had no significant effect on tree growth with an exception of stem diameter. EDU applied as a soil drench at a concentration of 200e400 mg/L has the highest positive effect on crops grown in the field. Long-term research on full-grown tree species is needed. In conclusion, EDU is a powerful tool for assessing effects of ambient [O 3 ] on vegetation.

Assessing the effects of ambient ozone in China on snap bean genotypes by using ethylenediurea (EDU)

“…S156. Biomass increases by EDU have been observed previously in snap bean (Brunschon-Harti et al, 1995), as well as in other crops (Feng et al, 2010a). Increases in pod and seed yield in Eþ plants were about 50% in sensitive genotypes S156 and DDW, but not significant in tolerant ones.…”

“…Notably, plants selected for the present experiment are among the most sensitive crops (Feng and Kobayashi, 2009), and they have been exposed to very high ambient ozone concentration, therefore deleterious effects of ozone on E-plants are more evident than in other studies. On the other hand, as observed in the present study in sensitive genotypes, a common response of plants to EDU is a relative increase in chlorophyll and carotenoids (Agrawal et al, 2005;Feng et al, 2010a;Singh and Agrawal, 2011). Ozone induces ROS production which damages chloroplast membranes and associated molecules such as chlorophylls.…”

“…Feng et al, 2008). However, contrasting results have reported: while in a meta-analysis of EDU effects on plants it was concluded that EDU did not modify the g s of plants (Feng et al, 2010a), individual experiments show both increasing and decreasing g s in EDU-treated plants and even transitory increases but final decreases (Manning et al, 2011). Protection of photosynthesis by EDU in sensitive genotypes is also a conclusion of this experiment as A sat , Vc max , J max , and fluorescence parameters (F 0 v =F 0 m , ETR and qP) in the light increased.…”

“…The results of Feng et al (2010a) and Manning et al (2011) showed that 450 ppm EDU effectively protect different plants species from ozone. Therefore, half of the plants were treated with 450 ppm EDU (Eþ from now on) and half with water (E-from now on) in current study.…”

“…Ethylenediurea (N-[2-(2-oxo-1-imidazolidinyl)ethyl]-N-phenyl urea), abbreviated as EDU, has been used extensively to assess the ozone-induced impacts on many crops, e.g wheat, potato, bean, and tomato (Feng et al, 2010a). The application of EDU as a 'control' to ambient ozone is useful to determine ambient ozone effects in fieldgrown plants, particularly in many remote and developing regions where electricity and funding are limited (Blum et al, 1998;Hassan et al, 1995;Manning et al, 2011;Tiwari and Agrawal, 2010).…”