Interactive effects of ozone and drought stress on plants: A review

Abstract

Ground-level ozone (O 3) and drought are two key factors limiting plant growth. O 3 can enter into the plant tissue through the stomata, then causing the formation of reactive oxygen species (ROS) which inspires programmed cell death. Drought usually induces the accumulation of ROS due to damage to antioxidant systems of plants. The effects of two kinds of stress on plants are similar due to the accumulation of ROS, resulting in reduced photosynthesis rate and physiological metabolism, eventually decreased plant growth and biomass. Nevertheless, O 3 and drought interacts synergistically to accumulate detrimental effects or antagonistically to reduce harmful effects. Actually, it is complex interactive process between O 3 and drought. On the one hand, O 3 triggers stomatal sluggishness or even dysfunction, which exacerbates water transpiration of leaves, water loss from plants and further O 3 phytotoxicity. On the other hand, drought induces stomatal closure, and thus protecting plants against the O 3 influx and evaporation of water. However, prolonged drought could limit the uptake of CO 2 and thus result in reduced plant growth. The response of plants to both O 3 and drought not only depends on the occurring sequence and duration of any factor but also rely on the difference in physiological metabolism of the plant itself. The interactive effects of O 3 and drought on stomatal characteristics, photosynthetic carbon mechanism, antioxidant response and growth development are reviewed in this paper and the aspects to be further studied are also suggested.

The Effects of Dual Ozone and Drought Stresses on the Photosynthetic Properties of Acer rubrum and A. pictum

“…Under SD conditions, the Pn of A. rubrum and A. pictum increased under O 3 stress, and Gs increased slightly or remained stable, indicating that drought can alleviate the damage caused by O 3 to the Pn of plant leaves, which is consistent with previous studies [22]. Drought induces the closure of stomata, limits the O 3 dose entering the leaves, and plays an antagonistic role in protecting plants, thus stimulating the adaptation and protection mechanisms of plants against adversity and reducing the damage caused by O 3 to leaves [26].…”

“…However, Hao et al [24] and Ye et al [25] found that the seedlings of Alstonia scholaris and Syzygium hainanense were more affected by the dual stresses of O 3 and drought than by their individual stress effects and that S. hainanense seedlings showed stronger anti-O 3 and drought resistant responses than A. scholaris. Another study has shown that plants are unaffected by dual stresses [26], suggesting a lack of consensus regarding the effects of these dual stresses on different plants.…”

Response of Fluorescence and Chlorophyll Physiological Characteristics of Typical Urban Trees to Ozone Stress

“…In addition to changing the stomatal properties of trees, ozone stress also restricts the non-stomatal factors of leaves, which is mainly reflected in the decrease in chloroplast content caused by cell membrane damage [5], thus affecting the growth of trees. Gao et al [6] pointed out that with the increase in ozone concentration, the chlorophyll fluorescence index and chlorophyll content decreased. In addition, ozone impeded photoelectron transfer, resulting in a significant decline in its rate.…”