Chin J Plant Ecol ›› 2007, Vol. 31 ›› Issue (5): 946-951.DOI: 10.17521/cjpe.2007.0120

• Research Articles • Previous Articles     Next Articles


WANG Yi-Bo1,2, FENG Hu-Yuan2, QU Ying2, CHENG Jia-Qiang2, $\boxed{\hbox{WANG Xun-Ling}}$ 2, AN Li-Zhe2,3,*()   

  1. 1Department of Biology, Tianshui Normal College, Tianshui, Gansu 741000, China
    2School of Life Sciences, Lanzhou University, Lanzhou 730000, China
    3Cold and Arid Region Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2005-12-15 Accepted:2007-01-11 Online:2007-12-15 Published:2007-09-30
  • Contact: AN Li-Zhe


Aims Ethylene accumulation and oxidative stress are two common responses of plants to environmental stresses; however, little is known about their relationships. Our objective was to investigate the role of reactive oxygen species (ROS) in ethylene synthesis induced by UV-B radiation (280-320 nm) in leaves of maize (Zea mays).

Methods Lamps were suspended above and perpendicular to the plastic trays and filtered with 0.13-mm thick cellulose diacetate (transmission down to 290 nm) for UV-B irradiance. The desired UV-B irradiation was obtained by changing the distance between the lamps and the plastic trays. The levels of UV-B irradiation were 4.8 kJ·m-2·d-1.

Important findings UV-B radiation led to the generation of ROS and ethylene. The accumulation of ethylene induced by UV-B was not only inhibited by the scavengers of ROS, but also by aminoxyacetic acid (AOA) and 2-aminoethoxyvinlglycine (AVG), which are specific inhibitors of ethylene synthesis. The inhibition effect of ROS scavengers on UV-B-induced ethylene production was reversed by $\text{O}_{2}^{{\bar{.}}}$ donors. Results indicated that the increase in ethylene production may not be the cause of the increase in ROS production under UV-B stress. In contrast, the increase of ROS led to the accumulation of ethylene. Results suggested that ROS are involved in UV-B stress-induced ethylene accumulation. The accumulation of UV-B-induced ethylene was not affected by DPI, an inhibitor of NADPH oxidase and CAT, a specific scavenger of H2O2. Results suggested that the effect of H2O2 on UV-B-induced ethylene production in leaves of maize seedlings can be excluded, $\text{O}_{2}^{{\bar{.}}}$ plays an important role in UV-B-induced ethylene synthesis in leaves of maize seedlings and $\text{O}_{2}^{{\bar{.}}}$ serves as a potential mediator of ethylene production that the plant can sense the UV-B stress. The related ROS are not from plasma membrane NADPH oxidase. The source of ROS contributing to ethylene accumulation under UV-B stress is unknown.

Key words: reactive oxygen species (ROS), ultraviolet-B radiation (UV-B), ethylene production, maize