biologia plantarum

Biologia plantarum 56:635-640, 2012 | DOI: 10.1007/s10535-012-0115-1

Modified alternative oxidase expression results in different reactive oxygen species content in Arabidopsis cell culture but not in whole plants

V. I. Tarasenko^1,*, E. Y. Garnik¹, V. N. Shmakov¹, Y. M. Konstantinov¹

¹ Siberian Institute of Plant Physiology and Biochemistry, Siberian Division of the Russian Academy of Sciences, Irkutsk, Russia

Alternative oxidase (AOX) transfers electrons from ubiquinone to oxygen in the respiratory chain of plant mitochondria. It is widely accepted that AOX functions as a mechanism decreasing the formation of reactive oxygen species (ROS) produced during respiratory electron transport. However, there are no experimental data to provide unambiguous proof of this hypothesis. We have studied growth characteristics, ROS content, and stress sensitivity in Arabidopsis transgenic lines with reduced or increased levels of AOX. We demonstrated that AOX-deficient plants grown in soil had an extended reproductive phase. Changes in AOX activity did not affect ROS content or stress sensitivity in the whole plants. However in the suspension culture, cells overexpressing AOX had significantly lower ROS content, whereas the AOX-deficient cells had higher ROS contents compared to the wild-type (WT) cells. Prooxidant treatment led to the increase in ROS content and to the reduction of viability more in the cells overexpressing AOX than in WT and AOX-deficient cells. Thus, we demonstrated that differences in the metabolism of whole plants and cultured cells might affect AOX functioning.

Keywords: antimycin A; hydrogen peroxide; menadione; oxidative stress; superoxide; suspension culture

Subjects: alternative oxidase; in vitro culture; cell suspension; hydrogen peroxide; superoxide radical; transgenic plants; Northern blot; menadione; respiration; reactive oxygen species

Species: Arabidopsis thaliana

Received: May 30, 2011; Accepted: November 15, 2011; Published: December 1, 2012Show citation