|PLATISA, JELENA - UNIV OF BELGRADE SERBIA
|VELJOVIC-JOVANOVIC, SONJA - UNIV OF BELGRADE SERBIA
|KUKAVICA, BILJANA - UNIV OF BELGRADE SERBIA
|VINTERHALTER, BRANKA - INST OF BIOLOGICAL SERBIA
|NINKOVIC, SLAVICA - INST OF BIOLOGICAL SERBIA
Submitted to: Journal of Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/2007
Publication Date: 9/21/2007
Citation: Platisa, J., Veljovic-Jovanovic, S., Kukavica, B., Vinterhalter, B., Smigocki, A.C., Ninkovic, S. 2007. Induction of peroxidases and superoxide dismutases in transformed embryogenic calli of alfalfa (Medicago sativa L.). Journal of Plant Physiology. http://dx.doi.org/10.1016/.jplph.2007.07.021
Interpretive Summary: Modifying crop plants with genetic techniques can lead to safer and more profitable farming. However, genetic modification of plants often generates unintended effects that are unrelated to target traits. The stress created by the genetic modification process is speculated to disturb the balance of protective chemicals (called antioxidants) inside the cells that keep them from being damaged. We determined that alfalfa tissues that were genetically modified to increase insect resistance had elevated levels of compounds (enzymes) that are involved in the synthesis of antioxidants. Our results suggest that the elevated antioxidant enzyme levels may prevent genetically modified cells from growing into whole plants thus precluding seed production for further studies and eventual distribution to farmers. This information will be of interest to scientists studying the effects of newly incorporated traits on growth and development of genetically modified plants.
Technical Abstract: Activities of peroxidase (POD) and superoxide dismutase (SOD) enzymes were analyzed in non-regenerative transformed embryogenic lines of alfalfa (Medicago sativa L.) carrying wound-inducible oryzacystatin I (OC-I), wound-inducible oryzacystatin I antisense (OC-Ias) or hygromycin phosphotransferase (hpt) gene. All analyzed transformed lines had elevated levels of all POD isoforms. Three POD isoforms with pI values about 4.5, 4.8 and 8.4 and one additional pair of isoforms with pI value about 8.8 were separated from tissue extracts of all transgenic lines. Isoelectrofocusing pattern revealed the induction of one isoform of SOD with pI about 5.6 in all transgenic lines compared to non-transformed embryogenic tissue. These results indicate that the process of transformation may disrupt redox homeostasis in alflalfa tissues.