Submitted to: Periodicum Biologorum
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2007
Publication Date: 7/1/2008
Citation: Uzelac, B., Popovic, Z., Mijovic, A., Smigocki, A.C., Ninkovic, S. 2008. Growth habit and photo-synthetic activity of shoot cultures of Medicago sativa L. transformed with the oryzacystatin II gene. Periodicum Biologorum. 110-231-235. Interpretive Summary: Modifying Crop plants woth genetic techniques can lead to safer and more profitable farming. The production of genetically engineered plants involves transferring a new gene (trait) of interest along with an antibiotic or herbicide resistance gene that is used as a tool to identify the modified plant. Introduction of such single-gene traits may also result in more complex agronomic traits such as altered growth habit and photosynthetic activity. Therefore, a thorough evaluation of the genetically engineered plant's growth habit, composition and performance should always be considered to exclude possible negative interactions. The present study was undertaken with alfalfa plantlets genetically engineered with a trait for insect tolerance and maintained in the laboratory under sterile conditions for several years. When compared to the unaltered controls, the engineered plantlets were shorter, had a bushy growth habit and exhibited a decrease in photosynthesis. Analysis of plant growth under laboratory conditions can help with the early selection of desirable agronomic characteristics in genetically engineered plants. This information will be of interest to scientists working on approaches for evaluating the effects of newly incorporated traits on the growth habit of genetically engineered plants.
Technical Abstract: In vitro maintained shoot cultures of alfalfa (Medicago sativa L. cv. Zajeÿarska 83) that were transformed with the oryzacystatin II (OCII) gene and propagated on growth regulator-free medium were subjected to analysis of morphological characteristics and photosynthetic activity. The most striking feature of transformed cultures was reduced apical dominance and adventitious root production. In comparison to the control shoots, main axis length was reduced to about 80 % and 33 % in OCII-1 and OCII-16 shoots, respectively. In addition, a general decrease in photosynthesis in transgenic shoots was also observed. When compared to the control, net photosynthesis was 14 % and 77 % in OCII-1 and OCII-16, respectively.