Crop Biotech Update

Altering Respiratory Activity in GM Tobacco Using mDNA Fragments

February 24, 2012

Plant mitochondrial genomes (mtDNAs) are large and undertake recurrent recombination events. One of the characteristics that usually occur as a consequence of such events is the cytoplastic-male sterility. To date, the molecular basis of CMS is still to be explained, but it seems logical that changes in the respiration activities would lead to production of less pollen.

Felix Shaya of the Agricultural Research Organization in Israel, and other scientists conducted a study to analyze whether the expression of condensed fragments of michondrial genes (atp4, cox1 and rps3) may cause male sterility by controlling the biogenesis of the respiratory machinery.

Complementary DNA (cDNA) fragments equivalent to atp4f, cox1f and rps3f were cloned and introduced to tobacco plants using Agrobacterium-mediated transformation. Then the constructs were analyzed if they have an effect on mitochondrial activity and pollen fertility. Transgenic plants exhibited male sterility, which is strongly correlated with the expression of the recombinant fragments in the floral meristem. Further analysis on respiratory activities and protein profiles revealed that organellar complex I was changed in all transgenic plants studied.

For more information, read the research article at