Mammalian “Cell Suicide” Gene Enhances Plant Pathogen Resistance

Apoptosis, or programmed cell death (PCD), is an important requirement for the proper development of multicellular organisms. Orchestrated PCD helps a growing embryo reach its final form. It is also important in removing malfunctioning and virus infected cells, as well as in maintaining the number of cells constant in adult organisms. PCD is characterized by distinct biochemical and morphological features, such as changes in the cell membrane, cell shrinkage, destruction of nuclear membrane and DNA fragmentation. Evidences show that the PCD pathway exists in both plants and animals, although plants lack key animal apoptosis related genes.

Dong Suomeng and his colleagues from Nanjing Agricultural University in China generated transgenic tobacco lines overexpressing the mammalian apoptotic bax gene. The gene was placed under the control of the rice phenyalanine ammonia-lyase promoter. Ectopic expression of the transgene negatively affects the growth of the tobacco lines. It was shown, nonetheless, that bax plays an important role in pathogen response and plant development. The transgenic plants exhibited increased resistance to the pathogens Phytophthora and Ralstonia.

The paper published by Plant Cell Report is available at http://www.springerlink.com/content/507uujq20j24m75w/?p=81fa550d6f54498ab06e30211e8a5297&pi=0