|SHABALA, SERGEY - UNIV OF TASMANIA
|CUIN, TRACEY - UNIV OF TASMANIA
|PRISMALL, LUKE - UNIV OF TASMANIA
Submitted to: Planta
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2007
Publication Date: 12/1/2007
Citation: Shabala, S., Cuin, T.A., Prismall, L., Nemchinov, L.G. 2007. Expression of animal CED-9 anti-apoptotic gene in tobacco modifies plasma membrane ion fluxes in response to salinity and oxidative stress. Planta. 227(1):189-197.
Interpretive Summary: In this study we investigated properties of plants producing proteins that interfere with cell death during infection or other extreme environmental conditions. Our results demonstrated that expression of these proteins in plants increased tolerance to salt and to cell-damaging biological reactions with activated oxygen species and thus may be an efficient vehicle for enhancing stress resistance in economically important crops. This research uses an interdisciplinary approach, which combines two cutting-edge techniques - plant virus based expression technology and non-invasive measurements of ion transport in plants. It is expected that results of this study will be of interest to the wide spectrum of plant and animal researchers as well as to representatives of industry.
Technical Abstract: Apoptosis, one form of programmed cell death (PCD), plays an important role in mediating plant adaptive responses to the environment. Recent studies suggest that expression of animal anti-apoptotic genes in transgenic plants may be an efficient way of enhancing stress resistance in economically important crops. The underlying cellular mechanisms of this process remain unexplored. In this study, we investigated specific ion flux 'signatures' in Nicotiana benthamiana plants transiently expressing CED-9 anti-apoptotic gene and undergoing salt- and oxidative stresses. Using a range of electrophysiological techniques, we show that plant virus-based expression of CED-9 gene increased plant salt and oxidative stress tolerance and prevented stress-induced K+ efflux from mesophyll cells, so maintaining intracellular K+ homeostasis. We attribute these effects to the ability of CED-9 to control at least two types of K+-permeable channels; outward-rectifying depolarization-activating K+ channels (KOR) and non-selective cation channels (NSCC). To the best of our knowledge, this study is the first to link 'ion flux signatures' and mechanisms involved in regulation of PCD in plants.