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 significantly improve a plant’s ability to tolerate a variety of biotic and abiotic stresses. 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 expression of CED-9 increased plant salt and oxidative stress tolerance by altering K+ and H+ flux patterns across the plasma membrane. Our data shows that PVX/CED-9 plants are capable of preventing 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). A possible scenario linking CED-9 expression and ionic relations in plant cell is suggested. 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.
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Carden DE, Walker DJ, Flowers TJ, Miller AJ (2003) Single-cell measurements of the contributions of cytosolic Na+ and K+ to salt tolerance. Plant Physiol 131:676–683
Chen SR, Dickman MB (2004) Bcl-2 family members localize to tobacco chloroplasts and inhibit programmed cell death induced by chloroplast-targeted herbicides. J Exp Bot 55:2617–2623
Chen Z, Newman I, Zhou M, Mendham N, Zhang G, Shabala S (2005) Screening plants for salt tolerance by measuring K+ flux: a case study for barley. Plant Cell Environ 28:1230–1246
Chen ZH, Zhou MX, Newman IA, Mendham NJ, Zhang GP, Shabala S (2007) Potassium and sodium relations in salinised barley tissues as a basis of differential salt tolerance. Funct Plant Biol 34:150–162
Chichkova NV, Kim SH, Titova ES, Kalkum M, Morozov VS, Rubtsov YP, Kalinina NO, Taliansky ME, Vartapetian AB (2004) A plant caspase-like protease activated during the hypersensitive response. Plant Cell 16:157–171
Clough SJ, Fengler KA, Yu I-C, Lippok B, Smith RK, Bent AF (2000) The Arabidopsis dnd1 ‘‘defense, no death’’ gene encodes a mutated cyclic nucleotide-gated ion channel. Proc Natl Acad Sci USA 97:9323–9328
Cuin TA, Shabala S (2005) Exogenously supplied compatible solutes rapidly ameliorate NaCl-induced potassium efflux from barley roots. Plant Cell Physiol 46:1924–1933
Cuin TA, Miller AJ, Laurie SA, Leigh RA (2003) Potassium activities in cell compartments of salt-grown barley leaves. J Exp Bot 54:657–661
Demidchik V, Shabala SN, Coutts KB, Tester MA, Davies JM (2003) Free oxygen radicals regulate plasma membrane Ca2+ and K+-permeable channels in plant root cells. J Cell Sci 116:81–88
Dickman MB, Park YK, Oltersdorf T, Li W, Clemente T, French R (2001) Abrogation of disease development in plants expressing animal antiapoptotic genes. Proc Natl Acad Sci USA 98:6957–6962
Gulbins E, Jekle A, Ferlinz K, Grassme H, Lang F (2000) Physiology of apoptosis. Am J Physiol Renal Physiol 279:F605–F615
Hatsugai N, Kuroyanagi M, Yamada K, Meshi T, Tsuda S, Kondo M, Nishimura M, Hara-Nishimura I (2004) A plant vacuolar protease, VPE, mediates virus-induced hypersensitive cell death. Science 305:855–858
Hughes FM, Cidlowski JA (1999) Potassium is a critical regulator of apoptotic enzymes in vitro and in vivo. Adv Enzyme Regul 39:157–171
Huh G-H, Damsz B, Matsumoto TK, Reddy MP, Rus AM, Ibeas JI, Narasimhan ML, Bressan RA, Hasegawa PM (2002) Salt causes ion disequilibrium-induced programmed cell death in yeast and plants. Plant J 29:649–659
Katsuhara M, Kawasaki T (1996) Salt stress induced nuclear and DNA degradation in meristematic cells of barley roots. Plant Cell Physiol 37:169–173
Khurana SMP, Pandey SK, Sarkar D, Chanemougasoundharam A (2005) Apoptosis in plant disease response: a close encounter of the pathogen kind. Curr Sci 88:740–752
Lam E, Kato N, Lawton M (2001) Programmed cell death, mitochondria and the plant hypersensitive response. Nature 411:848–853
Li W, Dickman MB (2004) Abiotic stress induces apoptotic-like features in tobacco that is inhibited by expression of human Bcl-2. Biotechnol Lett 26:87–95
Lincoln JE, Richael C, Overduin B, Smith K, Bostock R, Gilchrist DG (2002) Expression of the antiapoptotic baculovirus p35 gene in tomato blocks programmed cell death and provides broad-spectrum resistance to disease. Proc Natl Acad Sci USA 99:15217–15221
Maathuis FJM, Amtmann A (1999) K+ nutrition and Na+ toxicity: the basis of cellular K+/Na+ ratios. Ann Bot 84:123–133
Marschner H (1995) Mineral nutrition of higher plants, 2nd edn. Academic, London
McKersie BD, Hucl P, Beversdorf WD (1982) Solute leakage from susceptible and tolerant cultivars of Phaseolus vulgaris following ozone exposure. Can J Bot 60:73–78
Mitsuhara I, Malik KA, Miura M, Ohashi Y (1999) Animal cell-death suppressors Bcl-x(L) and CED-9 inhibit cell death in tobacco plants. Curr Biol 14:775–778
Newman IA (2001) Ion transport in roots: measurement of fluxes using ion-selective microelectrodes to characterize transporter function. Plant Cell Environ 24:1–14
Panayiotidis MI, Bortner CD, Cidlowski JA (2006) On the mechanism of ionic regulation of apoptosis: would the Na+/K+-ATPase please stand up? Acta Physiol 187:205–215
Pang JY, Zhou MX, Mendham N, Shabala S (2004) Growth and physiological responses of six barley genotypes to waterlogging and subsequent recovery. Aust J Agric Res 55:895–906
Pennell RI, Lamb C (1997) Programmed cell death in plants. Plant Cell 9:1157–1168
Qiao J, Mitsuhara I, Yazaki Y, Sakano K, Gotoh Y, Miura M, Ohashi Y (2002) Enhanced resistance to salt, cold and wound stresses by overproduction of animal cell death suppressors Bcl-xL and CED-9 in tobacco cells—their possible contribution through improved function of organella. Plant Cell Physiol 43:992–1005
Rojo E, Martin R, Carter C, Zouhar J, Pan SQ, Plotnikova J, Jin HL, Paneque M, Sanchez-Serrano JJ, Baker B, Ausubel FM, Raikhel NV (2004) VPE gamma exhibits a caspase-like activity that contributes to defense against pathogens. Curr Biol 14:1897–1906
Scholthof HB, Scholthof KBG, Jackson AO (1996) Plant virus gene vectors for transient expression of foreign proteins in plants. Annu Rev Phytopathol 34:299–323
Shabala L, Cuin TA, Newman IA, Shabala S (2005) Salinity-induced ion flux patterns from the excised roots of Arabidopsis sos mutants. Planta 222:1041–1050
Shabala S (2000) Ionic and osmotic components of salt stress specifically modulate net ion fluxes from bean leaf mesophyll. Plant Cell Environ 23:825–837
Shabala S, Babourina OK, Newman IA (2000) Ion-specific mechanisms of osmoregulation in bean mesophyll cells. J Exp Bot 51:1243–1253
Shabala S, Demidchik V, Shabala L, Cuin TA, Smith SJ, Miller AJ, Davies JM, Newman IA (2006) Extracellular Ca2+ ameliorates NaCl-induced K+ loss from Arabidopsis root and leaf cells by controlling plasma membrane K+−permeable channels. Plant Physiol 141:1653–1665
Shabala S, Newman IA, Morris J (1997) Oscillations in H+ and Ca2+ ion fluxes around the elongation region of corn roots and effects of external pH. Plant Physiol 113:111–118
Shabala S, Shabala L, Van Volkenburgh E (2003) Effect of calcium on root development and root ion fluxes in salinised barley seedlings. Funct Plant Biol 30:507–514
Smethurst CF, Shabala S (2003) Screening methods for waterlogging tolerance in lucerne: comparative analysis of waterlogging effects on chlorophyll fluorescence, photosynthesis, biomass and chlorophyll content. Funct Plant Biol 30:335–343
Watanabe N, Lam E (2004) Recent advance in the study of caspase-like proteases and Bax inhibitor-1 in plants: their possible roles as regulator of programmed cell death. Mol Plant Pathol 5:65–70
Xu P, Rogers SJ, Roossinck MJ (2004) Expression of antiapoptotic genes bcl- xL and CED- 9 in tomato enhances tolerance to viral-induced necrosis and abiotic stress. Proc Natl Acad Sci USA 101:15805–15810
Zhu JK (2002) Salt and drought stress signal transduction in plants. Annu Rev Plant Biol 53:247–273
Zimmermann S, Ehrhardt T, Plesch G, Mueller-Roeber B (1999) Ion channels in plant signaling. Cell Mol Life Sci 55:183–203
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This work has been supported by the ARC Discovery and Tasmanian Institute of Agricultural Research grants (S.S.) and by the United States Department of Agriculture, Agricultural Research Service (L.N.).
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Shabala, S., Cuin, T.A., Prismall, L. et al. Expression of animal CED-9 anti-apoptotic gene in tobacco modifies plasma membrane ion fluxes in response to salinity and oxidative stress. Planta 227, 189–197 (2007). https://doi.org/10.1007/s00425-007-0606-z
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DOI: https://doi.org/10.1007/s00425-007-0606-z