Specific roles of α- and γ-tocopherol in abiotic stress responses of transgenic tobacco

被引:214
作者
Abbasi, Ali-Reza
Hajirezaei, Mohamad
Hofius, Daniel
Sonnewald, Uwe
Voll, Lars M. [1 ]
机构
[1] Univ Erlangen Nurnberg, Lehrstuhl Biochem, D-91058 Erlangen, Germany
[2] Inst Pflanzengenet & Kulturpflanzenforsch, D-06466 Gatersleben, Germany
关键词
D O I
10.1104/pp.106.094771
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
Tocopherols are lipophilic antioxidants that are synthesized exclusively in photosynthetic organisms. In most higher plants, alpha- and gamma-tocopherol are predominant with their ratio being under spatial and temporal control. While alpha-tocopherol accumulates predominantly in photosynthetic tissue, seeds are rich in gamma-tocopherol. To date, little is known about the specific roles of alpha- and gamma-tocopherol in different plant tissues. To study the impact of tocopherol composition and content on stress tolerance, transgenic tobacco (Nicotiana tabacum) plants constitutively silenced for homogentisate phytyltransferase (HPT) and gamma-tocopherol methyltransferase (gamma-TMT) activity were created. Silencing of HPT lead to an up to 98% reduction of total tocopherol accumulation compared to wild type. Knockdown of gamma-TMT resulted in an up to 95% reduction of alpha-tocopherol in leaves of the transgenics, which was almost quantitatively compensated for by an increase in gamma-tocopherol. The response of HPT and gamma-TMT transgenics to salt and sorbitol stress and methyl viologen treatments in comparison to wild type was studied. Each stress condition imposes oxidative stress along with additional challenges like perturbing ion homeostasis, desiccation, or disturbing photochemistry, respectively. Decreased total tocopherol content increased the sensitivity of HPT:RNAi transgenics toward all tested stress conditions, whereas gamma-TMT-silenced plants showed an improved performance when challenged with sorbitol or methyl viologen. However, salt tolerance of gamma-TMT transgenics was strongly decreased. Membrane damage in gamma-TMT transgenic plants was reduced after sorbitol and methyl viologen-mediated stress, as evident by less lipid peroxidation and/or electrolyte leakage. Therefore, our results suggest specific roles for alpha- and gamma-tocopherol in vivo.
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收藏
页码:1720 / 1738
页数:19
相关论文
共 86 条
[1]   Role of superoxide dismutases (SODs) in controlling oxidative stress in plants [J].
Alscher, RG ;
Erturk, N ;
Heath, LS .
JOURNAL OF EXPERIMENTAL BOTANY, 2002, 53 (372) :1331-1341
[2]   BASIC LOCAL ALIGNMENT SEARCH TOOL [J].
ALTSCHUL, SF ;
GISH, W ;
MILLER, W ;
MYERS, EW ;
LIPMAN, DJ .
JOURNAL OF MOLECULAR BIOLOGY, 1990, 215 (03) :403-410
[3]   Salt tolerance conferred by overexpression of a vacuolar Na+/H+ antiport in Arabidopsis [J].
Apse, MP ;
Aharon, GS ;
Snedden, WA ;
Blumwald, E .
SCIENCE, 1999, 285 (5431) :1256-1258
[4]   Plastoglobules are lipoprotein subcompartments of the chloroplast that are permanently coupled to thylakoid membranes and contain biosynthetic enzymes [J].
Austin, Jotham R., II ;
Frost, Elizabeth ;
Vidi, Pierre-Alexandre ;
Kessler, Felix ;
Staehelin, L. Andrew .
PLANT CELL, 2006, 18 (07) :1693-1703
[5]   Photo-oxidative stress in a xanthophyll-deficient mutant of Chlamydomonas [J].
Baroli, I ;
Gutman, BL ;
Ledford, HK ;
Shin, JW ;
Chin, BL ;
Havaux, M ;
Niyogi, KK .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2004, 279 (08) :6337-6344
[6]   Characterization of an Arabidopsis mutant deficient in γ-tocopherol methyltransferase [J].
Bergmüller, E ;
Porfirova, S ;
Dörmann, P .
PLANT MOLECULAR BIOLOGY, 2003, 52 (06) :1181-1190
[7]   Osmotic signaling in plants.: Multiple pathways mediated by emerging kinase families [J].
Boudsocq, M ;
Laurière, C .
PLANT PHYSIOLOGY, 2005, 138 (03) :1185-1194
[8]   Metabolic redesign of vitamin E biosynthesis in plants for tocotrienol production and increased antioxidant content [J].
Cahoon, EB ;
Hall, SE ;
Ripp, KG ;
Ganzke, TS ;
Hitz, WD ;
Coughlan, SJ .
NATURE BIOTECHNOLOGY, 2003, 21 (09) :1082-1087
[9]   Temporal and spatial control of gene silencing in transgenic plants by inducible expression of double-stranded RNA [J].
Chen, S ;
Hofius, D ;
Sonnewald, U ;
Börnke, F .
PLANT JOURNAL, 2003, 36 (05) :731-740
[10]   The role of homogentisate phytyltransferase and other tocopherol pathway enzymes in the regulation of tocopherol synthesis during abiotic stress [J].
Collakova, E ;
DellaPenna, D .
PLANT PHYSIOLOGY, 2003, 133 (02) :930-940