Over-expression of StAPX in tobacco improves seed germination and increases early seedling tolerance to salinity and osmotic stresses.
Ascorbate peroxidase plays a key role in scavenging reactive oxygen species under environmental stresses and in protecting plant cells against toxic effects. The Solanum lycopersicum thylakoid-bound ascorbate peroxidase gene (StAPX) was introduced into tobacco under the control of the cauliflower mosaic virus 35S promoter. Transformants were selected for their ability to grow on medium containing kanamycin. RNA gel blot analysis confirmed that StAPX was transferred into the tobacco genome and StAPX was induced by salt and osmotic stresses in tomato leaves. Over-expression of StAPX in tobacco improved seed germination rate and elevated stress tolerance during post-germination development. Two transgenic lines showed higher APX activity and accumulated less hydrogen peroxide than wild-type plants after stress treatments. The photosynthetic rates, the root lengths, the fresh and dry weights of the transgenic lines were distinctly higher than those of wild-type plants under stress conditions. Results indicated that the over-expression of StAPX had enhanced tolerance to salt stress and osmotic stress in transgenic tobacco plants.
College of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China.
Wei-Hong
WH
Sun
Ming
M
Duan
De-Feng
DF
Shu
Sha
S
Yang
Qing-Wei
QW
Meng
D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000032:analysis; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D054712:Salinity; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development*; D013312:Stress, Physiological; D014026:Nicotiana / Q000187:drug effects* / Q000235:genetics
D018076:DNA, Complementary; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D018749:RNA, Plant; D002734:Chlorophyll; D006861:Hydrogen Peroxide; D010544:Peroxidases; D000077194:Chlorophyll A