Overexpression of DnaK from a halotolerant cyanobacterium Aphanothece halophytica enhances the high-temperatue tolerance of tobacco during germination and early growth

• Published in: Plant science (Limerick) Vol. 160; no. 3; pp. 455 - 461
• Main Authors: Ono, K., Hibino, T., Kohinata, T., Suzuki, S., Tanaka, Y., Nakamura, T., Takabe, T.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 05.02.2001; Elsevier Science
• Subjects: Adaptation to environment and cultivation conditions; Agronomy. Soil science and plant productions; Aphanothece halophytica; Biological and medical sciences; DnaK; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; Heat stress; High temperature tolerance; Hsp70; Physical agents; Plant physiology and development; Transgenic tobacco; Varietal selection. Specialized plant breeding, plant breeding aims; Vegetative apparatus, growth and morphogenesis. Senescence; Hsp70; DnaK; Transgenic tobacco; High temperature tolerance; Aphanothece halophytica, A. halophytica; Heat stress; Aphanothece halophytica; Chl, chlorophyll; Seeds; Growth; Germination; Imbibition; Gene overexpression; High temperature; Nicotiana tabacum; Stress; Gene; Dicotyledones; Angiospermae; Cyanobacteria; Heat shock protein; Bacteria; Spermatophyta; Transgenic plant; Solanaceae; Experimental plant
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/S0168-9452(00)00412-X

DnaK1 from a halotolerant cyanobacterium Aphanothece halophytica, was overexpressed in the cytosol of tobacco. When the control and transgenic tobacco seeds were incubated at 27°C, more than 95% of the control and transgenic tobacco seeds germinated. However, at a high incubation temperature, 40°C, only 27% of the control seeds germinated whereas 82% of the transgenic seeds germinated. High temperature treatment during the imbibition of seeds delayed germination more in the control plants than in the transformants although the maximum percentage of germination was similar in both plants. The quantum yields of electron transport and plant elongation were higher in the transformant during high temperature treatment in young seedlings, but similar in older leaves. DnaK1 was detected in small amounts in seeds and its levels increased during germination. These data indicate that the expression of DnaK1 from a halotolerant cyanobacterium A. halophytica improved the tolerance to high temperature during germination and early growth.