Journal of Plant Biochemistry and Biotechnology
Year : 2001, Volume : 10, Issue : 1
First page : ( 31) Last page : ( 37)
Print ISSN : 0971-7811.

Over-expression of Osmotin Induces Proline Accumulation and Confers Tolerance to Osmotic Stress in Transgenic Tobacco

Barthakur S, Babu V, Bansal K C*

National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute, New Delhi 110 012, India

*Corresponding author. E-mail: kailashbansal@hotmail.com Fax: 91-11-576 6420/582 3984

Received:  8  January,  2001.

Abstract

Osmotin has been implicated in conferring tolerance to drought and salt stress in plants. We have over-expressed the osmotin gene under the control of constitutive CaMV 35S promoter in transgenic tobacco, and studied involvement of the protein in imparting tolerance to salinity and drought stress. The transgenic plants exhibited retarded leaf senescence and improved germination on a medium containing 200mM NaCI. Further, the transgenics maintained higher leaf relative water content (RWC), leaf photosynthesis and free proline content than the wild type plants during water stress and after recovery from stress. When subjected to salt stress (200mM NaCI), the transgenic plants accumulated significantly more proline than the wild type plants. These results suggest the involvement of the osmotin-induced increase in proline in imparting tolerance to salinity and drought stress in transgenic plants over-expressing the osmotin gene.

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Key words

osmotin, transgenic, proline, salinity, drought.

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