Item – Theses Canada

OCLC number
46535717
Author
Harjanto, Erni Juniati,1962-
Title
Drought tolerance of transgenic alfalfa, Medicago sativa L.
Degree
M. Sc. -- University of Guelph, 1994
Publisher
Ottawa : National Library of Canada = Bibliothèque nationale du Canada, 1994.
Description
2 microfiches.
Notes
Includes bibliographical references.
Abstract
The Mn-SOD cDNA from Nicotiana plumbaginifolia was transformed into alfalfa (Medicago sativa L.) using Agrobacterium tumefaciens that targeted transit peptides to the chloroplast or mitochondria. In this study the chloroplast-targeted (RA3-ChlSOD-30), mitochondria-targeted (RA3-MitSOD-5), and control (RA3) plants were evaluated for their tolerance to drought stress by withholding water from vegetative plants in controlled environments. Both chloroplast- and mitochondria-targeted transformants had greater drought tolerance according to photosynthetic efficiency, electrolyte leakage, and regrowth parameters. Drought stress decreased soluble protein, increased the activity of total SOD, ascorbate peroxidase, and dehydroascorbate reductase and the level of both ascorbate and dehydroascorbate. Ascorbate peroxidase activity and total ascorbate content were higher in transgenic plants. These results demonstrate that oxidative stress is a consequence of drought stress and suggest that improvements may be made in drought tolerance of plants using genetic engineering.
ISBN
0315906863
9780315906860