Grant, Olga M. and Brennan, Donal P. and Mellisho Salas, Carmen D. and Dix, Philip (2014) Impact of Enhanced Capacity to Scavenge Reactive Oxygen Species on Cold Tolerance of Tobacco. International Journal of Plant Sciences, 175 (5). pp. 544-554. ISSN 1058-5893

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Abstract

Premise of research. Reactive oxygen species (ROS) accumulate in plant tissues when the plant is exposed to stress, causing damage to cell structure and metabolism. Plants have a variety of mechanisms to prevent such damage, including a number of enzymes that scavenge ROS. The impact of specific enzymes, however, is as yet poorly understood. Methodology. The impact on plant tolerance to cold stress of enzymes involved in scavenging ROS was explored by comparing transplastomic tobacco lines overexpressing genes encoding glutathione reductase (GR), dehydroascorbate reductase (DHAR), glutathione-S-transferase (GST), and manganese superoxide dismutase, singly or in pairwise combinations, with nontransformed (NT) tobacco. Pivotal results. Chilling to 10°C resulted in less photoinhibition in lines overexpressing GR alone or in combination with GST, compared to NT tobacco, but more photoinhibition in lines overexpressing DHAR alone or in combination with GR. These differences were not, however, reflected in other indicators of stress. When chilled at 4°C, all lines showed similar damage to NT, except under relatively high photosynthetically active radiation, in which case photoinhibition was reduced in all transplastomic lines compared to NT. Growth over several weeks in a greenhouse was inhibited in the transplastomic lines when the duration included transient cool air temperatures. When optimal air temperature was maintained, growth over a similar duration was equal in transplastomics and NT tobacco. Conclusions. These experiments suggest a subtle interaction of enhanced ROS scavenging and tolerance of chilling stress.

Item Type:	Article
Additional Information:	The definitive published version of this article is available at DOI: 10.1086/675976 . Cite as Olga M. Grant, Donal P. Brennan, Carmen D. Mellisho Salas, and Philip J. Dix. "Impact of Enhanced Capacity to Scavenge Reactive Oxygen Species on Cold Tolerance of Tobacco." International Journal of Plant Sciences 2014; 175(5), 544-554.
Keywords:	ascorbate-glutathione cycle; chlorophyll fluorescence; chilling tolerance; photoinhibition; stress imaging; superoxide dismutase;
Academic Unit:	Faculty of Science and Engineering > Biology
Item ID:	6831
Identification Number:	https://doi.org/10.1086/675976
Depositing User:	Prof. Philip J. Dix
Date Deposited:	18 Jan 2016 17:04
Journal or Publication Title:	International Journal of Plant Sciences
Publisher:	University of Chicago Press
Refereed:	Yes
URI:
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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