HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Logan, B. A. Articles by Holaday, A. S. Search for Related Content PubMed Articles by Logan, B. A. Articles by Holaday, A. S. Agricola Articles by Logan, B. A. Articles by Holaday, A. S.

Transgenic overproduction of glutathione reductase does not protect cotton, Gossypium hirsutum (Malvaceae), from photoinhibition during growth under chilling conditions¹

²Biology Department, Bowdoin College, Brunswick, Maine 04011 USA; ³Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409-3131 USA

In some studies, tissues from plants that have been genetically transformed to overproduce antioxidant enzymes sustain less damage when abruptly exposed to short-term chilling in the laboratory. However, few studies have examined the performance of transgenic plants during longer-term growth under chilling conditions. We compared growth of transgenic cotton that overproduces glutathione reductase (GR+; 40-fold overproduction) to growth of the wild type in a controlled environment chamber as leaf temperature was lowered from 28° to 14°C over 9 d and for a subsequent 9-d period at 14°C. In wild-type and GR+ cotton, chilling temperatures resulted in decreased dark-adapted F_v/F_m (the ratio of variable to maximal fluorescence; a measure of maximum photosystem II quantum yield) and mid-light period photosystem II quantum yield, coupled with increased 1 – q_P (a nonlinear estimate of the reduction state of the primary quinone acceptor of photosystem II). The capacity for photosynthetic oxygen evolution decreased during the first portion of the chilling exposure, but recovered slightly during the second half. At no point during the chilling exposure did the performance of GR+ plants differ significantly from that of wild-type plants in any of the above parameters. The absence of an effect of GR overproduction under longer-term chilling may be explained, in part, by the fact that wild-type cotton acclimated to chilling by upregulating native GR activity.

Key Words: acclimation • antioxidants • chilling • chlorophyll fluorescence • cotton • glutathione reductase • Malvaceae • photoinhibition

This article has been cited by other articles:

				J. R. Mahan and S. A. Mauget Antioxidant Metabolism in Cotton Seedlings Exposed to Temperature Stress in the Field Crop Sci., September 23, 2005; 45(6): 2337 - 2345. [Abstract] [Full Text] [PDF]

				N. L. Lohrmann, B. A. Logan, and A. S. Johnson Seasonal Acclimatization of Antioxidants and Photosynthesis in Chondrus crispus and Mastocarpus stellatus, Two Co-Occurring Red Algae With Differing Stress Tolerances Biol. Bull., December 1, 2004; 207(3): 225 - 232. [Abstract] [Full Text] [PDF]

				M. Tausz, H. Sircelj, and D. Grill The glutathione system as a stress marker in plant ecophysiology: is a stress-response concept valid? J. Exp. Bot., August 1, 2004; 55(404): 1955 - 1962. [Abstract] [Full Text] [PDF]