PLANT PHYSIOLOGY , Vol 108, Issue 4 1479-1486, Copyright © 1995 by American Society of Plant Biologists

WHOLE PLANT, ENVIRONMENTAL, AND STRESS PHYSIOLOGY

Violaxanthin Cycle Pigment Contents in Potato and Tobacco Plants with Genetically Reduced Photosynthetic Capacity

W. Bilger, J. Fisahn, W. Brummet, J. Kossmann and L. Willmitzer
Julius-von-Sachs-Institut fur Biowissenschaften, Lehrstuhl Botanik II, Mittlerer Dallenbergweg 64, 97082 Wurzburg, Germany (W. Bilger, W. Brummet)

The influence of photosynthetic activity on the light-dependent adaptation of the pool size of the violaxanthin cycle pigments (violaxanthin + antheraxanthin + zeaxanthin) was studied in leaves of wild-type and transgenic potato (Solanum tuberosum L.) and tobacco (Nicotiana tabacum L.) plants. The genetically manipulated plants expressed an antisense mRNA coding for the chloroplastic fructose-bisphosphatase. Chl fluorescence quenching analysis revealed that the transformed plants exhibited a greatly impaired electron transport capacity. Light-limited and light-saturated non-photochemical quenching was strongly enhanced in the mRNA antisense potato plants. After 7 d of adaptation at various high photosynthetic photon flux densities (PPFDs), the violaxanthin cycle pool size increased, with a progressive elevation in PPFD. The pool size was higher for transgenic potatoes than for wild-type plants at all PPFDs. This difference vanished when pool size was correlated with the PPFD in excess of photosynthesis, as indicated by the epoxidation state of the violaxanthin cycle. Contrasting results were obtained for tobacco; in this species, photosynthetic activity did not affect the pool size. We conclude that regulatory mechanisms exist in potato, by which photosynthetic activity can influence the violaxanthin cycle pool size. Furthermore, evidence is provided that this adaptation of the pool size may contribute to an improved photoprotection of the photosynthetic apparatus under high-light conditions. However, tobacco plants seem to regulate their pool size independently of photosynthetic activity.

This article has been cited by other articles:

				S. von Caemmerer, T. Lawson, K. Oxborough, N. R. Baker, T. J. Andrews, and C. A. Raines Stomatal conductance does not correlate with photosynthetic capacity in transgenic tobacco with reduced amounts of Rubisco J. Exp. Bot., June 1, 2004; 55(400): 1157 - 1166. [Abstract] [Full Text] [PDF]

				E. H. Murchie, S. Hubbart, Y. Chen, S. Peng, and P. Horton Acclimation of Rice Photosynthesis to Irradiance under Field Conditions Plant Physiology, December 1, 2002; 130(4): 1999 - 2010. [Abstract] [Full Text] [PDF]

				A. Makino, C. Miyake, and A. Yokota Physiological Functions of the Water-Water Cycle (Mehler Reaction) and the Cyclic Electron Flow around PSI in Rice Leaves Plant Cell Physiol., September 15, 2002; 43(9): 1017 - 1026. [Abstract] [Full Text] [PDF]

				M.-H. Montané, F. Tardy, K. Kloppstech, and M. Havaux Differential Control of Xanthophylls and Light-Induced Stress Proteins, as Opposed to Light-Harvesting Chlorophyll a/b Proteins, during Photosynthetic Acclimation of Barley Leaves to Light Irradiance Plant Physiology, September 1, 1998; 118(1): 227 - 235. [Abstract] [Full Text]