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Protein Composition and Native State of Pigments of Thylakoid Membrane of Wheat Genotypes Differently Tolerant to Water Stress

I. M. Guseynova*, S. Y. Suleymanov, and J. A. Aliyev

Institute of Botany, National Academy of Sciences, Patamdar Shosse 40, AZ1073 Baku, Azerbaijan; fax: (994-12) 497-5045; (994-12) 438-1164; E-mail: aliyev_j@azeronline.com

* To whom correspondence should be addressed.

Received February 3, 2005; Revision received March 4, 2005
Protein composition and native state of chlorophylls were analyzed in two wheat (Triticum durum L.) genotypes with different tolerance to drought, Barakatli-95 (drought-tolerant) and Garagylchyg-2 (drought-sensitive), during water deficit. It is shown that the plants subjected to water deficit appear to have a slight increase in alpha- and beta-subunits of CF1 ATP-synthase complex (57.5 and 55 kD, respectively) in Barakatli-95 and their lower content in Garagylchyg-2. Steady-state levels of the core antenna of PS II (CP47 and CP43) and light-harvesting Chl a/b-apoproteins (LHC) II in the 29.5-24 kD region remained more or less unchanged in both wheat genotypes. The synthesis of 36 kD protein and content of low-molecular-weight polypeptides (21.5, 16.5, and 14 kD) were noticeably increased in the tolerant genotype Barakatli-95. Drought caused significant changes in the carotenoid region of the spectrum (400-500 nm) in drought-sensitive genotype Garagylchyg-2 (especially in the content of pigments of the violaxanthin cycle). A shift of the main band from 740-742 to 738 nm is observed in the fluorescence spectra (77 K) of chloroplasts from both genotypes under water deficiency, and there is a stimulation of the ratio of fluorescence band intensity F687/F740.
KEY WORDS: wheat, polypeptides, fluorescence, drought, chloroplast, adaptation

DOI: 10.1134/S000629790602009X