FUNCTIONING OF THE PHOTOSYNTHETIC APPARATUS IN ALLELIC MUTANTS OF ARABIDOPSIS-THALIANA (L) HEYNH

We used the method of delayed luminescence to study the action of different allelic states of the flavi 1 gene that determine the yellowish-green color of mutant plants on functioning of the photosynthetic apparatus in Arabidopsis thaliana (L.) Heynh. Induction curves, light curves ,and temperature dependencies were analyzed. Allelic mutants exhibited deviations from the norm in content of Chl a and b, number of chloroplasts per cell, size of chloroplasts, number of PSII* reaction centers, photosynthetic rate per unit of leaf area, etc. However, no differences of PSII photochemical activity were detected in comparing allelic mutants with each other or with the norm. While exerting pleiotropic action on variability of a number of phenotypic traits, allelic mutations at the same time do not cause disturbances in the activity of PSII reaction centers. The energy supply available to the plants was consequently sufficient for full completion of their life cycle. In regard to thermostability of PSII, allelic mutants were less resistant than the starting form and were subdivided into groups with temperature maxima equal to 44-degrees-C and lying within the limits of 41-42-degrees.