TWO cDNAs ENCODING MAIZE RUBISCO ACTI-VASE HAVE TWO DIFFERENT 3′UTRs

Abstract

Azerbaijan, dj-aliev@baku.ab.azIn a halotolerant green alga D.salzna, the photosystem I1 (PS 11) activity was somewhat inhibited while the photosystem I (PS I) activity was increased with salinity. Later, the distribution of excitation energy between two photosystems has been shown to be unaffected, and the operation of cyclic energy-storing pathway in PS I upon acclimation to high ionic stress was suggested. To find out whether or not the increased capacity of PS I electron flow under high salinities is correlated with an increased quantum yield of PS I photochemistry, the fluorescence technique was used. The chlorophyll fluorescence induction curves and the 77K fluorescence emission spectra were measured. The remarkable differences were observed between 77K fluorescence spectra of D.salina cells from low and high salt media. In D.salina cells cultivated at low salt media, the maximum fluorescence emission peak at 77K was observed at 686 nm, whereas in high salt media the maximum fluorescence emission peak shifted to 710 nm. The peak at 686 nm results from emission of chlorophyll aassociated with PS 11, whereas the emission peak at 710 nm associated with PS I. When the D.salinacel1 grown at low salt media (0.5 M NaCI) were transferred to high salt media (4 M NaCI), the intensity of emission peak at 686 nm decreased with the increase of emission peak at 710 nm. These data also suggest the activation of PS I mediated electron flow under high salt conditions.