ФОТОСИНТЕТИЧЕСКАЯ АКТИВНОСТЬ И СОДЕРЖАНИЕ ХЛОРОФИЛЛОВ В ПОБЕГАХ МХА HYLOCOMIUM SPLENDENS HEDW. В УСЛОВИЯХ ТЕМПЕРАТУРНОГО СТРЕССА

Abstract

Mosses are an attractive model for studying the mechanisms of plant adaptation to unfavorable environmental conditions. There is little information in the literature on the pigment composition and its role in stress resistance of mosses, although this topic is quite widely covered for higher vascular plants. Unfavorable environmental temperature is one stress factors with the strongest effect on plants, since photosynthesis, the main energy-supplying producing process in plants, is sensitive to temperature and often inhibited before other cellular functions are impaired. Chlorophyll is known to play a central role in the process of photosynthesis. In this regard, the aim of the present work was to study the response of the moss Hylocomium splendens Hedw. to temperature stress. The chlorophyll content and chlorophyll a fluorescence parameters in H. splendens shoots were investigated. Results showed that both elevated and negative temperatures decreased the content of chlorophyll a significantly, while, on the contrary, the content of chlorophyll b increased. It is interesting to note that the decrease in chlorophyll a under temperature stress was accompanied by an increase in the content of pheophytin a. The content of chlorophylls in the post-stress period did not recover to the control level. Temperature stress did not affect the maximum photochemical efficiency of photosynthesis, but the rate of electron transfer significantly decreased under the influence of low temperature. Thus, significant changes in the pigment composition of chlorophylls are not always accompanied by changes in fluorescence parameters to the same extent.