Thermoluminescence study of photosystem II activity in Haberlea rhodopensis and spinach leaves during desiccation.
Thermoluminescence glow curve parameters were used to access the functional features of PS II in the Balkan endemic Haberlea rhodopensis. This representative of the higher desiccation-tolerant plants is unique for the European flora. An unusual high temperature of TL emission from Haberlea leaves after excitation by one flash at 5 degrees C was observed. The position of the main TL B band (S (2)Q (B)(-)) was at 45 - 47 degrees C, while this temperature was 30 - 32 degrees C in drought-sensitive mesophytic spinach. Consistent with the up-shift in TL emission, the lifetime of the S (2) state was also increased, showing a stabilization of charge storage in PS II complex in this resurrection plant. In addition, a part of PS II centres was less susceptible to DCMU. We consider the observed unusual TL characteristics of Haberlea rhodopensis reflect some structural modifications in PS II (especially in D1 protein), which could be related to the desiccation tolerance of this plant. This suggestion was supported by the different manner in which dehydration affected the TL properties in desiccation-tolerant Haberlea and desiccation-sensitive spinach plants.
Peeva
V
V
Acad. M. Popov Institute of Plant Physiology, Bulgarian Academy of Sciences, Sofia, Bulgaria. vili@obzor.bio21.bas.bg
Maslenkova
L
L
D000064:Acclimatization / Q000187:drug effects / Q000502:physiology*; D004237:Diuron / Q000494:pharmacology; D005060:Europe; D008027:Light; D019684:Magnoliopsida / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D045332:Photosystem II Protein Complex / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D018724:Spinacia oleracea / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D013696:Temperature; D014867:Water / Q000378:metabolism* / Q000494:pharmacology
D045332:Photosystem II Protein Complex; D014867:Water; D004237:Diuron