Seasonal changes in the content of dehydrins in mesophyll cells of common pine needles.
The appearance of dehydrins (DHNs) in cells is required for the development of cold resistance. DHNs are therefore considered specific markers of cold resistance by some authors. DHNs accumulate in plants concomitantly with a reduction of intracellular water content, and presumably protect membranes and proteins from damage caused by moisture loss. DHN content in pine needles increases in spring and autumn when moisture availability and temperatures are most unfavorable. The present work is focused on seasonal changes in DHN content in various mesophyll-cell compartments of pine (Pinus sylvestris L.) needles in association with changes in environmental factors. In spring, the number of thylakoid membranes per granum was lower than in summer and autumn. An increase in needle content of DHNs with approximate masses of 76, 73, 72, 35, and 17 kD in spring and autumn, associated with needle dehydration during this period, is shown here. The largest increase in DHN content was observed in spring, with the highest amount of DHNs presented in chloroplast membrane system including grana thylakoids, stromal thylakoids, and the two chloroplast envelope membranes and in cell walls. In the autumn, most DHNs were localized in chloroplasts and mitochondria.
Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch of Russian Academy of Sciences, Lermontova St., 132, POB 317, 664033, Irkutsk, Russia.
Natalia
N
Korotaeva
Anatolii
A
Romanenko
Galina
G
Suvorova
Maria V
MV
Ivanova
Lidia
L
Lomovatskaya
Gennadii
G
Borovskii
Victor
V
Voinikov
D002736:Chloroplasts / Q000378:metabolism / Q000648:ultrastructure; D003080:Cold Temperature; D058503:Mesophyll Cells / Q000378:metabolism / Q000648:ultrastructure; D041605:Pinus sylvestris / Q000502:physiology* / Q000648:ultrastructure; D018515:Plant Leaves / Q000502:physiology / Q000648:ultrastructure; D010940:Plant Proteins / Q000032:analysis / Q000378:metabolism*; D012621:Seasons; D020524:Thylakoids / Q000378:metabolism / Q000648:ultrastructure
D010940:Plant Proteins; C070556:dehydrin proteins, plant