Influences of External Factors
The effect of temperature on protoplasmic streaming has been studied for many years, going back as early as 1774 when the streaming was first discovered by Corti . It was, however, Nägeli (1860) who first studied in detail the influence of temperature on
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obtained in a glycerinated 'cell model' studied by HOFFMANN-BERLING (1954 a, b, 1955). As to the mechanism of the protoplasmic streaming being induced in the plant cell, there are still no detailed data, but it may also be reduced to the problem of the shift of the metabolic passway and that of the a.vailability of ATP for the ,streaming. All in all, the information gathered from the ,slime mould shows that what represents the direct energy source of the protoplasmic movement is not the mean value of the ,..., P level in the cell as a whole, but is the level of ,..., P at the place where the mechanochemical system exists, or at the seat of the generation of the motive force. If the ATP concentration there gets higher, the movement gets generally more active up to the optimum level. In any event, as the glycolytic process and the generation of the motive force of the protoplasmic movement occur in the ground milieu (hyaloplasm) of the cytoplasm, the energy obtained by the glycolytic process can be readily utilized for the movement; the energy obtained by respiration acquires its significance as an energy source fo'r the movement only when ATP is readily diffusible from mitochondria.
VII. Influences of External Factors 1. Temperature a) Relation between temperature and rate of streaming The effect of temperature on protoplasmic streaming has been studied for many years, going back as early as 1'2"74 when the streaming was first discovered by CORTI. It was, however, NAGEL! (1860) who first studied in detail the influence of temperature on the rate O'f prQtoplasmic flow 'On a quantitative basis. His data show that the rate of flow in the Nitella cell increases acco,rding to an eXPQnential function O'f tempera.ture. On the other hand, VELTEN (1876 a), who studied the tempera.ture effect on the speed of streaming in Chara, Vallisneria, and Elodea, found that the streaming increases linearly with temperature. The results obtained by LAMBERS (1925, 1926) in Characeae (Chara iodida, Nitella mucronata and N. translucens) show also the linearity of the temperature-velocity relation. LAMBERS' experiment further makes it clear that the rate in Nitella always has a constant value with constant temperature independently of whether the cell has been heated to that point from a lower temperature, O'r whether it has been cooled down to that point from a higher temperature. This means that there is no indlication of "hysteresis." ZURZYCKI (1951) studied anew the temperature effect on the streaming in the Elodea leaf. 005 calculated from the data of his experiment are rather irregular, but the data fit satisfactorily into BELEHR.4DEK'S formulation,
V= 4
~4 • a
The results obtained by ZURZYCICI are also in accordance with the
V: rate, t: temperature, a und b: constants (cf. data, a = 1.95 and b ~ 0.81.
BELEHRADEK 1929, 1935);
ZURZYCKI'S
Protoplasmatologia VIII, 3 a
N. Kamiya, Protoplasmic Streaming © Springer-Verlag in Vienna 1959
6
in
82
VITI, 3 a: N.
KAMIYA,
Protoplasmic Streaming
those of BEIKIRCH (1925), who st
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