Photophysiology of Turion Germination in Spirodela polyrhiza (L. ) SCHLEIDEN. Iv. Importance of Calcium and Calmodulin

Biochem. Physiol. Pt1anlcn 186, 209-210 (100Oi Gustav Fischer Verlag lena

Photophysiology of Turion Germination in Spirodela polyrhiza (L.) SCHLEIDEN. IV. Importance of Calcium and Calmodulin 2 2 KLAUS-J. ApPENRaTH I, REINHARD KUNGER , REINHARD WETZKER

and

HELMUT AUGSTEN 1

Friedrich-Schiller-Universitat Jena, 1) Sektion Biologie, Wissenschaftsbereich Pflanzenphysiologie, 2) Institut fUr Physiologische Chemie, Jena, G.D.R. Key Term Index: Calcium, Calmodulin, Germination, Phytochrome; Lemnaceae, Spirodela polyrhiza

Summary Light-grown as well as dark-grown (etiolated) turions of Spirodela polyrhiza are positively photoblastic. The phytochrome-mediated germination response requires supply with exogenous calcium (Ca2 +). Threshold value is 1.3 ± 0.3 [!M Ca2 +, half-maximal response is mediated by 16 ± 2 [!M Ca2 +. Ca2+ may be replaced in part by Sr2 +, but not by Mg2+. Furthermore, the addition of the Ca2 + -antagonists La3+ and Co2 + causes a complete inhibition of germination. Delayed addition of La3+ up to 72 h after the red light pulse results in a decreased, but still significant inhibition. Germination is also inhibited by the Ca2+ -channel blocker verapamil. On the other hand, stimulation of germination is observed without red light pulses if the Ca2 + -ionophore A 23187 is applied for 24 h. Complete inhibition of germination is caused by the calmodulin inhibitors chlorpromazine and trifluoperazine, and, besides, calmodulin was detected in the turions. Consequently, Ca2 + as well as calmodulin are involved in the phytochrome-mediated germination response of turions.

Introduction

Calcium has been recognized as an important regulator of cellular activity not only in animals but also in plants (HEPLER and WAYNE 1985; Raux et al. 1986). Concerning phytochrome-mediated responses Raux et al. (1986) have developed a hypothetical model on the basis of HAUPT and WEISENSEEL'S proposal (1976). In this model, Ca2 + and the Ca2 +binding protein, Cam, are essential links of the signal transduction chain. There is an increasing number of papers reporting on the importance of Ca2+ andlor Cam in phytochromemediated responses, i.e. concerning chloroplast rotation (HAUPT 1980), leaf unrolling (VINER et al. 1988), phototropism (HARTMANN and WEBER 1988), protoplast swelling (BassEN et al. 1988), nyctinastic movements (MOYSSET and SIMON 1989), L-leucine uptake (BASU et al. 1988) and spore germination (WAYNE and HEPLER 1984; lINa et al. 1989; SCHEUERLEIN et al. 1989). Spirodela polyrhiza (greater duckweed) forms turions, which are dormant immediately Abbreviations: Cam, calmodulin; DMSO, dimethylsulfoxide; D-turion, dark-grown (etiolated) turion; L-turion, light-grown turion; EGT A, ethyleneglycol-bis(~-aminomethylether)-N,N ,N' ,N'-tetraacetic acid; R, red light BPP 186 (1990) 4

209

after their formation (ApPENROTH et al. 1989 b). Responsiveness to phytochrome is developed during after-ripening (AUGSTEN et al. 1988; ApPENROTH et al. 1989b). The object of this study was (i) to examine the importance of specific cations and anions in the germination response of turions of Spirodela polyrhiza, which are, from a botanical point of view, far away from the extensively investigated fern spores, and (ii) to ask especially for calcium and Cam as possible links in the phytochrome-mediated signal-transduction chain.

Material and Methods Plant material and cultivation

Formation of dark-grown and light-grown turions (D-turions and L-turions, respectively) of Spirodela polyrhiza (L.) SCHLEIDEN, strains SJ, under phosphate-limited, mixotrophic conditions and cold after-ripening (stratification) to overcome dormancy are described elsewhere (ApPENROTH et al. 1989a; ApPENROTH et aI. 1989b). With the exception ofthe results presented in Fig. 1 turions were afterripened in complete nutrient medium. In most experiments, we have made use of the fact that D-turions are much more suitable photophysiological objects (AUGSTEN et al. 1988).

Germination and irradiation

Turions were irradiated for 1 min (D-turions) or 5 min (L-turions) with a saturating R pulse or not irradiated (dark-control sample) and transferred in amounts smaller than 75 turions (ApPENROTH et al. 1990) to 75 ml of the following nutrient solution: KHzP04 1.5 mM, Ca(N0 3 )z X 4HzO 1 mM, KN0 3 8 mM, MgS04 X 7HzO 1 mM, H3B03 5 [tM, MnCh X 4HzO 13 [tM, NazMo04 X 2H zO 0.4 [tM, Fe(III)-EDTA 25 [tM. In some experiments (cf. Fig. 1) specific ions were omitted. In these cases counter-ions were substituted by sodium salts or chlorides. The pH-values were re-adjusted with 0.1 M NaOH or HCl. Germination was carried out at 298.0 ± 0.5 K in darkness and percentage of germination was estimated 6 d (D-turions) or 13 d (L-turions) after the inducing R pulse. Turions were regarded as germinated if the new sprout was visible. Data were given as mean value ± standard error of the means. Each data point represents the irivestigation of 400-1000 turions. Light sources and irradiation conditions were described by AUGSTEN et al. (1988) and ApPENROTH et al. (1990). R (656 nm) fluence rate was 330 [tmol m- 2 S-I.

Calcium concentration Caz+ background concentration in the nutrient solution without Ca(N0 3h X 4 HzO-addition was determined by atom absorption spectrometry. Free Ca 2 + -concentrations in the presence of 1 mM Ca(N0 3h X 4HzO, 1 mM MgS04 X 7H20 and different concentrations of EGTA were calculated by using a computer programme and association constants as described by DINIUS et al. (1984). The pH of the nutrient solution was adjusted with NaOH to 7.2, which lowered germination percentage by 20%. Threshold value, half-maximal response concentration, and rate of increase of the dose-responserelationship were calculated by non-linear parameter fitting using a gaussian approximation. Errors indicated are standard devitions (ApPENROTH et al., 1989b).

Application of inhibitors and ionophore A 23187 If substances were used which tend to form precipitates with phosphate (i.e., lanthanum acetate), phosphate concentration in the nutrient solution was lowered to 30 [tM. The potassium level was readjusted by adding KCl. Chlorpromazine (Serva, Heidelberg, FRG) , verapamil, trifluoperazine and A 23187 (all Sigma, Munich, FRG) were presolved in DMSO.

210

BPP 186 (1990) 4

Preparatio/l and assay 01 «(/inlOdulil1 Turions (1.5 g fresh weight) were homogenized in Tris-HCI buffer (l00 mM, pH = 7.0) containing 25 mM KCI. After centrifugation (20 min, 20000 x g) the supernatant (about 5 ml) was extensively dialyzed against destilled water for 24 h. After re-centrifugation the supernatant was used for Cam assay (KLINGER et al. 1980) by measuring ATPase activity in Cam-depleted erythrocyte ghosts from human blood at pCa 2 + = 5.26. A single batch of ghosts was applied for calibration and for the sample with unknown amounts of Cam. The activity of the Ca2 + -ATPase was assayed by measuring inorganic phosphate liberated at 310 K and pH = 7.2 (KLINGER et al. 1980).

Results I. Importance of Specific Ions

To investigate the possible role of specific ions of the nutrient solution, red (R) pulse-induced germination ofD-turions was carried out in solutions with or without the ion in question. Results are shown in Fig. I. Besides the influence of nitrate and phosphate, the striking effect ofCa2+ is

n

I

i

~70 § ~ ~ 50

~I

I I

I

!

i

!

I I I I I I I I

I I I

Ii;

(C)

ill

I

I

I

I

C'i:. 30

10

I

I

ccrrPete

-M;/" -!hB03 -Mn 2 '

-tvbO/-

-k

4-

-Fe{fllJ fOTA

-50t

-N03-

-~PO,

-Ca 2 +

Fig. 1. Influence of the components of the complete nutrient solution on the germination, tested by omitting the specific ions indicated. Turions were after-ripened (4 weeks, 278 K) in the same nutrient solution as used for germination test. Red light pulse-induced germination of dark-grown turions.

evident. D- as well as L-turions are not able to germinate in the absence of exogenously applied Ca2+, even after extending the time after R pulses to 28 d (Table 1). Using carefully adjusted Ca 2 + -EGTA-buffers (DINJUS et al. 1984) we have determined the dependence of germination response on the free Ca2+ -concentration (Fig. 2). Half-maximal response is observed with 16 ± 2 IlM free Ca2+. With 1 IlM of free Ca2+ germination corresponds to zero, and the threshold value is about J.3 ± 0.3 IlM. This is in accordance with results when virtually Ca 2 + -free nutrient solutions are used (Table 1), because the Ca2 + -impurity of the nutrient solution without additional Ca 2 + was determined to 0.9 IlM. Consequently, the Ca2 + -background concentration is well below the threshold value, and the striking effectofCa 2 + on germination is evident simply by leaving out additional Ca 2 + . BPP 186 (1990) 4

211

r

x

x

x x

x

~60 c:

x

~

[)

S

~

(g4

x

20

70- 6

10-5

70- 4

70- 3

10-2

Ca2 + concentration (M) Fig. 2. Influence of the free calcium concentration on the red light pulse-induced germination of darkgrown turions. Free Ca 2 + -concentrations were adjusted using Ca2+ -EGTA-buffers (PH = 7.2) containing 1 mM Ca2+.

Furthermore, we have investigated whether or not the Ca 2 + -effect might be replaced by other ions of the second main group of elements. Mg2+ does not show any effect, but Sr2+ substitutes Ca2+ in part (Table 1). The Ca2 + -impurity of Sr(N03 h used was determined to be 3 X 10- 3 per cent. Consequently, the effect of Sr2+ cannot be explained as an impurity effect. We could not include experiments with barium beause of the insolubility in the presence of phosphate and sulfate.

2. Calcium Channel Blockers A blockade of the supposed Ca2+ -uptake by the turions should inhibit their germination response. Therefore, turion germination was carried out in complete nutrient solutions containing La3+ , Co2+ , or Mn2+ , which are known as Ca2+ influx blockers (VAN DER PAL et al. 1987; DUNHAM et al. 1983). Whereas addition of La3+ and Co2+ inhibited the germination response completely, Mn2+ did so only in part (Table 1). The inhibitory effect of La3+ was shown to be reversible: turion transfer to La3+ -free solution after 6 d results in a nearly undisturbed germination response in continuous white light (data not shown). According to HOSEY and LAZDUNSKI (1988) the antibioticum verapamil shows also Ca2+ -channel blocker activity. Consequently, the turion germination was inhibited in the presence of verapamil. Fig. 3 shows the dose-response-curve with a half-maximal response concentration of about 0.5 mM. Furthermore, the effect of a dark interval between R pulse and La3+ -addition was investigated. As shown in Fig. 4, delaying the time of La3+ -addition up to about 24 h after R pulse does not decrease the effectiveness of the channel blocker. Moreover, extending the dark period after R pulse to even 3 days does not remove the effect of La3+ completely. It should be noted, however, that the starting point of germination of D-turions is 1.9 ± 0.1 d 212

BPP 186 (1990) 4

Table I. Influence oleu /, 111111

(111

germil1ation percentage of dark- and light-grown turions investigated

by omitting Co 2 + FOIII Ihe /lutrient solution, bv Ca2+ -substitution (1 mM Mi + or Sr +) or by application of the Co 2 + -influx blockers La·li- (0.5 111M), C0 2 + (10 mM) and Mn2+ (10 mM) . Nutrient solution

Light conditions

Dark-grown turions

Light-grown turions

complete

R 0

94.0 ±1.7

41.0 ± 2.0 8.4 ± 0.9

-Ca2+*)

4.5 ± 09

R 0

0 0

0

-Ca2 + + Mg2+

R 0

0 0

0 0

-Ca2 + + Sr2+

R 0

26 .0

R 0

0 0

0 0

R 0

0

n.d .

0

n.d.

+La

H

+Co2 + +Mn2+

0

± 2.5 2.0 ± 1.0

R 0

n.d . n.d.

± 2.9

n.d.

1.7 ± 0.9

n.d.

58.6

R, red light pulse-induced germination ; 0 , dark germination ; n.d. , not detected . *) These samples were counted 28 d after transfer to germination flask.

9

f,,-:. -=- ___-

""""' 70 ~ c: a

15c: ~

5

'-

Q> \C)

30

10 0

10-6

10- 5

10 -4

70-3

Inhlbitor- Concentration (/VI) - - -_ Fig. 3. Influence of the calcium channel blocker verapamil and the calmodulin inhibitors chlorpromazine and trifluoperazine o n the red light pulse-induced germination of dark-grown turiOlls. BPP 186 (1990) 4

213

90 /

/

/

/

~

?R 70 c::

/

'-

/

/

/

.~

/

15

.!;: 50

E:

~


30

10

2

0

6

J

Time of La 3<;. addition (d)

..

Fig. 4. Influence of a dark interval between red light pulse (time zero) and addition of lanthanum acetate (0.5 mM) on the germination of dark-grown turions. Nutrient solution contained 0.5 mM Ca(N0 3h and 30 /-!M KH2 P04 •

after R pulse (ApPENROTH et al. 1989b), and that about 50 per cent of the turions are germinated after 3 d. Consequently, the germination response seems to be nearly arrested on the turion state at the time point of La3+ -addition.

3. Ionophore A 23187 In view of the supposed role of Ca 2 + in the transduction chain of turion germination, an experimentally induced increase in the intracellular Ca2+ -concentration might stimulate the germination response without R pulses. This was confirmed by experiments with the Ca2 +ionophore A 23187 (Table 2). Turions germinated to about 25 per cent in darkness if A 23187 was applied together with Ca(N03)z. However, germination induced by ionophore addition results in some developmental anomalies. Sprouts formed in this way are extremely small, Table 2. Influence of the calcium ionophore A 23187 (A; 1 !-!M) on dark germination of dark-grown turions. Control: I mM Ca(N0 3h. After time of treatment, turions were transferred into complete nutrient solution without A. Notice, however, germination anomalies after A-treatment (see text). Nutrient solution

Control + DMSO (0.1 %) + DMSO + A + DMSO + A + DMSO + A + DMSO + A - Ca2 +

214

BPP 186 (1990) 4

Time of treatment

Germination per cent

6d 1h 24 h 6d 24 h

0.3 0.3 0.9 24.3 0.7 0.3

± 0.3 ± 0.3 ± 0.3 ± 5.8 ± 0.5 ± 0.3

vItreous, and they show remarkable deformities. If the A 23187 -containing solution was Ca2+ free during the 24 h treatment and Ca2 + was not added before A 23187 was removed, the Ca2+ ionophore did not show any effect on germination response. The same holds true if the time of treatment with A 23187 was shortened (I h) or extended over the whole period of germination (6 d; Table 2).

4. Calmodulin Inhibitors Importance of Cam was shown in different phytochrome-mediated, Ca2+ -dependent responses (Raux et al. 1986; HEPLER 1988). On the other hand, phytochrome-mediated Lleucine uptake was shown to be Ca2+ -dependent, but Cam-independent (BASU et a1. 1988). To ask for a possible participation of Cam in turion germination response we investigated the influence of the drugs trifluoperazine and chlorpromazine, which are known as Cam inhibitors (WEISS and WALLACE 1980). Both inhibitors decrease the germination response (Fig. 3). The effective concentrations as well as the relative inhibitory activities lie in the same range as observed in other Cam-dependent systems. Presence of Cam was detected in turions of Spirodela polyrhiza. It amounts to 2.6 !lg Cam/ g fresh weight in L-turions and 5.9!lg Carnlg fresh weight in D-turions. Consequently, the Cam-content in turions is within the same range as estimated in other plant materials (WAGNER et a1. 1984).

Discussion Immediately after their formation turions are highly dormant (AUGSTEN et a1. 1988). Dormancy is broken by after-ripening and responsiveness towards phytochrome P fr is developing in the time course of this process (ApPENROTH et al. 1989 b). However, without exogenous Ca 2 + the phytochrome-mediated signal-transduction chain is effectively blocked at a further, up to now unknown step. This striking Ca 2 + -effect in turion germination is observed without chemical pretreatment of the turions and without lowering the free Ca2 + -level by the complexating agent EGT A. This is in contrast to results concerning the phytochrome-mediated spore germination of Onoclea sensibilis: Washing with EGT A (WAYNE and HEPLER 1984) or treatment with NaOCI (MILLER and WAGNER 1987) to extract Ca2+ from the spore coat are an indispensable prerequisite for inducing requirement for Ca2 +. The same holds true for Adiantum spores (IINO et al. 1989). The Ca 2 + -content in turions is about 1.5 mg/g dry weight (W. HERTEL, unpublished results). In contrast to spores, this high level does not sufficiently sustain the reaction leading to germination. The observation that even concentrations as low as 16 ± 2!lM Ca2 + (half-maximal response concentration) arc effective in turion germination show that this Ca 2 + action is no simple nutrient effect. The threshold of the external free Ca 2 + -concentration (1.3 ± 0.3 I-tM) for the germination response lies within the range, predicted by HEPLER and WAYNE (1985), to have physiological significance in induction. The external threshold is in similar to the intracellular threshold for the activation of the Ca2+ -binding protein, Cam (SCHARFF 1981). Our observations show that influx of Ca 2 + from nutrient solution plays a main role in germination response, whereas Ca2+ -release from supposed intracellular pools appears to be unimportant or at least insufficient. BPP 186 (1990) 4

215

The role of Ca 2 + in the germination response was also demonstrated in experiments in which Ca2+ was replaced in the nutrient solution by equimolar amounts of nitrate salts of Mg2+ and S~ + . In accordance with considerations concerning ion radii , ion-induced dipole interactions , coordination numbers and bond lengths of the ions (HEPLER and WAYNE 1985), Sr2 + fits the Ca+ requirement in part, whereas Mg2+ does not (Table 1). In establishing proof that uptake of Ca2+ is indeed involved in response, we have to consider three rules enunciated by JAFFE (1980): (i) The response should be accompanied by an increase in the intracellular Ca 2+ -concentration. (ii) Blockade of the increase in the intracellular Ca 2+ -concentration should inhibit the response. (iii) Generation of an increase in the intracellular Ca2+ -concentration should stimulate the response . Whereas up to now we could not demonstrate an increase in intracellular Ca 2 + -concentration (rule I), response is clearly inhibited if Ca2+ uptake is blocked, either by a Ca2+ -blocker (verapamil ; Fig. 3), or by Ca2+ -transport inhibitors (La3+ , Co2+ , Mn2+; Table 1). Thus , rule 2 holds, Ca 2 + uptake is important for the response. The ionophore A 23187 promoted the transport of Ca2 + with high affinity (LEHTONEN 1984). In consequence, the ionophore was apt to increase intracellular Ca2+ -concentrations (rule 3). As shown in Table 2, the dark germination of turions could be induced alone by addition of the Ca2+ -ionophore to the Ca 2 + -containing medium for 24 h. However, the fact has to be stressed that A 23187 results in new sprouts with developmental anomalies. Possibly, increase in intracellular Ca2+ -concentration does not replace all functions of phytochrome in inducing the germination response of turions . An alternative explanation is that A 23187 might induce some secondary effects. Whereas the presence of A 23187 for 1 h in the nutrient solution is too short to induce any germination response, the presence over the whole period of germination (6 days) seems to be too long. This latter effect is explained by cytotoxic effects of high Ca 2 + concentrations (HEPLER and WAYNE 1985). In Adiantum spores A 23187 does not induce germination (IINO et a1. 1989). Considering our results it seems to be possible that Ca 2 + could be transported through 2 Ca + -channels, which become open as an immediate result of P ff action (see HEPLER 1988). Binding studies with eH)-verapamil have indicated the existence of Ca 2 + -channels in the plasma membrane of plant cells (ANDREJAUSKAS et al. 1985). However, in this hypothetical model the effect of delayed La3+ -addition (Fig. 4) is difficult to explain as long as a direct effect of Pff is postulated. In spores of Onoclea La3+ -ions have to be present prior to or at least during irradiation with R. After it, La3 + -addition it without any effect (WAYNE and HEPLER 1984). In turion germination, however, La3+ is effective even at the starting point of germination or one day later. After 3 d (about 50 per cent of germination have already proceeded) La3+ inhibits about 50 per ceni of germination. That means, that La3+ stops germination kinetics in that state which is present at the very moment of La3+ -addition. Consequently, Ca 2 + has to be available over a more extended period of germination and its role seems to be rather complex . The germination response of Dryopteris spores was also inhibited by La 3 + as shown by SCHEUERLEIN et al. (1989). These authors demonstrated that Ca2+ acts after P ff had coupled and lost its control over the transduction chain. They concluded in accordance with IINO et al. (1989) that the direct interaction of Pff and Ca 2 + is not a step in the transduction chain initiated by P fr . Instead, Ca2 + was assumed to be a link in the Pfr-initiated transduction chain (DuRR and SCHEUERLEIN 1989). A similar conclusion was drawn concerning turion germination : (i) The Ca2+ -sensitive phase of turion germination lays within 216

BPP 186 (1990) 4

the Ptf-dependent period, (il) After removal of P rr by far-red light pulses there was no Ca2+sensitivity (ApPENROTH and AUGSTEN (990), An increase of the intracellular calcium concentration results in an activation of Cam in many cases (Roux et al. 1986), Inhibition of the turion germination by the Cam-inhibitors chlorpromazine and trifluoperazine indicates that also Cam may be a possible factor of the phytochrome-mediated germination response (Fig, 3). In this connection the presence of Cam in turions was also detectable. Experimental results showing that Mg2+ is not able to substitute for Ca2 +, whereas Sr2+ does so in part (Table I), correlate with the properties of these ions to form activated Cam-complexes (SCHARFF 1981). The importance of Cam in germination of the non-photoblastic seeds of radish was demonstrated (COCUCCI and NEGRINI 1988).

Acknowledgement The authors thank Mrs, BARBARA LIEBERMANN for skilful technical assistance.

References ANDREJAUSKAS, E., HERTEL, R" and MARME, D.: Specific binding of the calcium antagonist eH)verapamil to membrane fractions from plants. J. BioI. Chern. 260, 5411-5414 (1985). ApPENROTH, K,-J" and AUGSTEN, H,: Photophysiology of turion germination in Spirodela polyrhiza (L.) SCHLEIDEN, V. Demonstration of a calcium-requiring phase during phytochrome-mediated germination. Photochem. Photobiol. in press (1990), ApPENROTH, K,-J., HERTEL. W., and AUGSTEN, H.: Photophysiology of turion germination in SpirodeZa polyrhiza (L.) SCHLEIDEN. The cause of germination inhibition by overcrowding. BioI. Plant. in press (1990), ApPENROTH, K,-J" HERTEL, W" JUNGNICKEL, F., and AUGSTEN, H.: Influence of nutrient deficiency and light on turion formation in Spirodela poiyrhiza (L.) SCHLEIDEN. Biochem. Physiol. Pflanzen 184,395-403 (l989a). ApPENROTH, K.-J., OPFERMANN, 1., HERTEL, W" and AUGSTEN, H.: Photophysiology of turion germination in Spirodela po/yrhiza (L.) SCHLEIDEN. II. Influence of after-ripening on germination kinetics. J. Plant Physiol. 135,274-279 (1989b), AUGSTEN, H., KUNZ, E" and ApPENROTH, K, J.: Photophysiology of turion germination in Spirodela polyrrhiza (L.) SCHLEIDEN, I. Phytochrome-mediated responses of light- and dark-grown turions. J. Plant Physiol. 132.90-93 (1988), BASU, A., SETHI, U" and GUHA-MuKHERJEE, S,: Involvement of phytochrome in Ca2 + -dependent, calmodulin independent L-leucine uptake in Brassica, Plant Sci. 58, 25-33 (1988). BossEN, M. E., DASSEN. H. H, A., KENDRICK, R, E" and VREDENBERG, W. J.: The role of calcium ions in phytochrome-controlled swelling of etiolated wheat (Triticum aestivum L.) protoplasts, Planta 174, 94-100 (1988) COCUCCI, M., and NEGRINI. N,: Changes in the levels of calmodulin and of a calmodulin inhibitor in the early phases of radish (Raphanus sativus L.) seed germination. Effects of ABA and fusicoccin. Plant Physiol. 88,910-914 (1988). DINJUs, U., KLINGER. R" and WETZKER, R,: CaJEGTA solutions: Comparison between measured and calculated free calcium ion concentration in the micromolar range. Biomed, Biochim. Acta 43, 1067 - 1072 (1984) DUNHAM, D" ANDERSON, C, RICH, A. M" and WEISSMANN, G,: Stimulus-response coupling in sponge cell aggregation: Evidence for calcium as an intracellular messenger. Proc. Nat. Acad. Sci. 80,4756-4760 (1983) 15

BPP 186 (1990)

4

217

DURR, S., and SCHEUERLEIN, R.: Characterization of a specific calcium-requiring phase during phytochrome-mediated germination in spores of Dryopteris paleacea. European Symposium Photomorphogenesis in Plants. Book of abstracts, p. 32. Freiburg i. Br., FRG (1989). HARTMANN, E., and WEBER, M.: Storage of the phytochrome-mediated phototropism stimulus of moss protonemal tip cells. Planta 175, 39-49 (I988). HAUPT, W.: Sensory transduction and photobehaviour: Final considerations and emerging themes. In: Photoperception and sensory transduction in aneural organisms (Eds. LENCI, F., and COLUMBETTI, G.) pp. 397-404. Plenum Press, New York 1980. HAUPT, W., and WEISENSEEL, M. H.: Physiological evidence and some thoughts on localized responses, intracellular localization and action of phytochrome. In: Light and plant development. (Ed. SMITH, H.) pp. 63-74. Butterworths, Boston 1976. HEPLER, P. K.: Calcium and development. In: Proceedings of the XIV Int. Bot. Congr. Berlin 1987. (Eds. GREUTER, W., and ZIMMER, B.) pp. 225-240. Koeltz Scientific books, Konigstein 1988. HEPLER, P. K., and WAYNE, R. 0.: Calcium and plant development. Ann. Rev. Plant Physiol. 36, 397 -439 (1985). HOSEY, M. M., and LAZDUNSKI, M.: Calcium channels: Molecular pharmacology, structure and regulation. J. Membrane BioI. 104, 81-105 (1988). IINO, M., ENDO, M., and WADA, M.: The occurrence of a Ca2+-dependent period in the red-lightinduced late Gl phase of germinating Adiantum spores. Plant Physiol. 91, 610-616 (1989). JAFFE, L. F.: Calcium explosions as triggers of development. Ann. New York Acad. Sci. 339, 86-101 (1980). KAUSS, H.: Some aspects of calcium-dependent regulation in plant metabolism. Ann. Rev. Plant Physiol. 38,47-72 (1987). KLINGER, R., WETZKER, R., FLEISCHER, I., and FRUNDER, H.: Effect of calmodulin, Ca 2 + and M.:' ' f- on the (Ca 2 + + Mg 2 +)-ATPase of erythrocyte membranes. Cell Calcium 1, 229-240 (1980). LEHTONEN, J.: The significance of Ca2+ in the morphogenesis of Micrasterias studied with EGTA, verapamil, LaCb, and calciumionophore A 23187. Plant Sci. Lett. 33, 53-66 (1984). MOYSSET, L., and SIMON, E.: Role of calcium in phytochrome-controlled nyctinastic movements of Albizza lophanta leaflets. Plant Physiol. 90, 1108-1114 (1989). MILLER, J. H., and WAGNER, P. M.: Co-requirement for calcium and potassium in the germination of spores of the fern Onoclea sensibilis. Amer. J. Bot. 74, 1585-1589 (1987). Raux, S. J., WAYNE, R. 0., and DATTA, N.: Role of calcium ions in pyhtochrome responses: an update. Physiol. Plant. 66, 344-348 (1986). SCHARFF, 0.: Calmodulin- and its role in cellular activation. Cell Calcium 2, 1-27 (1981). SCHEUERLEIN, R., WAYNE, R., and Raux, S. J.: Calcium requirement of phytochrome-mediated fernspore germination: No direct phytochrome-calcium interaction in the phytochrome-initiated transduction chain. Planta 178,25-30 (1989). VAN DER PAL, R. H. M., BELDE, P. J. M., THEUVENET, A. P. R., PETERS, P. H. J., and BORSTPAUWELS, G. W. F. H. G.: Effect of ruthenium red upon Ca2 + and Mn2+ uptake in Saccharomyces cerevisiae. Comparison with the effect of La3+. Biochim. Biophys. Acta 902, 19-23 (1987). VINER, N., WHITELAM, Go" and SMITH, H.: Calcium and phytochrome control ofleafunrolling in darkgrown barley seedlings. Planta 175, 209-213 (1988). WAGNER, G., GROLIG, F., and ALTMULLER, D.: Transduction chain of low irradiance response of chloroplast reorientation in Mougeotia in blue and red light. Photobiochem. Photobiophys. Suppl. 183-189 (1987). WAGNER, V., VALENTIN, P., DIETER, P., andMARME, D.: Identification of calmodulin in the green alga Mougeotia and its possible function in chloroplast reorientional movement. Planta 162, 62-67 (1984). WAYNE, R., and HEPLER, P. K.: The role of calcium ions in phytochrome-mediated germination of spores of Onoclea sensibilis L. Planta 160, 12-20 (1984).

218

BPP 186 (1990) 4

WEISS, B. , and W AlLML . T . L. Mec hanism and pharmacological implications of altering calmodulin activity. In: Calcium ami cell function, VoL 1 (Ed. CHEUNG , W. Y.) pp. 329- 379. Academic press, New York-London-Toronto-Sydney-San Francisko 1980. Received February 12, 1990; accepted March I , 1990 Authors' address: Dr. K.-J. ApPENROT'H and Prof. Dr. H. AUGSTEN (Corresponding author), Department of Biology - Plant Physiology, Friedrich-Schiller-University, von-Hase-Weg 3, Jena, DDR - 6900; Dr. R. KLINGER and Dr. R. WETZKER, Institute of Physiological Chemistry, FriedrichSchiller-University, L6bderstra13e 3, lena , DDR - 6900.

Biochem . Physiol. Pflanzen 186, 219 (1990) Gustav Fischer Verlag lena

B uchbesprechungen AZZI, A., NALECZ, K. A., NALEC , M. J. , and WOJTCZAK, L. (Eds.): Anion Carriers of Mitochondrial Membranes. X, 381 S. , 147 Abb., zahlr. Tab. Springer-Verlag, Berlin-Heidelberg-New YorkLondon-Paris-Tokyo 1989. Preis: DM 128. Die Herausgeber hatten einen Themenkatalog erarbeitet, urn durch "invited Lectures" eine moglichst systematische Ubersicht iiber das Thema zu erhalten. Die daraus resultierenden Beitrage zu der im Juli 1988 in Zakopane (Polen) abgehaltenen Konferenz sind im vorliegenden Buch vollstandig publiziert. Die Themengruppen sind: (I) [solation and reconstitution of carriers, (11) Functional evidence and characterization of various carriers, (Ill) Porins, (IV) Uncoupling protein of brown adipose tissue, (V) Carriers and their cellular environment Die meisten der 31 Beitrage von ~l3 Autoren sind reich an experimentellen Details, aile enthalten ein Literaturverzeichnis. Man hatte sich eine noch starker verallgemeinernde und vertiefende Behandlung gewiinscht. Ein Sachverzeichnis fehlt. EBERHARD MULLER, Jena

MARKUS, M., MULLER, S. C, and NI COLlS, G. (Eds.): From Chemical to Biological Organization. Springer Series in Synergetics. Vol. 39. 358 S., 202 Abb. Springer-Verlag, Berlin-HeidelbergNewYork-London-Paris-Tokyo 1988. Preis OM 109. The idea to this hook deri ved from a sl1ccessful meeting at the Max-Planck-Institute in Dortmund in March 1987 organized to celebrate the 65th anniversary of the birthday of BENNO HESS , who pioneered the field of nonlinear phenomena in chemistry and biology. The thorough discussion on this topic was enlarged by addition of a few selected papers not presented at the meeting. The contributions are organized in 6 parts , i. e. (i) general concepts, (ii) chemical organization, (iii) biochemical organization, (iv) cellular and intercellular organization, (v) from complex cellular networks to the brain and (vi) ecological, epidemological and economical organization. The remarkable development of concepts and methods during the preceding 20 years are excellently documented in this book which for many years will serve as a valuable source of information for chemists, biologists, physicists, mathematicians or physicians active in this field. L. NOVER, Halle (Saa1e) 15 *

BPP 186 (1990) 4

219