Role of calcium ions in phytochrome responses: an update

Roux, Stanley J.; Wayne, Randy; Datta, Neeraj

doi:10.1111/j.1399-3054.1986.tb02430.x

Cited by 76 publications

(38 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been shown that phytochrome controls Ca2+ fluxes in oat coleoptiles (9), Nitella (30) and Mougeotia (6, 29) leading Roux et al (21) to propose that conversion to Pfr promotes the influx of Ca2" from the cellular exterior to the cytoplasm.…”

Section: Discussionmentioning

confidence: 99%

Effects of Compounds Affecting Calcium Channels on Phytochrome- and Blue Pigment-Mediated Pulvinar Movements of Cassia fasciculata

Roblin¹,

Fleurat‐Lessard²,

Bonmort³

1989

Plant Physiol.

View full text Add to dashboard Cite

Verapamil and nifedipine, known as calcium channel blockers, inhibited the phytochrome-mediated movements induced on Cassia fasciculata leaflets by a light-off signal, whereas they had no effect on the 'blue' pigment-mediated movements induced by a light-on signal. LaCI3 inhibited both types of reactions, but the inhibition of light-induced opening needed a 10 times higher concentration than that of dark-induced closure. Bay K 8644, an activator of calcium channels, increased the rate of dark-induced closure, whereas it had no effect on the light-induced opening. These data suggest that calcium ions are not mobilized in the same way in the two types of movements: possibly from extemal stores in the phytochrome-mediated reacffon and from intemal stores in the 'blue' pigment-mediated reaction. MATERIALS AND METHODS Plant Growth ConditionsPlants of Cassiafasciculata Michx. were grown from seeds in a mixture of garden-earth, heath-mold, sand and peat (3:2:3:2 by volume). They were maintained in climate-controlled chambers at 26 ± 1°C and 65 ± 2% RH. White fluorescent light (Phytor LF 40 ACEC Charleroi, Belgium) was given at a photon fluence rate (400-700 nm) of 36 Mmole m-2s-at the apex of the plants according to two daily schedules. In set A, the light was provided from 7 to 21 h (normal photoperiodic cycle), and in set B, light was provided from 19 to 9 h (inverted photoperiodic cycle).In various plants, particularly in Leguminosae, leaf movements can be induced by transferring leaves from light to darkness or from darkness to light. The kinetics, energetics, and some reaction steps of these movements are beginning to be well known (22,23). These movements, brought about by motor organs (pulvini), are not the result of growth processes but involve reversible turgor variations driven by ionic migrations, namely K+ and Cl-, in the cortical parenchyma cells of the pulvini (24). Furthermore, on the basis of the inhibitory effect induced by chelatants (EDTA and EGTA) (4,13,19) and the promotive effect induced by the ionophore A 23187 (19), calcium is hypothesized to intervene in the regulation of the pulvinar movements. Results presented previously (19,20) suggest that calmodulin could be implicated in some way. The question raised now is to determine in what way the calcium ions are mobilized before forming the active complex with calmodulin and, in particular, from what stores they could be liberated following a stimulus. This problem is considered in the present investigation by use of compounds known to affect calcium channels in animal cells either through an inhibition (LaCl3, verapamil, nifedipine) or a promotion (Bay K 8644). Indeed, the existence of Ca2" channels in plants has been suggested by the identification of binding sites for Ca2" channel blockers (1,5,10). 'Supported by the Centre National de la Recherche Scientifique (URA 81). Experimental Light SourcesThe source for the blue light was high pressure mercury lamps (Philips SP 500 W); the emitted light was filtered through a blue glass filter (...

show abstract

Section: Discussionmentioning

confidence: 99%

Effects of Compounds Affecting Calcium Channels on Phytochrome- and Blue Pigment-Mediated Pulvinar Movements of Cassia fasciculata

Roblin¹,

Fleurat‐Lessard²,

Bonmort³

1989

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…Furthermore, Bay K-8644 promotes phytochromemediated Cassia fasciulata leaf movement (Roblin et al, 1989(Roblin et al, , 1990 and increases the velocity of the R-mediated Mougeotia scalaris Hassel chloroplast rotation (Russ et al, 1991). Most authors agree that phytochrome regulates transmembrane Ca2 + fluxes Moysset and Simon, 1989;Roux et al, 1986;Stenz and Weisenseel, 1986;Takagi and Nagai, 1988;Takagi et al, 1990;Hepler, 1984, 1985;Weisensee1 and Ruppert, 1977) via regulation of calciumchannel activity (Bosen, 1990;Bossen et al, 1988;Roblin et al, 1989;Tretyn, 1987;Tretyn et al, 1990a). Tretyn ef al.…”

Section: Phytochrome Control Of Ca2+ Fluxesmentioning

confidence: 99%

“…Photoconversion of phytochrome and ultimate photomorphogenetic responses appear to be connected by internal messenger(s). Calcium ions have been proposed as playing this role (Roux et al, 1986) as discussed above. This section reviews data concerning participation of second messengers in phytochrome action.…”

Section: Signal Transduction Chainsmentioning

confidence: 99%

The Role(s) of Calcium Ions in Phytochrome Action

Tretyn¹,

Kendrick

Wagner

1991

Photochem & Photobiology

View full text Add to dashboard Cite

“…Phytochrome is involved in this induction (8,18). Several phytochrome stimulated reactions are thought to be mediated through a rapid increase in cytosolic Ca2" concentration (14,15). For example, red light caused a change of chloroplast orientation in Mougeotia and concomitantly an increase in cytoplasmic "5Ca2" (3).…”

mentioning

confidence: 99%

Involvement of Calcium in the Photoperiodic Flower Induction Process of Pharbitis nil

Friedman¹,

Goldschmidt²,

Halevy³

1989

Plant Physiol.

View full text Add to dashboard Cite

EGTA, a specific Ca2+ chelator, inhibited the flowering response of Pharbitis nil when applied to the cotyledons immediately before the inductive dark period. Calcium sprayed 30 minutes after the EGTA blocked the effect of EGTA. The length of the critical dark period was increased both by EGTA and by LaCI3. The calmodulin antagonists W-7 and chlorpromazine also reduced the flowering response. On the other hand, A23187, a calcium ionophore, increased the flowering response. Both EGTA and A23187 were effective at certain times of the photoperiod but had almost no effect when applied at other times. The results indicate that the level of endogenous Ca2+ may be limiting for floral induction in Ph. nil. Ca2+ seems to play a role during the early stages of the inductive dark period.Pharbitis nil is a short-day plant which can be induced to flower by a single photoinductive dark period (8). Phytochrome is involved in this induction (8,18). Several phytochrome stimulated reactions are thought to be mediated through a rapid increase in cytosolic Ca2" concentration (14,15). For example, red light caused a change of chloroplast orientation in Mougeotia and concomitantly an increase in cytoplasmic "5Ca2" (3). Red light also promoted germination of Onoclea spores with a parallel increase in total intracellular calcium concentration (19). Those effects were reversed by FR' (3,19).A relationship between phytochrome-mediated induction of flowering and calcium level has not yet been demonstrated. We are aware of only one report on the possible involvement of Ca2" on the photoperiodic induction of flowering: the distilled water-induced inhibition of flowering in the SD plant Lemma perpusilla was partly reversed by the addition of Ca2" (6). In the present study we used EGTA, a specific Ca2" chelator, LaCl3, a calcium channel blocker, two calmodulin antagonists and the calcium ionophore A23187 to examine the possibility that a change in cytosolic Ca2" concentration might affect the floral photoinduction process. MATERIALS AND METHODSSeeds of Pharbitis nil Chois cv 'Violet' (Marutane Seed Co., Kyoto, Japan) were stirred with concentrated H2SO4 for 45 min, rinsed well, and imbibed for 24 h in running tap water. The seeds were sown in wet vermiculite at 1500 h and ' Abbreviations: FR, far red; NB, night break; W-7, N-(C-aminhexyl)5-chloro-l-naphthalene sulfonamide hydrochloride; chlorpromazine, 2-chloro-10-[3-dimethylaminopropyl]phenothiazine. transferred to a growth chamber at 24 ± 2°C with continuous light (17 W m-2, cool-white fluorescent; Tadiran, Israel). Induction treatments were routinely given on the 6th or 7th d as a 16 h dark period at 23C. Thereafter the plants were returned to continuous light at 24 ± 2°C. When desired NB of 10 min light (as above) were applied 8 h after the beginning of the dark period. EGTA (Sigma; aqueous solutions adjusted to pH 7.0 with NaOH), LaCl3 (Fluka), A23 187 (Calbiochem; prepared as 5 x 10-3 M stock solution in ethanol and kept in darkness at -20C) and the calmodulin antagonists W-7...

show abstract

Role of calcium ions in phytochrome responses: an update

Cited by 76 publications

References 20 publications

Effects of Compounds Affecting Calcium Channels on Phytochrome- and Blue Pigment-Mediated Pulvinar Movements of Cassia fasciculata

Effects of Compounds Affecting Calcium Channels on Phytochrome- and Blue Pigment-Mediated Pulvinar Movements of Cassia fasciculata

The Role(s) of Calcium Ions in Phytochrome Action

Involvement of Calcium in the Photoperiodic Flower Induction Process of Pharbitis nil

Contact Info

Product

Resources

About