首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Owen, J. H., Hetherington, A. M. and Wellburn, A. R. 1986. Inhibitionof respiration in protoplasts from meristematic tissues by abscisicacid in the presence of calcium ions.—J. exp. Bot. 38:498–505. A study was made of the influences of abscisic acid (ABA) andcalcium ions on mitochondrial respiration in protoplasts fromcells close to the basal intercalary meristem of light-grownbarley (Hordeum vulgare L. cv. Patty) seedlings. This respirationwas inhibited by ABA only when calcium ions were present. Thecalcium channel agonist BAY K8644 caused a significant inhibitionof protoplast dark respiration, similar to that observed usingABA and calcium, presumably because it imitated the action ofABA by increasing calcium influx into protoplasts. These resultssuggest that ABA increases the permeability of the plasmamembraneto calcium and that calcium acts as a second messenger to regulatemitochondrial respiratory activity and thus the very early eventsassociated with plastid and meristematic cell development. Key words: Abscisic acid, calcium, meristematic respiration  相似文献   

2.
Recent investigations have shown that abscisic acid (ABA) dependsupon the availability of Ca2+ for its action in certain systems.In order to check whether ABA requires Ca2+ to inhibit seedgermination, the effects of ABA, CaCl2, EGTA (a Ca2+ chelator)and lanthanum chloride and nifedipine (Ca2+ channel blockers),individually and in combination, on seed germination of Brassicajuncea L. cv. RLM-198 were studied. ABA inhibited germinationin a concentration dependent manner. ABA-induced inhibitionwas abolished with the lapse of time after application. Calciumneither affected germination nor altered the ABA-induced inhibition.EGTA. La3+ and nifedipine suppressed seed germination when testedindividually and further elevated the ABA effect, in a synergisticway, when applied simultaneously. They also prevented the time-dependentreduction in ABA-induced inhibition. The findings indicate thatCa2+ is not essential for ABA to cause germination inhibition. EGTA, Ca2+ channel blockers, abscisic acid, seed germination, Brassica juncea  相似文献   

3.
The conversion of 1-aminocyclopropane 1-carboxylic acid (ACC) to ethylene by hypocotyl segments of sunflower (Helianthus annuus L.) seedlings was inhibited by abscisic acid (ABA) and methyl jasmonate (Me-Ja), and this inhibitory effect increased with increasing concentration of both growth regulators. On the contrary, CaCl, enhanced ACC conversion to ethylene at the concentrations of 10-4 M and 5 x 10-4 M, however lower and higher concentrations had no significant action. CaCl, (5 x 10-4M) seemed to magnify the inhibition of the reaction induced by ABA, whereas it reduced (5 x 10-4M) and even abolished (10-3M) the inhibitory action of Me-Ja. The results obtained with a Ca2+ chelator (EGTA), a Ca2+ channel blocker (nifedipine) and calmodulin antagonists (W7 and TFP), given in association with ABA or Me-Ja, suggested that calcium was involved in the inhibition of ACC conversion to ethylene by ABA and Me-Ja through an interaction with calmodulin. However, the mechanism of action of the two growth regulators seemed to be different, since all treatments which resulted in a decrease in cytosolic Ca2+ concentration or in calmodulin action induced a decrease in the effect of ABA and an increase in the effect of Me-Ja.Abbreviations ABA abscisic acid - ACC 1-aminocyclopropane 1-carboxylic acid - EFE ethylene for enzyme - EGTA ethylene glycol-bis-2-aminoethyl tetraacetic acid - Me-Ja methyl jasmonate - NIF nifedipine - TFP trifluoperazine dihydrochloride - W7 N-(6-aminohexyl)5-chloro-l-naphthalenesulfonamide hydrochloride  相似文献   

4.
Astle, M. and Rubery, P. 1987. Carrier-mediated ABA uptake bysuspension-cultured Phaseolus coccineus L. cells: Stereospecificityand inhibition by ionones and ABA esters.—J. exp. Bot.38: 150–163. The substrate for the abscisic acid (ABA) carrier in Phaseoluscoccineus L. suspension-cultured cells is shown to be the (S)ABAenantiomer, Km = 1?0 mmol m–3. The methyl (MeABA) andphenyl (PheABA) esters of ABA inhibit carrier-mediated uptakeof ABA with half-maximal inhibition achieved at about 7?0 mmolm–3 and 10 mmol m–3 respectively: with (S)MeABAthis value is decreased to about 2?0 mmol m–3. There isno demethylation of radioactive MeABA by the cells during 5min incubations. Although MeABA reversibly inhibits the ABAcarrier, it is not a transport substrate: association of radioactiveMeABA with living cells is unaffected by non-radioactive MeABAor ABA and, by comparison with frozen-and-thawed cells, it isshown that the radioactivity remains extracellular. It is proposedthat MeABA binds to the carrier to form an abortive complexthat is not translocated. The terpenoid ABA analogue LAB 144143also inhibits carrier-mediated ABA uptake. At concentrationsup to about 20 mmol m–3 - and ß-ionone specificallyinhibit the ABA carrier with the half-maximal effect at about0?6 mmol m–3 ß-ionone. However, at higher iononeconcentrations, the uptake of ABA, indol-3-yl acetic acid andof 5,5-dimethyloxazolidine-2,4-dione (DMO) are all stimulated:this may reflect general permeabilization of the membrane toweak acids by ionone. Key words: Uptake carrier, abscisic acid, methyl and phenyl esters of ABA, ionone, Phaseolus coccineus L. suspension culture  相似文献   

5.
Neill, S. J., McGaw, B. A. and Horgan, R. 1986. Ethylene and1-aminocyclopropane-l-carboxylic acid production in flacca,a wilty mutant of tomato, subjected to water deficiency andpretreatment with abscisic acid —J. exp. Bot. 37: 535–541. Plants of Lycoperstcon esculentum Mill. cv. Ailsa Craig wildtype and flacca (flc) were sprayed daily with H2O or 2?10–2mol m–3 abscisic acid (ABA). ABA treatment effected apartial phenotypic reversion of flc shoots; leaf areas wereincreased and transpiration rates decreased. Leaf expansionof wild type shoots was inhibited by ABA. Indoleacetic acid (IAA), ABA and l-aminocyclopropane-l-carboxylicacid (ACC) concentrations were determined by combined gas chromatography-massspectrometry using deuterium-labelled internal standards ABAtreatment for 30 d resulted in greatly elevated internal ABAlevels, increasing from 1?0 to 4?3 and from 0?45 to 4?9 nmolg–1 fr. wt. in wild type and flc leaves respectively.Endogenous IAA and ACC concentrations were much lower than thoseof ABA. IAA content ranged from 0?05 to 0?1 nmol g–1 andACC content from 0?07 to 0?24 nmol g–1 Ethylene emanationrates were similar for wild type and flc shoots. Wilting of detached leaves induced a substantial increase inethylene and ACC accumulation in all plants, regardless of treatmentor type. Ethylene and ACC levels were no greater in flc leavescompared to the wild type. ABA pretreatment did not preventthe wilting-induced increase in ACC and ethylene synthesis. Key words: ABA, ACC, ethylene, wilting, wilty mutants  相似文献   

6.
Calcium ions contracted guard cell protoplasts (GCP) of Commelinacommunis L., being particularly effective within the concentrationrange of 0 to 0.2 mol m–3. Abscisic acid (ABA) in thepresence of EGTA, which chelates free Ca2+ in the medium, contractedGCP to a similar extent to Ca2+ alone or Ca2+ and ABA together.Similarly, ABA in the absence of free Ca2+ (i.e. an ABA/EGTAtreatment) inhibited K+-induced swelling of contracted GCP,as did Ca2+ alone or ABA and Ca2+ together. Lanthanum, a Ca2+channel blocker, prevented the contraction of GCP by Ca2+ buthad no effect if ABA was also present with Ca2+. The inhibitionof swelling of GCP by Ca2+ was also prevented by the presenceof lanthanum or verapamil (another Ca2+ channel blocker). These results indicate that Ca2+ and ABA can act independentlyof each other in contracting swollen GCP and in preventing K+-inducedswelling of contracted GCP of C. communis. If swelling and contractionof GCP are equivalent to stomatal opening and closure, respectively,the results do not support the hypothesis that ABA opens Ca2+channels in the plasma membrane of guard cells allowing Ca2+to enter the cells and, as a second messenger, to set in motionclosing processes. Key words: Abscisic acid, calcium, guard cell protoplasts, stomata  相似文献   

7.
The R- and S-enantiomers of racemic [2-14C]Me 1', 4'-cis-diolof abscisic acid have been separated by high performance liquidchromatography on an optically-active Pirkle column. R-[2-14C]-and S-[2-14C]abscisic acids, formed from the Me 1', 4'-cis-diolby oxidation and alkyline hydrolysis were fed to tomato shootsand the extracts analysed by reversed phase high performanceliquid chromatography. R-[2-14C]abscisic acid formed mainlythe abscisic acid glucose ester (ABAGE), abscisic acid l'-glucoside(ABAGS) and an uncharacterized conjugate. Dihydrophaseic acid4'-B-D-glucoside, the major metabolite of RS-abscisic acid intomato shoots, was found to be derived virtually exclusivelyfrom the natural, S-abscisic acid. Phaseic acid and conjugatesof abscisic acid were also found as products of the naturallyoccurring enantiomer. The resolution method was used to measurethe relative proportions of R and S enantiomers in the freeacid liberated from conjugates formed from RS-[2-14C]ABA fedto shoots. The ratios show an excess of the R-enantiomer: 5.8:1, ABAGE; 29.4: 1, ABAGE; 8.3: 1 for an uncharacterized conjugateand 6.1: 1 for the residual free [2-14C]ABA. Key words: ABA, HPLC, Tomato  相似文献   

8.
Protoplasts and vacuoles were isolated from immature apple fruit(Malus pumila Mill. cv. Golden Delicious). ATP-stimulated Ca2+uptake was identified in both protoplast vesicles and tonoplastvesicles. The apparent Km for Ca2+ of the tonoplast transportsystem was 43.4 µM. The pH optima were 7.2 and 6.7 forCa2+ transport by protoplast and tonoplast vesicles, respectively.Ca2+ transport in tonoplast vesicles was strongly inhibitedby the calmodulin antagonists fluphenazine and N-(6-aminohexyl)-5-chloro-l-naphthalensulfonamidehydrochloride (W-7), while N-aminohexyl)-l-naphthalensulfonamidehydrochloride (W-5) was relatively ineffective. Addition ofexogenous calmodulin stimulated transport by 35%. Ca2+ uptakewas inhibited by vanadate, but not by the ionophores carbonylcyanidem-chlorophenyl hydrazone (CCCP) or valinomycin. The resultsindicate that apple tonoplasts have a Ca2+ transport systemthat is driven by the direct hydrolysis of ATP, and may be calmodulindependent. 1Present address: Morioka Branch, Fruit Tree Research Station,Ministry of Agriculture, Forestry and Fisheries, Shimokuriyagawa,Morioka 020-01, Japan. To whom reprint requests should be addressed. (Received October 18, 1985; Accepted January 29, 1986)  相似文献   

9.
The role of abscisic acid (ABA) in controlling growth and developmenthas been studied in maize (Zea mays L.) coleoptile segments.Application of ABA reduces the elongation rate by about 50%and affects ion fluxes. In particular, proton extrusion is decreasedwhile potassium efflux is greatly enhanced. Apparently, ABAdoes not: seem to influence calcium influx from the apoplastinto the cytosol, but more likely it influences its efflux.Alteration of cytosolic calcium concentration may also be obtainedby increasing its release from internal stores. This possibilitymight be sustained by the increased hydrolysis of phosphatidylinositolupon ABA application. Change in the balance of ion fluxes shouldresult from regulation of transport mechanisms at the membranelevel and should produce changes in the transmembrane electricalpotential. The H+- ATPase and the ATP-dependent calcium transportactivities are both influenced by the treatment with ABA, –55%and –40%, respectively. Under these conditions [Ca2+]cytand pHcyt can be modified and, as a consequence of their regulation,they may play an important role in mediating the physiologicaland biochemical effects of ABA, acting as second intracellularmessengers. 1Research supported by National Research Council of Italy, SpecialProject RAISA, Sub-Project N. 2, Paper n. 2782.  相似文献   

10.
To a certain extent the flowering of Lemna paucicostata 6746is evoked in continuous light by application of abscisic acid(ABA) and CCC. Moreover, the action of the combined substancesappears in two separate concentration ranges. In the range ofABA 2?10–9 M/CCC 10–7–10–6 M floweringis initiated without inhibition of vegetative growth and proceedsonly in the presence of high intensity light and sucrose. Acombination of ABA 2?10–5 M/CCC 10–3M simultaneouslycauses a strong inhibition of frond multiplication. Here theeffect can be observed also under low intensity light conditionsand without sucrose in the medium. A range with flower inhibitingactivity lies between the two flower promoting concentrationranges. (Received November 16, 1972; )  相似文献   

11.
A calmodulin like domain protein kinase (CPK) homologue wasidentified in alfalfa and termed MsCPK3. The full-length sequenceof cDNA encoded a 535 amino acid polypeptide with a molecularweight of 60.2 kDa. The deduced amino acid sequence showed allthe conserved motifs that define other members of this kinasefamily, such as serine-threonine kinase domain, a junction regionand four potential Ca2+-binding EF sites. The recombinant MsCPK3protein purified from E. coli was activated by Ca2+and inhibitedby calmodulin antagonist (W-7) in in vitro phosphorylation assays.The expression of MsCPK3 gene increased in the early phase ofthe 2,4-D induced alfalfa somatic embryogenesis. Heat shockalso activated this gene while kinetin, ABA and NaCl treatmentdid not result in MsCPK3 mRNA accumulation. The data presentedsuggest that the new alfalfa CPK differs in stress responsesfrom the previously described homologues and in its potentialinvolvement in hormone and stress-activated reprogramming ofdevelopmental pathways during somatic embryogenesis. Key words: Medicago sativa, CPK, stress, 2,4-D, phosphorylation, somatic embryogenesis.  相似文献   

12.
Wheat (Triticum aestivum L.) embryos form in dynamically-regulatedovular environments. Our objectives were to improve developmentof cultured immature wheat embryos by simulating, in vitro,abscisic acid (ABA) levels and O2 tensions as found in wheatovules during zygotic embryogenesis. We characterized from intactwheat kernels embryo respiration, embryo morphology and embryoand endosperm + ABA levels at 13, 19 and 25 d post-anthesis(DPA). Young (13 DPA) embryos were then excised and culturedin vitro, where they were exposed to 0·2 or 2·Ommol m–3 ±ABA and 2.·1, 2·5 or 7·4mol m–3 (6, 7 and 21%, respectively) gaseous O2. At 6and 12 d in culture, + ABA levels, embryo respiration and embryomorphology were characterized by treatment. Thirteen-day-oldembryos from two different plant populations differed by 17-foldin initial ABA content. However, this difference did not affectprecocious germination in vitro, nor did it affect the amountof exogenous ABA required to reduce precocious germination by40%. In this respect, embryos from both populations were equallysensitive to exogenous ABA. Cavity sap O2 levels (2·1to 2·5 mol m–3) were much more effective in preventingprecocious germination of cultured embryos than were cavitysap levels of ABA (0·2 to 2·0 mmol m–3).The combination of physiological levels of both ABA and O2 largelynormalized DW accumulation and embryo morphology without alteringendogenous + ABA levels. Residual respiration of cultured embryoswas higher than that of embryos grown in situ, and was not influencedby the exogenous O2 and ABA treatments Key words: Abscisic acid, embryo development, oxygen tensions, respiration, wheat  相似文献   

13.
Responses of Commelina communis L. Guard Cell Protoplasts to Abscisic Acid   总被引:1,自引:0,他引:1  
Fitzsimons, P. J. and Weyers, J. D. B. 1987. Responses of Commelinacommunis L. guard cell protoplasts to abscisic acid.—J.exp. Bot. 38: 992–1001. Guard cell protoplasts (GCPs) isolated from the leaf epidermisof Commelina communis L. responded to abscisic acid (ABA) ina manner which was qualitatively and quantitatively similarto that of intact stomata. ABA inhibited swelling of GCPs underlow-CO2 conditions and swollen GCPs responded to the hormoneby shrinking. Both the absolute volume decrease and the initialrate of shrinking were commensurate with the extent and ratesof solute loss computed for ABA-treated intact, open stomata.This indicates that GCPs represent a suitable experimental systemfor studies of ABA-mediated solute fluxes. A radiotracer equilibrationmethod was developed for the rapid estimation of GCP osmoticvolume changes. Using this technique it was found that, on average,82% of the reduction in solute content caused by ABA treatmentwas due to the loss of K+. It is envisaged that electroneutralitymight be maintained during ABA-induced shrinkage of GCPs bynet inward proton movement leading to acidification of the vacuole. Key words: Abscisic acid, Commelina communis L., guard cells, protoplasts  相似文献   

14.
When cuttings of Tradescantia fluminensis stem were incubatedin distilled water, the buds located at the node grew into adventitiousroots. The root growth could be inhibited by calmodulin antagonists,trifluoperazine, chlorpromazine, compound 48/80 and calmidazolium,in a concentration-dependent manner. The divalent cation chelatorethyleneglycol-bis-(ß-aminoethyl ether)-N, N, N, N-tetraaceticacid had no effect, however, the intracellular chelator TMB-8completely inhibited root growth. The growth was also inhibitedby calcium ionophore A23187 [GenBank] , lanthanum, a competitive inhibitorof Ca2+ uptake and verapamil, a calcium channel inhibitor. AWestern blot of the adventitious root extract followed by immunostainingwith an anti-spinach calmodulin antibody clearly showed thepresence of calmodulin in this tissue. These results stronglysuggest the involvement of calmodulin and calcium in the growthof Tradescantia advenitious roots. 1A part of this work has been published in abstract form in"Molecular and Cellular Aspects of Calcium in Plant Development"(Editedby A.J.Trewavas, Plenum Publishing Co. 1986. 3Present address: Plant Laboratory , Kirin Brewerry Co. Ltd.,Kitsuregawa-cho, Tochigi-ken 329-14 ,Japan (Received May 2, 1987; Accepted September 17, 1987)  相似文献   

15.
High concentrations of cytosolic Na+ ions induce the time-dependent formation of an inactive state of the Na+/Ca2+ exchanger (NCX), a process known as Na+-dependent inactivation. NCX activity was measured as Ca2+ uptake in fura 2-loaded Chinese hamster ovary (CHO) cells expressing the wild-type (WT) NCX or mutants that are hypersensitive (F223E) or resistant (K229Q) to Na+-dependent inactivation. As expected, 1) Na+-dependent inactivation was promoted by high cytosolic Na+ concentration, 2) the F223E mutant was more susceptible than the WT exchanger to inactivation, whereas the K229Q mutant was resistant, and 3) inactivation was enhanced by cytosolic acidification. However, in contrast to expectations from excised patch studies, 1) the WT exchanger was resistant to Na+-dependent inactivation unless cytosolic pH was reduced, 2) reducing cellular phosphatidylinositol-4,5-bisphosphate levels did not induce Na+-dependent inactivation in the WT exchanger, 3) Na+-dependent inactivation did not increase the half-maximal cytosolic Ca2+ concentration for allosteric Ca2+ activation, 4) Na+-dependent inactivation was not reversed by high cytosolic Ca2+ concentrations, and 5) Na+-dependent inactivation was partially, but transiently, reversed by an increase in extracellular Ca2+ concentration. Thus Na+-dependent inactivation of NCX expressed in CHO cells differs in several respects from the inactivation process measured in excised patches. The refractoriness of the WT exchanger to Na+-dependent inactivation suggests that this type of inactivation is unlikely to be a strong regulator of exchange activity under physiological conditions but would probably act to inhibit NCX-mediated Ca2+ influx during ischemia. ischemia; cytosolic calcium concentration; cytosolic sodium concentration; cellular phosphatidylinositol-4,5-bisphosphate  相似文献   

16.
Previous papers have shown that abscisic acid can inhibit transportof ions across the root to the xylem vessels, resulting in reducedexudation from excised roots or inhibiting guttation from intactplants. However, it has not been established whether the inhibitionwas due to a reduction in salt transport (Js) or in permeabilityof the roots to water (Lp). This paper investigates the effectof ABA on Lp and Js separately. It is shown that Lp increasedin ABA and then fell, but was about the same as in control rootswhen transport was inhibited. The effect of ABA on exudationtherefore appeared to be mainly due to reduction in Js. Inhibitionof Js was also present in intact, transpiring plants and sowas not due to reduced water flow. The inhibition of ion releaseto the xylem affected Na+, Mg2+, Ca2+, and phosphate as wellas the major ion in the exudate, K+. It is concluded that ABAinhibits salt transport to the shoot by acting on ion transportinto the xylem, and not by reducing water flow coupled withsalt transport.  相似文献   

17.
A cell-free system prepared from exocarp of Citrus sinensisfruits converted [14C]-all-trans-ß-carotene into zeaxanthin,antheraxanthin, violaxanthin and abscisic acid (ABA). ABA wasunequivocally characterized by combined capillary GC-MS. (Received August 3, 1993; Accepted August 6, 1993)  相似文献   

18.
Biochemical properties, i.e. endogenous abscisic acid, proline,sugars, respiration, adenosine phosphates and adenylate energycharge, and growth and moisture content were measured duringthe development of seeds of Machilus thunbergii. As dry matteraccumulated in the embryo during development, moisture content,ABA, proline, respiration and sugars all declined. At maturity,the dry mass of the seeds failed to attain a plateau beforethe period of natural seed shedding; the axis and cotyledonsreached moisture contents of 58 and 45%, respectively. Dryingof immature seeds at 73% relative humidity and 25 °C for30 d resulted in a complete loss of viability at all developmentalstages tested with the exception of mature seeds that were ableto tolerate a 5% decrease in moisture content before germinationdeclined. ABA was detected in all embryos tested, with a maximum value16.·16 µg g-1 d. wt about midway through development.Although the presence of ABA induced no tolerance to desiccationof mature seeds, it did coincide with decreased content of waterin the developing seeds and decreased respiration. Desiccationdamage of M. thunbergii seeds occurred when moisture contentwas still high (45%) and this damage was not related to theabsence of oligosaccharides in the mature seeds. We concludethat developing embryos and mature seeds of M. thunbergii haveproperties common to many recalcitrant seeds, with seeds beingsensitive to desiccation at all stages, having a prominent ABApeak, little proline, lacking oligosaccharides, and specifically,little dormancy and a moderate rate of respiration of matureseeds (0·9 µmol O2 min-1 g-1 f. wt). Adenosinetriphosphate content and energy charge decreased from stagefour to stage eight of seed development, then increased againto 103 nmol g-1 d. wt and 0·73, respectively, in matureseeds. The moderate energy charge observed in mature seeds indicatesthat continuous metabolism is also a characteristic of recalcitrantseeds.Copyright 1995, 1999 Academic Press Machilus thunbergii, seed development, recalcitrant seed, abscisic acid, energy charge  相似文献   

19.
The mechanisms regulating the permeability of lens epithelial cell gap junctions in response to calcium ionophore or ATP agonist-mediated increases in cytosolic Ca2+ (Cai2+) have been investigated using inhibitors of calmodulin (CaM) and PKC. Cell-to-cell transfer of the fluorescent dye AlexaFluor594 decreased after the rapid and sustained increase in Cai2+ (to micromolar concentrations) observed after the addition of ionophore plus Ca2+ but was prevented by pretreatment with inhibitors of CaM but not PKC. In contrast, the delayed, transient decrease in cell-to-cell coupling observed after the addition of ATP that we have reported previously (Churchill G, Lurtz MM, and Louis CF. Am J Physiol Cell Physiol 281: C972-C981, 2001) could be prevented by either the direct or indirect inhibition of PKC but not by inhibition of CaM. Surprisingly, there was no change in the relative proportion of the different phosphorylated forms of lens connexin43 after this ATP-dependent transient decrease in cell-to-cell coupling. Although BAPTA-loaded cells did not display the ATP-dependent transient increase in Cai2+, the delayed, transient decrease in cell-to-cell dye transfer was still observed, indicating it was Cai2+ independent. Thus CaM-mediated inhibition of lens gap junctions is associated with sustained, micromolar Cai2+ concentrations, whereas PKC-mediated inhibition of lens gap junctions is associated with agonist activation of second messenger pathways that are independent of changes in Cai2+. calcium; connexin43; lens gap junctions  相似文献   

20.
Age-related Changes in Stomatal Response to Cytokinins and Abscisic Acid   总被引:2,自引:0,他引:2  
Kinetin and zeatin(100 mmol m–3)reversald the ABA-mediated(100mmol m-2)closure of stomata of young maize leaves but did notaffect stomatal apertures of these leaves when applied alone.As leaves aged, kinetin or zeatin alone promoted increased stomatalapertures, while abscisic acid (ABA) applied alone had a reducedeffect on stomata. Even with older leaves, cytokinins reversadthe effect of ABA on stomata. Maize, stomata, abscisic acid, kineusc, zeatin, Zea mays  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号