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1.
During the ripening stage of barley and rice, the sink activitywas defined as the dry matter increase per units sink size,leaf area and time, as follows: NAR = A.SinkW+NAR', where NAR is the net assimilation rate (g d.wt dm2d1);A is the sink activity [g d.wt g1d.wt (ear) dm2d1]; Sink W is ear wt per plant at heading (g d.wt);and NAR' is net assimilation rate excluding the assimilate ofsink organ (g d.wt dm2 d1). Plant material with 16 combinations of mutually different sink(ear) and source (leaf) size were produced at heading for eachcrop: parts of each leaf and ear were removed to produce fourgrades in barley, and also a part of each leaf was removed producingfour grades for four rice varieties showing different ear size.NAR and NAR' were determined during 26 and 21 d in barley andrice after heading, respectively. Sink activity (A), representedas the assimilation rate induced by the sink organ, was estimatedfrom the relationship between SinkW and NAR using the previousequation. The sink activity was significantly higher in ricewith a value of 00.028 g d.wt g1 d.wt (ear) dm2d1 vs. 00.0017 in barley, suggesting that therelative role of leaves for grain filling is considerably higherin rice than in barley. The sink activity obtained in the studymight be introduced into a model to predict the yields of barleyand rice. Hordeum vulgare L, barley, Oryza saliva L, rice, dry matter, NAR, sink, source, sink activity, model 相似文献
2.
Guttation was used as a non-destructive way to study the flowof water and mineral ions from the roots and compared with parallelmeasurements of root exudation. Guttation of the leaves of barley seedlings depends on age andon the culture solution. Best rates of guttation were obtainedwith the primary leaves of 6- to 7-day-old seedlings grown onfull mineral nutrient solution. The growing leaf tissue becomessaturated with K+ below 1.5 mM K+ in the medium, whereas K+concentration in the guttated fluid still increases furtheras K+ concentration in the medium is raised. At 3 mM K+ averagevalues of guttation were 1.42.4 mm3 h1 per plantwith a K+ concentration of 1020 mM; for exuding plantsthe flow was 4.27.6 mm3 h1 per plant and K+ concentration3555 mM. Abscisic acid (ABA) at 106 to 104 M 02h after addition to the root medium increased volume flow ofguttation and exudation and the amount of K+ exported. Threeh after addition of ABA both volume and amount of K+ were reduced.There was an ABA-dependent increase in water permeability (Lp)of exuding roots shortly after ABA addition. Later Lp was decreasedby 35 per cent and salt export by 60 per cent suggesting aneffect of ABA on salt transport to the xylem apart from itseffect on Lp. Benzyladenine (5 x 108 to 105 M)and kinetin (5 x 106 M) progressively reduced volumeflow and K+ export in guttation and exudation and reduced Lp. Guttation showed a qualitatively similar response to phytohormonesas found here and elsewhere using exuding roots. Hordeum vulgare L., barley, guttation, abscisic acid, cytokinins, benzyl adenine, kinetin 相似文献
3.
Studies on the Movement of Water Through Apple Trees 总被引:12,自引:0,他引:12
Resistances to the flow of water through young potted appletrees were estimated by measuring the transpiration rate oftrees with and without root systems. Root system resistanceswere obtained by difference. Whole-plant resistances were ofthe order 10 x 1013 Pa s m3 and there was some evidencethat root resistances (Rr) varied with transpiration rate; theratio Rr:Rx (where Rx is resistance to water flow in the stemsystem) altered from 2:1 at relatively high transpiration ratesto 1:1 at lower rates. The trunk of a 9-year-old orchard tree (trunk diameter {smalltilde}7 cm, height {small tilde}2.5 m) was cut under water andestimates of the flow resistances in this tree were obtained.These were much lower than the resistances to flow in the pottedtrees. Capacitance (defined as the change in stored water content perunit change in plant water potential) values were calculatedfor the small trees and the large tree from measurements ofweight and water potential changes after the trees were removedfrom water. They were very similar on a weight basis (approx.2.0 x 108 kg kg1 Pa1). Leaf capacitancevalues ({small tilde}1 x 108 kg Pa1 m2)were also obtained. Stomatal conductances decreased with water potential and increasedwith short-wave radiation, but the relationships were not definitive.Estimates of boundary layer conductance in a greenhouse (verylow wind speeds) were of the same order ({small tilde}5 mm s1)as values obtained previously. 相似文献
4.
1. Photophosphorylation was measured with spinach grana sampleswashed by 0.8 M Tris buffer at pH 8.0, which no longer catalyzedthe ferricyanide and NADP HILL reactions with water as the electrondonor. The photophosphorylation with the reaction mixture containing2 104 M 2,6-dichlorophenol indophenol (DCPI) plus above2 103 M ascorbate as the electron donor system insteadof water under anaerobic conditions was, in the most part, dependenton the addition of both PPNR (a nonheme iron protein requisitefor photosynthetic pyridine nucleotide reduction ; spinach ferredoxin)and NADP as the electron acceptor system. However, when ascorbateconcentration only was lowered to 2 104 M, the entirephotophosphorylation proceeded, even in the absence of the electronacceptor system. 2. When the NADP added in the reaction mixture had been reducedby glucose-6-phosphate and glucose-6-phosphate dehydrogenasebefore illumination, the photophosphorylation with 2 104M DCPI plus 6.7 103 M ascorbate decreased to aboutthe same rate as that obtained without NADP. 3. The time course for photophosphorylation in the presenceof NADP was consistent with the time course for the photoreductionof NADP: On the complete reduction of NADP, the photophosphorylationstopped. 4. In the presence of 6.7 103 M dichloropheny 1.1,1-dimethylureaor 3 104 M o-phenanthroline, non-cyclic photophosphorylationwith 2 104 M DCPI plus 6.7 103 M ascorbateas the electron donor system decreased to about half that ofthe control, and the remaining activities were hardly affectedeven at higher concentrations of both inhibitors. The P/2eratios of non-cyclic photophosphorylation in the absence andpresence of ophenanthroline were 0.74 and 0.48, respectively.
1Present address: Department of Biology, University of California,San Diego, La Jolla, California 92037, U. S. A. 相似文献
5.
Low temperature tolerance was investigated in the imbibed seedof 15 seed lots compnsmg seven cultivars of Lactuca sativa L.During rapid cooling (20 °C h1) some seeds of allseed lots survived to 16 °C but none to 20°C. The majority of seed lots retained over 50 per centviability above 14 °C due to isolation of the embryofrom external ice by the endosperm, and subsequent embryo super-cooling.Certain seed lots, including all three seed lots of cv. TomThumb, showed high mortality at temperatures above 10°C. Correlation of mortality with the formation of externalice suggested that the endosperm is not an effective nucleationbarrier in these seed lots. Survival to 20 °C was increased at slower coolingrates (6 to 1 °C h1) due to freeze desiccation ofthe embryo, but seed lots varied considerably in their toleranceof specific cooling rates. A model to explain this variationwas developed incorporatmg (1) seed lot super-cooling limittemperature, (2) the rate at which freeze dehydration of thesupercooled embryo took place, (3) the moisture content at whichnucleation (at 20 °C) was no longer certain and (4)the.initial equilibrium moisture content of the fully imbibedseed. Factors (1), (2) and (3) were found to be relatively constant,but low (or artificially reduced) seed moisture content wasclosely correlated with high survival at natural cooling rates.Seed size fractions of similar moisture content from a singlecultivar showed that more small seeds survive cooling at 3 °Ch1 to 20 °C than larger seed. Seed with pierced endosperms or ineffective nucleation barrierswere capable of surviving to at least 10 °C if cooledslowly (1 °C h1) but were killed by rapid (20 °Ch1) cooling. Lactuca sativa L, lettuce, seed germination freezing tolerance, super-cooling 相似文献
6.
Density and distribution of bacterioplankton and planktonic ciliates in the Bering Sea and North Pacific 总被引:3,自引:0,他引:3
The total number of planktonic bacteria in the upper mixed layerof the Bering Sea during the late spring-early summer periodranged between 1 and {small tilde}4 x 106 ml1 (biomass1040mg C m3). In the northern Pacific, along 47526N,the corresponding characteristics of the bacterioplankton densityin the upper mixed water layer were: total number 12x 106 cells ml1 and biomass 1546mg C m3Below the thermocline at 50100 m, the density of bacterioplanktonrapidly decreased. At 300 m depth, it stabilized at 0.10.2x 106 cells ml1. The integrated biomass of bacterioplanktonin the open Bering Sea ranged between 1.2 and 3.6 g C m2(wet biomass 618 g m2) Its production per dayvaried from 2 to 23 mg C m3 days1 in the upper0100 m. The numerical abundance of planktonic ciliatesin this layer was estimated to be from 3 to l0 x 103 cells l1,and in the northern Pacific from 0.4 to 4.5 x 103 l2.Their populations were dominated by naked forms of Strombidium,Strombilidium and Tontonia. In some shelf areas, up to 40% ofthe total ciliate population was represented by the symbioticciliate Mesodinium rubrum. The data on the integrated biomassof basic groups of planktonic microheterotrophs are also presented,and their importance in the trophic relationships in pelagiccommunities of subarctic seas is discussed. 相似文献
7.
The effects of a number of growth-promoting and growth-inhibitingsubstances, including two fungal toxins, were studied on theextension of segments of etiolated tomato seedling hypocotyls.The bioassay was sensitive to small quantities of NaF, coumarinand 2, 4-DNP and inhibition was observed at all concentrations.2, 4-DNP or Iodoacetate stimulated growth at concentrationsbetween 1? 104 and 5 ? 106M. or 1 ? 106and 1 ? 107M. respectively. Inhibitor experiments inbuffered nutrient solution were approximately 10 per cent. moresensitive than those in deionized water. By means of paper partition chromatography small quantitiesof two fungal toxins, fusaric and alternaric acid were chromatographedand bioassayed. The effect of fussric acid (5, n-butyI picolinicacid) on hypocoty1 growth was detected at concentrations aslow as 1 ? 105M. Experiments with recongnized growth-promoting substances showedthat Kinetin inhibited growth at concentrations up to 1 ?108M.in both light and dark. IAA inhibited growth up to 1 ? 106M.At 1 ? 107 and 1 ? 108 only small increases occurredwith IAA and the effect of light was negligible. Gibberellicacid (GA2)stimulated growth at concentrations from 103to 107M. and significant increases up to 17 per cent.were recorded in the light. Since the light induced inhibitionwas only partly restored, the existence of some other naturallight sensitive growth substance is suggested. The value ofthe bioassay as a method for estimating natural growth-inhibitingand growth-promoting substances is discussed. 相似文献
8.
Zooplankton fecal pellet fluxes and vertical transport of particulate organic material in the pelagic environment 总被引:3,自引:0,他引:3
Fecal pellet fluxes were determined using a series of multireplicatetraps set at 35, 65, 150, 500, 750 and 1500 m in the northeastPacific. Fecal pellets appear to be important contributors to total carbonfluxes. In near-surface waters (35150 m), pellet fluxesranged from 23 x 105 pellets m2 day1. Minimumpellet fluxes were observed at 500m({small tilde}0.4x 105 pelletsm2day1). In contrast, the 1500 m pellet flux valueincreased to approximately 0.8 x 105 pellets m2 day1relative to the 500 m depth, and is probably the result of insitu repackaging. Analyses of pellet content suggest multiplesources of "large" particle input throughout the water column.The implications of this phenomenon are discussed in terms ofthe detrital rain and ladder of migration theories. 相似文献
9.
The electron carrier effective in nitrite reduction in proplastidsof cultured tobacco cells has been purified by DEAE-celluloseand Sephadex G-100 chromatography. Its electron carrying activityin the nitrite reduction system with dithionite showed that355 nmol NO2 reduced mg1 protein min1.The electron carrier had absorption maxima at 419, 459 and 469nm, and the absorbance peak at 419 nm was decreased 56% on reduction.The reduced form of the electron carrier showed an electronparamagnetic resonance signal with g=1.93. Thus, this electroncarrier is a kind of ferredoxin. It did not, however, show electroncarrying activity in the NADP-photoreduction system of chloroplasts.Its molecular weight was calculated as 19,500 by Sephadex G-100chromatography.
1Present address: Second Department of Anatomy, Fukushima MedicalCollege, Sugitsuma-cho, Fukushima 960, Japan. (Received April 11, 1983; Accepted February 6, 1984) 相似文献
10.
The current patterns around zygotic embryos of the oil palmembryo (Elaeis guineensis Jacq.) were investigated. Ionic currentsaround the embryo were measured at different stages in its developmentusing a two-dimensional vibrating probe system. The averagecurrent density was found to be in the order of 1µAcm2. In the early developmental stage, the current wasfound entering the cotyledon and leaving the radicle. Both themagnitude and direction of this current changed when embryosat different developmental stages were observed. The currentswere found to enter the region in the process of differentiationor elongation, and in some cases this could be the reverse ofthe current direction in the preceding stage. Within one ofthe stages of the embryos, current density was correlated withthe rate of elongation. A very large inward current (up to 20µAcm2) was also detected at the point where the shoot wasbreaking through the surface. This was probably caused by theso-called injury current. Key words: Ionic currents, vibrating probe, oil palm embryo, E. guineensis, injury current 相似文献
11.
Effects of respiratory inhibitors on frond and flower productionin light culture of a long-day duckweed, Lemna gibba G 3, wereinvestigated. The inhibitors examined could be divided into3 groups based on their specific actions: (A) 2,4-Dinitrophenol(106M), arsenate (104M), malonate (102M),o-phenanthroline (106M), ,'-dipyridyl (105M) andazide (106M) inhibited flower production by suppressingthe rate of flower production without affecting the inductionperiod. Frond production, however, was promoted by these reagents.Effective time of application came one day after the end ofthe induction period. (B) Iodoacetate (106M) and fluoride(104M) inhibited both flower production and, less significantly,frond production. Reduced rate of flower production was responsiblefor the inhibition of flowering. Effective time of applicationpreceded by one day that of A group inhibitors. (C) Salicylaldoxime(106M), diethyldithiocarbamate (106M) and 8-hydroxyquinoline(107M) enhanced flower production by reducing the lengthof the induction period, and simultaneously slightly inhibitedfrond production. Effective time of application was the latterhalf of the induction period. The implications of these findingsare discussed with special reference to the component processesinvolved in photoperiodic induction of flowering in duckweed. (Received March 27, 1969; ) 相似文献
12.
Nitrate reductase (NR) was assayed in vivo in cassava (Manihotesculenta Crantz). Activity in the leaves ranged from 0 to 2.51µmole of NO3 reduced g1 h1, withno activity in the younger leaves (leaf 1 on top). NR activitywas localized in the sides and toward the tip of the lobes ofthe leaf. (Received December 10, 1985; Accepted April 8, 1986) 相似文献
13.
In this paper we report measurements concerning the conductivityof water and ions and the interaction between the two in excisedpieces of xylem of red maple stems under various conditions.We have also demonstrated that it is possible to detect theflow of solutions through the stems of maple by measuring thedegree of interaction between the flow of water and ions. Inthis technique we apply voltage pulses of ±V volts acrossa length of stem and detect the unequal current pulses resultingfrom the greater frictional drag when current (which is carriedprimarily by cations) is flowing against the water stream thanwhen flowing with the water stream. The hydraulic conductivityof recent maple sapwood ranges from 30 to 90 cm3 s1 cm2(J cm3)1 cm; in 2 mM KCl the electrical conductivityis roughly 3 x 104 mho cm1 and the electro-kineticcross coefficient is roughly 4x105 A cm2 (J cm3)1cm. 相似文献
14.
A cell extract from acetate-grown Trichosporon cutaneum WY2-2inhibited auto-oxidation of phenolics, especially that of hydroxyquinol.It prevented auto-oxidation of hydroxyquinol without directinteraction with hydroxyquinol. Bovine erythrocyte superoxidedismutase had similar characteristics as the cell extract, andthe elution patterns of superoxide dismutase activity and ofthe inhibitory activity to hydroxyquinol auto-oxidation froma Sephadex G-150 column coincided. These results indicate thatthe inhibitory activity in the cell extract is mainly due tosuperoxide dismutase. High activity of superoxide dismutase(2030 unit/mg protein) and its isozyme profiles suggestan intimate relation between the regulation of superoxide dismutaseand catabolism of phenolics via hydroxyquinol.
1Present address: Biological Institute, Faculty of Science,Nagoya University, Nagoya 464, Japan.
2Present address: Shin Nihon Chemical Co. Ltd., 19-10, Showa-cho,Anjoh, Aichi 446, Japan. (Received November 15, 1985; Accepted July 3, 1986) 相似文献
15.
Suzuki Masaharu; Koide Yasuhiro; Hattori Tsukaho; Nakamura Kenzo; Asahi Tadashi 《Plant & cell physiology》1995,36(6):1067-1074
Deletion analysis of the promoter region of a gene for catalase,cat2, from castor bean (Ricinus communis) was performed to identifythe cis-regulatory elements responsible for the expression ofa rß-glucuronidase (GUS) fusion gene during seed formationand postembryonic development in transgenic tobacco. The analysisshowed that multiple cis-elements contribute to the activityof the cat2 promoter during seed formation and postembryonicdevelopment. The 5'-upstream regions from 1,241 to 816bp, from 720 to 682 bp, and from 632 to535 bp, relative to the site of initiation of translationof cat2, contributed positively to the activity of the cat2promoter during both stages. By contrast, the region from 816to 720 bp had a negative effect at both stages. The regionfrom 682 to 632 bp contributed positively to theactivity during seed formation but negatively during postembyonicdevelopment. Histochemical analysis revealed that the multiplecis-elements determined not only the level of expression ofthe chimeric gene but also the tissue-specificity of such expression.For example, the region from 1,241 to 816 bp allowedexpression of the chimeric gene in the axis of the embryo ofthe dry seed, as well as in the cortex of the middle part ofthe hypocotyl and at the base of epicotyl in the young seedling.
1Present address: Department of Plant Molecular and Cell Biology,University of Florida, Gainesville, Florida 32611-0511, U.S.A.
2Present address: Center for Molecular Biology and Genetics,Mie University, 1515 Kamihama, Tsu, Mie, 519 Japan
3Present address: Faculty of Biotechnology, Fukui PrefecturalUniversity, 4-1-1 Kenjojima, Matsuoka-cho, Yoshida-gun, Fukui,910-11 Japan 相似文献
16.
The purpose of the investigation is the determination of thevolumes and numbers of cells of the meristematic dome and ofeach of the first 7 primordia and internodes at the apex ofthe shoot of Lupinui albus. This system occupies a zone whichis about 0·4 mm. in length. Techniques are describedfor dissecting the region in which the observations are made,for determining the numbers of cells and the volumes of theseveral fragments. From the number of cells and the volume ofeach fragment an average cell volume it calculated. It is shown that in the midphase of the plastochron the domecontains 3,500 cells and has a volume of 1·6 x103mm.3,the first primordium contains 1,630 cells and has a volume of0·38 x103 mm.3, and the first intemode containsabout 700 cells and has a volume of about 1·4 x103mm3The number of cells and the volume of the primordium increaseexponentially with increasing plastochron age, and the seventhprimordium contains 26,000 cells and has a volume of 20·9x 103mm3 The seventh intemode contains about 5,000 cellsand has a volume of 8·6x103mm3 The average cell volume in the dome is 4·7 x 107mm.3in the first primorndium it is 2·3 x 107mm.3 andin the first internode it is 20·9x 107mm.3 Inthe seventh primordium the average cell volume increases to7·9 x 107mm.3 In the internodes there is little,if. any, change in cell volume from the first to the seventhof the series. The significance of these changes is discussed. 相似文献
17.
The Initial Uptake of Ions by Barley Roots: II. APPLICATION OF MEASUREMENTS ON SORPTION OF ANIONS TO ELUCIDATE THE STRUCTURE OF THE FREE SPACE 总被引:1,自引:0,他引:1
In previous experiments on excised barley roots, results werepresented showing the effect of varying the concentration ofthe uptake solution on the amount of anion which could subsequentlybe extracted in water. It was concluded that the system couldbe more satisfactorily analysed by means of the GoüyChapmanelectrical double-layer theory than by the Donnan theory. Onthe basis that ions diffuse into a system of negatively chargedpores within the root, the relationship between the quantityof water-extractable anion and its concentration in the uptakesolution has been examined in the light of the electrical double-layertheory. For potassium iodide and sulphate the experimental resultsconformed reasonably well with a structural model for the FreeSpace of parallel, charged surfaces separated by a mean distanceof about 200 A. The internal surface area of the free spacewas estimated as 2x106 cm2/g dry weight. The uptake of iodidefrom calcium iodide was somewhat greater than that predictedby the theory; this may be ascribed to interaction between theanions and divalent cations within the double layer. 相似文献
18.
Perez Valesca; Fernandez Emilio; Maranon Emilio; Serret Pablo; Garcia-Soto Carlos 《Journal of plankton research》2005,27(2):189-197
The seasonal variability of phytoplankton in the EquatorialAtlantic was analysed using Sea-viewing Wide Field-of-view Sensor(SeaWiFS)-derived chlorophyll a (Chl a) concentration data from1998 to 2001, together with in situ Chl a and primary productiondata obtained during seven cruises carried out between 1995and 2000. Monthly averaged SeaWiFS Chl a distributions werein agreement with previous observations in the Equatorial Atlantic,showing marked differences between 10° W in the EasternTropical Atlantic (ETRA) and 25° W in the Western TropicalAtlantic (WTRA) provinces (Longhurst et al. 1995. J. PlanktonRes., 17, 12451271). The seasonal cycle of SeaWiFS-derivedChl a concentration calculated for 010° S, 020°W (ETRA) is consistent with in situ Chl a measurements, withvalues ranging from 0.16 mg m3, from February to April,to 0.52 mg m3 in August. Lower variability was observedin 10° N10° S, 2030° W (WTRA) whereminimum and maximum concentrations occurred in April (0.15 mgm3) and in August (0.24 mg m3), respectively.A significant empirical relationship between depth-integratedprimary production and in situ measured sea surface Chl a wasfound for ETRA, allowing us to estimate the seasonal cycle ofdepth-integrated primary production from SeaWiFS-derived Chla. As for Chl a, this model was verified in a small area ofthe Eastern Equatorial Atlantic (010° S, 020°W), although in this instance it was not completely able todescribe the magnitude and temporal variability of in situ primaryproduction measurements. The annual euphotic depth-integratedprimary production rate estimated for ETRA by our empiricalmodel was 1.4 Gt C year1, which represents 16% of theopen ocean primary production estimated for the whole AtlanticOcean. 相似文献
19.
The specific respiration rates of nodulated root systems, ofnodules and of roots were determined during active nitrogenfixation in soya bean, navy bean, pea, lucerne, red clover andwhite clover, by measurements on whole plants before and afterthe removal of nodule populations. Similar measurements weremade on comparable populations of the six legumes, lacking nodulesbut receiving abundant nitrate-nitrogen, to determine the specificrespiration of their roots. All plants were grown in a controlled-environmentclimate which fostered rapid growth. The specific respiration rates of nodulated root systems ofthe three grain and three forage legumes during a 714-dayperiod of vegetative growth varied between 10 and 17 mg CO2g1 (dry weight) h1. This mean value consistedof two components: a specific root respiration rate of 69mg CO2 g1 h1 and a specific nodule respirationrate of 2246 mg CO2 g1 h1. Nodule respirationaccounted for 4270 per cent of nodulated root respiration;nodule weight accounted for 1240 per cent of nodulatedroot weight. The specific respiration rates of roots lackingnodules and utilizing nitrate nitrogen were generally 2030per cent greater than the equivalent rates of roots from nodulatedplants. The measured respiratory effluxes are discussed in thecontext of nitrogen nitrogen fixation, nitrate assimilation. Glycine max, Phaseolus vulgaris, Pisum sativum, Medicago sativa, Trifolium pratense, Trifolium repens, soya bean, navy bean, pea, lucerne, red clover, white clover, nodule respiration, root respiration, fixation, nitrate assimilation 相似文献
20.
Seedlings of Zea mays L. (John Innes hybrid) were grown withroots divided between two containers such that part of the rootsystem could reduce the water potential of the soil in its immediatevicinity while the rest of the root system was well suppliedwith water. When compared to plants rooted in two pots of moistsoil, drying of part of the root system resulted in partialclosure of stomata, even though leaf water potential, turgorand abscisic acid (ABA) content remained unaffected. When leafpieces were removed from the two groups of plants and incubatedunder conditions favourable for stomatal opening, stomata ofthe half-watered plants still showed restrictedapertures. Incubation in kinetin (10 mmol m3) or zeatin(100 mmol m3) reversed the closure of stomata stimulatedby soil drying. These results suggest that a continuous supplyof cytokinin from roots may be necessary to sustain maximalstomatal opening and an interruption of this supply due to soildrying may act as an indicator of inhibited root activity, resultingin restricted stomatal opening and thereby restricted wateruse. Key words: Zea mays L., Soil drying, Stomata, Roots 相似文献