The Presence of Lipids But Absence of Tannins in Elodea Idioblasts

The presence of tannins in the idioblasts of Elodea densa is conclusively disproved. Ten reagents for histochemical detection of tannin (K₂Cr₂O₇, K₃Fe(CN)₆, FeCl₃, (NH₄)₂MO₄, Nessler's reagent, Fehling's reagent, methylene blue, gelatin, iodine-KI and lead acetate) gave negative tests in Elodea idioblasts. Two reagents (1% aqueous caffeine and a saturated solution of Ca(OH)₂) gave apparently positive reactions that could be explained by the presence of lipids. Positive tests for lipids were obtained by direct microscopic examination of the removal of lipid materials from freeze-dried leaves, using a 1:1 ether-alcohol mixture. The lipid material was not removed when acetone was substituted for ether-alcohol. A lipoprotein complex was demonstrated by using Serra's method for masked lipids.     

Nitrogen use efficiency by a slow-growing species as affected by CO2 levels, root temperature, N source and availability

This study examines the importance of N source and concentration on plant response to distinct CO₂ concentrations and root temperatures. The experimental design of this work was a factorial combination of: CO₂ concentration, nitrogen concentration, nitrogen source and root temperature. Carob (Ceratonia siliqua L.) was assessed as a potential model of a slow growing Mediterranean species.

The results showed that: 1) biomass increment under high CO₂ varied between 13 and 100 percnt; in relation to plants grown under the same conditions but at ambient CO₂ concentrations, depending on the root temperature and nitrogen source; 2) nitrate-fed plants attained a larger increase in biomass production compared to ammonium-fed ones. This performance seems to be linked to the co-ordinated regulation of the activities of glutamine synthetase and sucrose phosphate synthase. The variations in the magnitude and nature of growth responses to elevated CO₂ observed resulted in substantial changes in the chemical composition of the plant material and consequently in plant nitrogen use efficiency.

Although performed with seedlings and under controlled conditions, this work emphasizes the importance of the nitrogen source used by the plants, a factor rarely taken into consideration when forecasting plant responses to global changes. Particularly, the results presented here, highlight the potential for uncoupling biomass accumulation from increment of air CO₂ concentration and show that more than nitrogen availability N source may offset positive plant growth responses under elevated CO₂ and root temperature.     

Photoperiodic control of endogenous gibberellins in seedlings of Salix pentandra

In the temperate-zone woody species Salix pentandra elongation growth is regulated by the photoperiod. Long days sustain active growth, whereas short days induce cessation of apical growth, which is a prerequisite for winter hardening. It is shown that this is correlated to quantitative changes in levels of endogenous GA₁₉ GA₂₀, and GA₁. Within two short days the amount of the active GA₁ and its immediate precursor GA₂₀, decreased markedly in young leaves us well as in stem tissue. Also, the amount of GA¹⁹, declined, but the decrease was delayed relative to that of GA₁ and GA₂₀. The ability of S. pentandra seedlings to respond to exogenous GA₁₉, decreased with increasing numbers of short days. Observations that support the hypothesis that the level of GA₁ in S. pentandra is regulated by the photoperiod in a quantitative mode with conversion of GA₁₉, to GA₂₀, being one target for control.
Different distribution of GAs in various plant parts was observed. The level of GA was higher in young leaves than in other plant parts, and the amount of GA₁₉ was 5–10 times higher in stem tissue than in leaves and roots. The ratios of GA₈ to GA¹ and GA₂₀, were higher in roots as compared with other parts, as rods contained very low levels of GA₁ and GA₂₀, but amounts of GA₂₀ comparable with other parts.     

Influence of leaf chemistry of Lotus corniculatus (Fabaceae) on larval development of Polyommatus icarus (Lepidoptera, Lycaenidae): effects of elevated CO2 and plant genotype

1. Four Lotus corniculatus genotypes differing in cyanoglycoside and condensed tannin concentrations were grown in either low (350 ppm) or high (700 ppm) atmospheric CO₂ environments. Larval performance, consumption and conversion efficiency of Polyommatus icarus feeding on this plant material were measured.
2. Plants grown under elevated CO₂ contained less cyanoglycosides, more condensed tannins and more starch than control plants. However, water concentration, nitrogen and protein as well as nitrogen concentration in relation to carbon concentration did not differ between CO₂ treatments.
3. The four genotypes differed significantly in condensed tannins, cyanoglucoside, leaf water and leaf nitrogen but no genotype–CO₂ interaction was detected, except for total phenolics and condensed tannins in which two plant genotypes showed stronger increases under elevated CO₂ than the other two.
4. Larvae of P . icarus consumed more plant material and used and converted it more efficiently from plants grown at high atmospheric CO₂.
5. Larvae developed significantly faster and were significantly heavier when fed plant material grown under elevated CO₂. The observed difference in mass disappeared in the pupal and adult stages. However, lipid concentration of adults from the elevated CO₂ treatment was marginally significantly higher than of controls.
6. It is concluded that the higher carbohydrate concentration of L . corniculatus plants grown at elevated CO₂ renders leaves more suitable and better digestible to P . icarus . Furthermore, differences in allelochemicals might influence the palatability of L . corniculatus leaves for this specialist on Fabaceae.     

Improving the Technic of the Feulgen Stain

A study has been made of the Feulgen stain, in which the staining fluid is a decolorized basic fuchsin. Particular attention has been given to the variation in behavior of different fuchsin samples, the reagent to be employed in decolorizing the dye, the acidity of solutions, and the value of several counter-stains. A modified procedure is suggested, the details of which are given in the paper. The principle modifications of earlier procedures which are recommended are as follows: the use of a specially purified pararosanilin as a dye; the employment of K₂S₂O₅ instead of NaHSO₃ as a decolorizing agent; and counterstaining with fast green in the case of plant tissue or with orange G for animal material.     

Effects of age, supra-ambient oxygen and repeated assays on acetylene reduction and root respiration in pea

An open flow-through gas system was used to investigate the effect of plant age on nitrogenase activity in relation to root respiration (measured as CO₂ release) and supra-ambient O₂ levels in 24- to 51-day-old, nodulated Pisum sativum L. cv. Bodil. The effect of assaying plants repeatedly was also studied. The respiratory efficiency of nitrogenase [mol CO₂ (mol C₂H₄)⁻¹] and the relative decline in nitrogenase (EC 1.7.99.2) activity in response to introduction of C₂H₂ in the gas stream were unaffected by plant age. In contrast, the nitrogenase-linked respiration as a proportion of total root respiration increased with time. Accordingly, the specific respiration linked-to growth and maintenace of the noduled root system decreased with time. C₂H₂ reduction and root respiration were increased by supra-ambient O₂ levels, but the tolerance to high O₂ concentrations seemed to decrease with plant age. Repeated C₂H₂ assays on the same plants decreased their rate of growth and N accumulation: in addition, nitrogenase activity and root respiration were somewhat negatively affected. The results indicate that results from experiments with plants of different ages cannot always be directly compared, and that repeated C₂H₂ assays on the same plants should be applied with caution in physiological work.     

Effects of temperature, ultraviolet radiation and pectin methyl esterase on aerobic methane release from plant material

This study examines the effects of different irradiance types on aerobic methane (CH₄) efflux rates from terrestrial plant material. Furthermore, the role of the enzyme pectin methyl esterase (PME) on CH₄ efflux potential was also examined. Different types of plant tissue and purified pectin were incubated in glass vials with different combinations of irradiation and/or temperature. Purified dry pectin was incubated in solution, and with or without PME. Before and after incubation, the concentration of CH₄ was measured with a gas chromatograph. Rates of CH₄ emission were found to depend exponentially on temperature and linearly on UV-B irradiance. UV-B had a greater stimulating effect than UV-A, while visible light had no effect on emission rates. PME was found to substantially reduce the potential for aerobic CH₄ emissions upon demethylation of pectin.     

供氮水平对矮化苹果15N-尿素吸收、利用、损失及产量和品质的影响

以7年生烟富3/M26/平邑甜茶为试材,采用¹⁵N同位素示踪技术,研究不同供氮水平[低氮(100 kg N·hm^-2,N₁₀₀)、中氮(200 kg N·hm^-2,N₂₀₀)和高氮(300 kg N·hm^-2,N₃₀₀)]对烟富3/M26/平邑甜茶¹⁵N-尿素吸收、利用、损失及产量和品质的影响.结果表明: 不同供氮水平植株的生长状况及氮素吸收、利用和损失特性差异显著.N₂₀₀处理植株叶绿素含量(SPAD)、光合速率(P_n)、叶片全氮含量和生物量显著高于N₁₀₀和N₃₀₀处理,植株根冠比也显著增加.不同供氮水平下植株各器官对氮的吸收能力(Ndff值)存在显著差异,各测定时期果实(花)、叶片、一年生枝、多年生枝和中心干的Ndff值均为N₁₀₀>N₂₀₀＞N₃₀₀;而根的Ndff值在盛花期和春梢缓长期为N₁₀₀ >N₂₀₀＞N₃₀₀,在秋梢生长期、果实膨大期和果实成熟期为N₂₀₀ >N₁₀₀＞N₃₀₀.在果实成熟期,N₂₀₀处理¹⁵N肥料利用率为23.6%,显著高于N₁₀₀(16.3%)和N₃₀₀处理(14.4%),而¹⁵N损失率为56.4%,显著低于N₁₀₀(60.6%)和N₃₀₀处理(66.1%).不同供氮水平植株的平均单果质量、单株产量、可溶性固形物、硬度、可溶性糖、可滴定酸、糖酸比均存在显著差异,且均以N₂₀₀处理最高,其次是N₃₀₀处理,N₁₀₀处理最低.     

Detection and identification of gibberellins in Sitka spruce (Picea sitchensis) of different ages and coning ability by bioassay, radioimmunoassay and gas chromatography – mass spectrometry

Gibberellins Al (GA₁), GA₃, GA₄, GA₉, and after enzymatic hydrolysis of GA-conjugate-like fractions, GA₉ and GA₁₅, were identified in shoots of Sitka spruce [ Picea sitchensis (Bong.) Carr.] of different ages by combined gas chromatography-mass spectrometry (GC-MS). The purification and separation of the GAs involved the use of reverse phase and normal phase high performance liquid chromatography (HPLC). The Tan-ginbozu dwarf rice bioassay and binding to antibodies raised against GA₁, GA₄ and GA₉ were used for detection of GA-like substances. The qualitative differences between the three ages of plant material were the presence of GA₃ and GA₁ in the 48-year-old material and the absence of detectable amounts of GA₄ in the same material. This indicates a difference in GA metabolism which may reflect the difference in ability to form reproductive buds.     

Changes in land plant function over the Phanerozoic: reconstructions based on the fossil record

Major fluctuations in the concentrations of atmospheric CO₂ and O₂, are predicted by historical long-term carbon and oxygen cycle models of atmospheric evolution and will have impacted directly on past climates, plant function and evolutionary processes. Here, palaeobotanical evidence is presented from the stomatal density record of fossil leaves spanning the past 400 Myr supporting the predicted changes in atsmopheric CO₂. Evidence from experiments on plants exposed to long-term high CO₂, environments and the newly-assembled fossil data indicate the potential for genetic modification of stomatal characters. The influence of the changes in fossil stomatal characteristics and atmospheric composition on the rates of leaf gas exchange over the course of land plant evolution has been investigated through modelling. Three contrasting eras of plain water economics emerge in the Devonian (high), Carboniferous (low) and from the Upper Jurassic to the present-day (high but declining). These patterns of change result from structural changes of the leaves and the impact of atmospheric CO₂, and O₂, concentrations on RuBisCo function and are consistent with the fossil evidence of sequential appearances of novel plant anatomical changes. The modelling approach is tested by comparing predicted leaf stable carbon isotope ratios with those measured on fossil plant and organic material. Viewed in a geological context, current and future increases in the concentration of atmospheric CO₂, might be considered as restoring plant function to that more typically experienced by plants over the majority of their evolutionary history.     

供氮水平对矮化苹果15N-尿素吸收、利用、损失及产量和品质的影响

以7年生烟富3/M26/平邑甜茶为试材,采用¹⁵N同位素示踪技术,研究不同供氮水平[低氮(100 kg N·hm^-2,N₁₀₀)、中氮(200 kg N·hm^-2,N₂₀₀)和高氮(300 kg N·hm^-2,N₃₀₀)]对烟富3/M26/平邑甜茶¹⁵N-尿素吸收、利用、损失及产量和品质的影响.结果表明: 不同供氮水平植株的生长状况及氮素吸收、利用和损失特性差异显著.N₂₀₀处理植株叶绿素含量(SPAD)、光合速率(P_n)、叶片全氮含量和生物量显著高于N₁₀₀和N₃₀₀处理,植株根冠比也显著增加.不同供氮水平下植株各器官对氮的吸收能力(Ndff值)存在显著差异,各测定时期果实(花)、叶片、一年生枝、多年生枝和中心干的Ndff值均为N₁₀₀>N₂₀₀＞N₃₀₀;而根的Ndff值在盛花期和春梢缓长期为N₁₀₀ >N₂₀₀＞N₃₀₀,在秋梢生长期、果实膨大期和果实成熟期为N₂₀₀ >N₁₀₀＞N₃₀₀.在果实成熟期,N₂₀₀处理¹⁵N肥料利用率为23.6%,显著高于N₁₀₀(16.3%)和N₃₀₀处理(14.4%),而¹⁵N损失率为56.4%,显著低于N₁₀₀(60.6%)和N₃₀₀处理(66.1%).不同供氮水平植株的平均单果质量、单株产量、可溶性固形物、硬度、可溶性糖、可滴定酸、糖酸比均存在显著差异,且均以N₂₀₀处理最高,其次是N₃₀₀处理,N₁₀₀处理最低.     

Maillet's Oso4-ZnI2 Fixative and Alcian Blue Staining in the Study of Neurosecretion; Invertebrates

Maillet's OsO₄-ZnI₂ fixation staining can be combined with a subsequent counterstaining by Alcian blue or aldehyde fuchsin to demonstrate neurosecretory cells in addition to cytological details of the nerve tissue. This technic has been applied to various annelids: Eisenia foetida (Oligochaeta), Erpobdella octoculata (Achaeta) and Nereis diversicolor (Polychaeta). The material is fixed in a 1:4 mixture of 2% OsO₄ and 3% ZnI₂ for 15 nr, embedded in paraffin, sectioned at 5 μ and the sections alternatively mounted on two glass slides. One of these is oxidized by a solution of 0.3% KMnO₄ acidified by 0.6% H₂SO₄ and counterstained with 1% Alcian blue, pH 0.2, the other one is mounted in balsam. The two preparations may then be compared to locate the neurosecretory cells among the other neurons shown on a slide treated only by the OsO₄-ZnI₂. Secretory cells are not stained by Maillet's reagent; except for their Golgi bodies and their cellular and nuclear membranes. The zone of grains which is generally strongly stained by the Alcian blue takes a yellowish hue from the OsO₄-ZnI₂ fixation. This method could be successfully applied to the histological controls in regeneration experiments. In these last ones, we must simultaneously observe the regeneration of the nervous fibres and the possibility of intervention of neurosecretory elements.     

土壤水分对黄土区苹果园土壤-植物-大气连续体(SPAC)中水势梯度的影响

开展土壤-植物-大气连续体(SPAC)中水势变化的联动分析对于揭示植物水分状况对环境变化的响应机制有重要意义。在黄土高原苹果园对果树生长季大气水势(Ψ_air)、木质部水势(Ψ_stem)、土壤水势(Ψ_soil)进行连续监测与分析。结果表明: 苹果树在生长季的日平均Ψ_stem为-0.57 MPa,在-0.24～-2.0 MPa间变化。苹果树SPAC连续体中水势梯度(Ψ_soilΨ_stemΨ_air)平均为1∶9.8∶1155,其中植-土界面的水势梯度(Ψ_stemΨ_soil)与土壤体积含水率(VWC)间呈极显著的线性正相关关系,Ψ_stem与Ψ_soil间呈良好的线性关系,且相关性强于Ψ_stem与Ψ_air间的相关性。当Ψ_soil<-0.08 MPa(VWC=17%,约为田间持水量的0.56倍)时,Ψ_stem对Ψ_soil变化响应的敏感性明显降低,气-植界面的水势梯度(Ψ_airΨ_stem)与Ψ_soil间由无明显关系转变为紧密的线性相关关系(R²=0.93)。Ψ_air对Ψ_stem的驱动存在阈值效应,在Ψ_air降到-69 MPa前,Ψ_stem日变化幅度随Ψ_air增加而增加,之后呈下降趋势。土壤含水率降低引起苹果树水势、SPAC各界面上的水势梯度明显下降,且在土壤含水率降至约17%时存在阈值效应。研究结果为理解树木水分状况对土壤、大气干旱的响应机制提供了重要依据。     

Oriented responses of carrot fly larvae, Psila rosae, to plant odours, carbon dioxide and carrot root volatiles

ABSTRACT. The responses of carrot fly larvae, Psila rosae , to host plant volatiles were studied. Two criteria for an oriented response were used: one based on whether an individual reached within 1.5 cm of the odour source and one involving analysis of the track patterns of larvae within 3 cm of the odour source. All larval instars were attracted to both host and non-host plant material, though to a lesser degree by the latter; they were also attracted to CO₂, but not to N₂. A steam volatile fraction of carrot roots, and methyl eugenol, a volatile component of this fraction, also attracted the larvae, differentially at different concentrations. The possible roles of both CO₂ and the host-specific secondary plant volatiles in the host plant finding behaviour of soil inhabiting arthropods are discussed.     

High yield isolation of mesophyll protoplasts from wheat, barley and rye

Efficient procedures are described for high-yield isolation of mesophyll protoplasts from spring wheat ( Triticum aestivum L. cv. Glenlea), winter wheat ( Triticum aestivum L. cv. Frederick), barley ( Hordeum vulgare L. cv. Bruce) and rye ( Secale cereale L. cv. Puma). Factors such as plant age, composition of the incubation medium during isolation, purification procedures and culture medium affect protoplast yield, viability and metabolic competence, as measured by light-dependent CO₂ fixation. Optimal osmolarity of the isolation medium was equivalent to 1.8 times that measured in the leaves of all plant material used. The presence of 2 m M ascorbic acid in the preincubation and isolation medium increased the yield by 50% and conserved viability and metabolic competence. The protoplasts were stable for up to 48 h without loss of either viability or of original activity of CO₂ fixation, which was in the order of 100 μmol CO₂ (mg chl)⁻¹h⁻¹.
In our MC-56 liquid medium these protoplasts regenerated cell walls within 72 h and a few divided.     

Long-term effects of low levels of SO2 on bean plants (Phaseolus vulgaris). II. Immission-response effects on biomass production: quantity and quality

Bean plants ( Phaseolus vulgaris L. cv. Processer) were grown in water culture with separate air supply to roots for four to five weeks at five levels of SO₂ ranging from 10 μg m⁻³ to 950 μg m⁻³. At harvest the plant material was divided into six fractions: root, stem, fruit and leaves of three age groups.
Plants were mainly affected at and above approx. 250 μg m⁻³ SO₂. Fresh weight was reduced in mature and old leaves, and roots and fruit. Dry weight was also reduced in mature and old leaves, and roots and stem. A reduction was found in chlorophyll a and chlorophyll b in mature and old leaves, and also starch was reduced in the leaves. Sulfur content of leaves and fruit increased with exposure time and concentration, while Br, Ca, Cl, K, Mn, P and Zn increased at the highest SO₂ level only. Total (but not specific) peroxidase activity increased in all aerial fractions, i.e. soluble protein increased just like peroxidase activity. Seventeen studied amino acids all increased on the average by 38% in mature bean pods.
The observed effects may be parts of a reaction for survival and propagation of the plant, as fruit quality was not affected, indeed, it sometimes improved slightly. The latter observation is of commercial interest.     

The Nostoc-Gunnera symbiosis: carbon fixation and translocation

The in vitro specific activity of ribulose-1,5-bisphosphate carboxylase (Rubisco; EC 4. 1. 1. 39) and the dark and light in vivo CO₂ fixation activities were determined in the cyanobiont of Gunnera . Compared to the free-living isolate Nostoc PCC 9231, the in vitro Rubisco activity was high, while the in vivo CO₂ fixation was very low. Light did not significantly influence CO₂ fixation if the cyanobiont was left in the sliced Gunnera tissues, while a small light stimulation was found for CO₂ fixation of the freshly-isolated cyanobiont. The adjacent non-infected Gunnera tissue showed a very low CO₂ fixation. A rapid translocation of fixed ¹⁴CO₂ from leaves towards apical parts of the plant was apparent, in particular to the symbiotic tissue. The ¹⁴C label appeared mainly in soluble form in this tissue and was rapidly catabolised as shown by ¹⁴C chase experiments. Also, short-term experiments revealed that maximum ¹⁴C accumulation occurred in the symbiotic tissue showing the highest rates of nitrogen fixation (Söderbäck et al. 1990), about 10–15 mm from the plant apex. The data were taken to indicate that there is a modification in the photosynthetic light reaction of the cyanobiont and that the cyanobiont lives heterotrophically in the dark on photo-synthate rapidly delivered from nearby leaves of the host plant.     

Comparative Spectroscopy of Basic Fuchsin, Schiff Reagent, and a Formalin-Schiff Derivative in Relation to Dye Structure and Staining

Ultraviolet (UV) absorption (200-330 nm) for 0.5 mg/ml aqueous solutions of basic fuchsia unadjusted and those adjusted to pH 0, 1.5, 8.5, and 11 were determined as well as spectra in the visible range (400-675 nm) for solutions with pH 1.9, 2.8, 3.9, 4.7, 5.5, 5.9, 6.5, 7.5, 9.3, 10.4, and 11. The UV absorbance of degassed Schiff reagent containing 1 or 0.5 mg dye/ml, and that of this reagent adjusted to pH 1.5, 2.3, 3.1, 4.5, 6.0, 7.1, and 8.4 were obtained for comparison. The progressive reaction of formalin with degassed Schiff reagent, followed spectrometrically for 2.5 hr, required 2 hr to reach completion. The degassed Schiff reagent contained only traces of-SO₃H as judged from its minimal absorbance between 280 and 295 nm. The UV absorption of this reagent and basic fuchsin in 1 N HCl were found to be identical. The absorbance is that of basic fuchsin reduced by the addition of Cl^- or SO₃H^- to the central methane carbon and H to the amino groups, therefore the leuco structure of basic fuchsin so reduced shows the fomation-NH₃ groups. Infrared (IR) spectra of basic fuchsin, Schiff crystals, and a crystalline formalin-Schiff reaction product support these observations and indicate that the final colored product is a methylsulfonic acid derivative of basic fuchsin. Identical IR spectra were obtained for two types of crystals derived from Schiff reagents indicating that both are the same chemically, although only one became colored on exposure to air. When these crystals were redissolved and SO₂ added, a Schiff reagent of appropriate pH was produced. Since it is derived from a crystalline product, this type of reagent should be useful in histochemical studies     

Genotypic variation in coleus in the ability to accumulate abscisic acid in response to water deficit

Terry, P. H., Krizek, D. T. and Mirecki, R. M. 1988. Genotypic variation in coleus in the ability to accumulate abscisic acid in response to water deficit. - Physiol. Plant. 72: 441–449.
Abscisic acid (ABA) concentration and plant and soil water potentials were determined in leaves of three cultivars of Coleus blumei Benth. cvs. Marty, Buckley Supreme and PI354190, chosen for their differences in sensitivity to drought, SO₂ and/or chilling stress. Plants were subjected to 'gradual' soil moisture stress (SMS) for 0–6 days, during which time the soil dried out slowly and to more 'rapid' SMS for 0–9 days where the soil dried out at a faster rate. Plants were propagated from clonal stock in the greenhouse and transferred to the growth chamber, where they were maintained for 1 week prior to beginning water stress treatment. ABA concentration was determined as the methyl ester using a gas chromatography - electron capture detector method. Samples for ABA determinations were taken from the third pair of leaves from the apex at the same time each day (1430 h). Measurements of stomatal conductance (C₅) and leaf water potential (φ_l) were made on the fourth pair of leaves from the apex, using the same plants as those sampled for ABA. During the more rapid stress portion of the study soil matric potentials (φ_m) were monitored on a daily basis. Despite large cultivar differences in ABA concentration at 0–6 days, by 7–9 days these differences had largely disappeared. Except for drought-insensitive cv. Marty, there was generally little correlation between ABA levels and measurements of plant and soil water status at 7–9 days.     

Developmental expression and perturbation of arabinogalactan-proteins during seed germination and seedling growth in tomato

Arabinogalactan-proteins (AGPs) are a family of highly glycosylated hydroxyproline-rich glycoproteins present throughout the plant kingdom. A synthetic chemical reagent, ( β - d -Gal)₃ Yariv reagent, specifically binds AGPs and can be used for histochemical staining, isolating and probing the function of AGPs. Here, the role of AGPs in tomato ( Lycopersicon esculentum Mill. cv. UC82B) seed germination and seedling growth was examined by following expression of AGPs during these events and by treatment with ( β - d -Gal)₃ Yariv to perturb AGP function. AGP expression changed during germination and seedling development both quantitatively and qualitatively as revealed by analysis of total AGP content, crossed electrophoresis patterns, RNA blots using LeAGP-1 probe, and western blots with LeAGP-1, JIM13, and MAC207 antibodies. ( β - d -Gal)₃ Yariv treatment of seeds and developing seedlings did not affect percent seed germination, but markedly inhibited seedling growth in roots and to a lesser degree in shoots. Root growth inhibition encompassed reductions in overall root length, epidermal root cell elongation, root cell numbers and root hair formation. This growth inhibition was reversible following removal of ( β - d -Gal)₃ Yariv. In a related experiment, water uptake by tomato seedlings was greatly inhibited by ( β - d -Gal)₃ Yariv treatment. Based on these experiments, AGPs are clearly associated with tomato seedling development and likely to function in root growth, more specifically in cell elongation, cell proliferation, root hair formation and water uptake.