Introgressive hybridization between Plantago major L. taxa

Occurrence and direction of introgressive hybridization between Plantago major taxa were tested. Plantago major plants were collected from 10 Egyptian locations. Four populations of two European taxa were used for comparison. These are ecologically and geographically separated and were identified as the subspecies Plantago major ssp. major and Plantago major ssp. intermedia. In the Egyptian populations, most individuals fall within the variation range of P. major ssp. intermedia. Only one population, from Burg El-Arab, morphologically resembled clearly P. major ssp. major and showed some ISSR fragments that characterize pure populations of this taxon. All individuals of population 2 (Alexandria) and some individuals of populations 1, 3, 5, 6 and 10 (Alexandria, Aswan) morphologically corresponded to P. major ssp. intermedia. All individuals collected from Egypt had ISSR fragments characterizing both pure P. major ssp. major and pure P. major ssp. intermedia. Most of these individuals had a higher percentage of intermedia-type fragments than major-type fragments, suggesting that P. major ssp. intermedia in Egypt shows some introgression towards P. major ssp. major. The pure populations were distinct from each other, while the Egyptian populations were intermediate according to principal coordinate analysis (PCoA) of ISSR data. In the populations collected from Egypt, major and intermedia cannot be seen as separate species. The study suggests that the dominant taxa introgressed to the minority population(s). Taxon frequency may be a key component in determining the direction of introgression.     

Gibberellic acid affects growth and flowering of Philodendron‘Black Cardinal’

Changes in net photosynthetic rate (P_N), stomatal conductance (g_s), intercellular CO₂ concentrations (C_i), transpiration rate (E) and water use efficiency (WUE) were measured in Plantago major L. plants grown under sufficient soil water supply or under soil water stress conditions. The plants had high P_N in a wide range of soil water potential and temperature regimes. Soil water had little effect on P_N under ambient CO₂ concentrations, which was explained by a high carboxylation rate, but increased the dark respiration rate. Carboxylation activity at low C_i depended on RuBP regeneration, whereas at high C_i it depended on the phosphate regeneration rate. The g_s and E values were low in plants under stress as compared to the controls that resulted in an increase of WUE. The results obtained show that Plantago major plants have different ways of adaptation to soil water deficit conditions.     

Lipid Composition of the Roots of Plantago Species: Response to Alteration of the Level of Mineral Nutrition and Ecological Significance

In a study of the adaptation of Plantago species to their specific environment the lipid composition of the roots of several species: Plantago major L. ssp. major, Plantago major L. ssp. pleiosperma Pilger, Plantago lanceolata L., Plantago media L., Plantago maritima L., Plantago coronopus L. was studied as well as the effect of the nutritional regime. Upon exposure to low-salt conditions Plantago major L. ssp. major L. and Plantago maritima L. maintained the level of free sterols in the roots, despite a depressed level of total sterols, and the root lipids were more saturated than under high-salt conditions. Both factors may reduce nutrient leakage from the roots to the low-salt condition. Upon exposure to low-salt conditions, all Plantago species showed a decreased level of galactolipid (exception: Plantago coronopus) and a decreased level of sitosterol (exception: Plantago maritima); the latter being compensated by an elevated level of cholesterol + tocopherol in Plantago major ssp. pleiosperma, Plantago lanceolata and Plantago media. Plantago coronopus was the only species which under low-salt conditions showed an increased level of free sterols, among which cholesterol was the most important; thus indicating a high degree of regulation of membrane permeability under alternating nutritional conditions. The level of sulfolipid was kept constant in all Plantago species, with the highest level observed in Plantago maritima. The role which various lipids may play in maintenance of membrane integrity under alternating nutritional conditions is discussed.     

Inhibition and stimulation of root respiration in pisum and plantago by hydroxamate : its consequences for the assessment of alternative path activity

The contribution of the alternative pathway in root respiration of Pisum sativum L. cv Rondo, Plantago lanceolata L., and Plantago major L. ssp major was determined by titration with salicylhydroxamate (SHAM) in the absence and presence of cyanide. SHAM completely inhibited the cyanide-resistant component of root respiration at 5 to 10 millimolar with an apparent K_i of 600 micromolar. In contrast, SHAM enhanced pea root respiration by 30% at most, at concentrations below 15 millimolar. An unknown oxidase appeared to be responsible for this stimulation. Its maximum activity in the presence of low SHAM concentrations (1-5 millimolar) was 40% of control respiration rate in pea roots, since 25 millimolar SHAM resulted in 10% inhibition. In plantain roots, the maximum activity was found to be 15%. This hydroxamate-activated oxidase was distinct from the cytochrome path by its resistance to antimycin. The results of titrations with cyanide and antimycin indicated that high SHAM concentrations (up to 25 millimolar) block the hydroxamate-activated oxidase, but do not affect the cytochrome path and, therefore, are a reliable tool for estimating the activity of the alternative path in vivo. A considerable fraction of root respiration was mediated by the alternative path in plantain (45%) and pea (15%), in the latter because of the saturation of the cytochrome path.     

Hybridizations and genetic relationships among Lindernia species (Scrophulariaceae): L. procumbens and two subspecies of L. dubia

Lindernia procumbens and L. dubia are common annual weeds in flooded rice fields of Japan. Two subspecies of L. dubia, subsp. major and subsp. dubia, are usually recognized in Japan but they are both regarded as synonyms of L. dubia elsewhere. In a cluster analysis based on AFLP, most L. dubia subsp. major formed a separate cluster from L. dubia subsp. dubia although 11% of haplotypes classified using AFLP were not coincident with classification using the shape of leaf bases, which is the commonly used identification trait. Artificial F₁ plants between L. procumbens and L. dubia subsp. major, and between L. procumbens and L. dubia subsp. dubia did not produce seed. Forty percent of capsules produced by F₁ plants from these two subspecies were slimmer and 80% pollen were sterile in slimmer capsules. However, seed number of most F₁ capsules was not different from that of self-fertilized plants, suggesting that there was no complete reproductive isolation between the subspecies. Natural hybridization of these subspecies may have occurred but we are not aware of it because F₁ plants are rare and F₂ plants are indistinguishable from these subspecies.     

Kinetics of nitrate uptake by different species from nutrient-rich and nutrient-poor habitats as affected by the nutrient supply

The species Urtica dioica L., Plantago major ssp. major L., Plantago lanceolata L., Hypochaeris radicata L. ssp. radicata and Hypochaeris radicata ssp. ericetorum Van Soest were grown under high and low nutrient conditions (1/4 Hoagland and 2% of 1/4 Hoagland further called the 100% and 2% treatment, containing 3.75 mM NO^-₃ and 0.075 mM NO^-₃, respectively). After a certain period half of the plants were transferred from low to high or high to low nutrients, yielding the 100%/2% and the 2%/100% treatments. The kinetics of nitrate uptake in the range of system I of the five species grown under the different nutrient conditions were measured during a three week experimental period. The nitrate uptake of all the species showed the characteristic features of Michaelis-Menten kinetics. Under low nutrient conditions the apparent V_max of U. dioica expressed per g dry root was lower than under high nutrient conditions. For H. radicata ssp. radicata and for H. radicata ssp. ericetorum the reverse was found. The V_max values of P. major ssp. major were almost the same for the two treatments. The apparent V_max in young plants of P. lanceolata was higher in the 100% treatment than in 2%; whereas the reverse was found in mature plants. The results are explained in relation to the relative growth rate, the shoot to root ratio and the natural environment of the species. The apparent K_m values were not influenced by the different treatments. Differences in K_m between the species, if any, were very small. It is suggested that the V_max is a more important parameter for the distribution of plant species in the field than the K_m. The rate of nitrogen accumulation was calculated from growth data and the contents of nitrate and reduced nitrogen. It is concluded that the V_max of system I for nitrate uptake in most cases was sufficient to explain the observed growth rates.     

Efflux of Potassium from Wheat Roots Induced by Changes in the Water Potential of the Root Medium

Growth of Plantago major L., ssp. major L. and ssp. pleiosperma Pilger and P. maritime L. was followed at two levels of mineral nutrition (low-salt and high-salt). In addition the response of transfer of plants from low-salt conditions to high-salt conditions and vice versa was studied. Growth of the studied Plantago species was strongly stimulated by high-salt conditions. The Ca²⁺- and Mg²⁺-stimulated ATPase activity of microsomal preparations of the roots was also studied. In P. major ssp. major and P. maritime a major pH optimum was observed at pH 6.5, and in addition a second pH optimum was found at pH 8.0. High-salt plants of these two species were characterized by biphasic stimulation curves for Ca²⁺ and Mg²⁺, whereas P. major ssp. pleiosperma showed a monophasic pattern. The ATPase activity per g dry weight of P. major and P. maritima was highest in high-salt plants. The species investigated here are adapted to relatively nutrient-rich conditions, and the properties of ATPases (K_m, K_max, protein content) and the growth responses are discussed in relation to this ecological property.     

Leaf fluctuating asymmetry of common plantain as an indicator of habitat quality

Abstract

Although developmental instability (DI), measured as fluctuating asymmetry (FA), is expected to be positively related to environmental stress and negatively to habitat quality, the pattern found here was the reverse. Developmental instability of leaf traits (leaf width and vein distances within a leaf) was estimated (using two indices of FA: FA₄ and σ_i ²) and compared between three populations of Plantago major L. (Plantaginaceae) from northern Serbia. Two of the populations are from chronically polluted areas (Karaburma & Zemun), while Crni Lug is from an unpolluted, natural area. Results obtained using both FA indices were the same; higher asymmetry levels in the unpolluted area than in the polluted sites, were found for both traits. Between the two polluted sites, FA values were significantly higher in Karaburma site for vein distances within a leaf. Concerning differences in FA₄ values between samples, in two cases, results are similar to those found for σ_i ² values, for vein distances within leaf. These are the first quantitative data on P. major indicating that (i) plants living in the stressful sites are more symmetrical and (ii) leaf FA for plant species with wide ecological distribution such as P. major should be considered as an ‘index of habitat quality.’     

Neighbor species differentially alter resistance phenotypes in Plantago

In this study, we investigated how neighbors (i.e., competitors) altered resistance phenotypes, namely plant size and levels of secondary compounds (iridoid glycosides), of individual plants and specifically tested whether neighbor identity mattered. We conducted a greenhouse experiment with Plantago lanceolata and Plantago major (Plantaginaceae) in which each species served as focal plants as well as neighbors in a factorial design. In addition, we harvested plants six and nine weeks after transplantation to test whether effects changed as plants grew. In both species, competition reduced plant size, and this effect increased over time. Plantago lanceolata neighbors suppressed growth of both focal plant species more than P. major neighbors. Effects of competition on levels of secondary compounds were more complex. Concentrations of iridoid glycosides were increased by competition in both species at harvest one. By the second harvest, an effect of competition on iridoid glycosides was found only in P. major. Neighbor identity influenced levels of iridoid glycosides in P. lanceolata at harvest one; concentrations were higher in plants grown with P. lanceolata neighbors than in plants grown with P. major neighbors. We also tested whether there was a trade-off between growth (biomass) and defense (levels of iridoid glycosides). Biomass and iridoid glycoside content were significantly correlated only in plants grown with competition and harvested at nine weeks, and this relationship was positive in both species, indicating that there was no trade-off between growth and defense. This study suggests that neighbor identity could play an important role in interspecific interactions, including the interactions of plants with other trophic levels.     

Chemical Fruit Thinning in Loquat with NAAm:Dosage, Timing, and Wetting Agent Effects

Effects of an increased lead (Pb) content in soil on growth, photosynthesis (P _N) and anatomical parameters of Plantago major L. plants grown under controlled conditions were studied. The total dry weights of plants at 500 and 2000 mg kg^–1 Pb in soil were correspondingly 70% and 54% of those of control plants. A reduced leaf area and changed leaf structure caused a decrease in P _N in the whole plant. The specific leaf weight (SLW) increased as compared with that of control plants. An increasing Pb content in soil caused a larger number of chloroplasts and larger sizes of protoplasts, a decrease in the chlorophyll a+b contents and a larger number of stomata per unit leaf area based both in adaxial and abaxial epidermis, as compared with control plants. However their conductance was from 40% to 50% lower than that in control plants. It was noted that the dimensions of conducting bundles decreased mainly because of the reduced xylem area. The lower functional activity and the changes at different structural levels of the photosynthetic apparatus caused a decrease in the growth rate of plants at a high Pb content in soil.     

Anti-mitotic and anti-genotoxic effects of Plantago lanceolata aqueous extract on Allium cepa root tip meristem cells

Plantago is the most important genus of Plantaginaceae family and is used in traditional medicine around the world for different purposes. Plantago coronopus L., Plantago major L., Plantago media L. and Plantago lanceolata L. are most commonly used species of Plantago in traditional medicine in Turkey. The main goal of this study was to investigate the eventual anti-mitotic and anti-genotoxic effects of P. lanceolata L. leaf aqueous extracts (15 g/L and 30 g/L) on Allium cepa L. root tip meristem cells which were treated with 0.7% hydrogen peroxide. For this purpose, two different experiments were performed under the same conditions. In the first experiment, Allium cepa onion bulbs were treated with 0.7% H₂O₂ for 1 h. After the H₂O₂ treatment, the onion bulbs were treated with two different concentrations (15 g/L and 30 g/L) of P. lanceolata extracts for 24 h. In the second experiment, A. cepa onion bulbs were treated with two different extract concentrations (15 g/L and 30 g/L) for 24 h and then with 0.7% H₂O₂ for 1 h. The test concentrations were determined according to doses which are recommended in alternative medicinal usage by people. As positive and negative control 0.7% H₂O₂ and tap water was used, respectively. As a result, it was determined that aqueous extracts reduced mitotic index and chromosome aberrations in treatment groups in comparison with controls. These results showed that P. lanceolata aqueous extracts have anti-mitotic and anti-genotoxic effects.     

Entrapment of herbal extracts into biodegradable microcapsules

The microcapsules with entrapped herbal water-soluble extracts of plantain Plantago major and calendula Calendula officinalis L. (PCE) were prepared by layer-by-layer (LbL)-adsorption of carrageenan and oligochitosan onto CaCO₃ microparticles with their subsequent dissolving after the treatment of EDTA. Entrapment of PCE was performed by using adsorption and co-precipitation techniques. The co-precipitation provided better entrapment of PCE into the carbonate matrix compared to adsorption. In vitro release kinetics (AGJ) was studied using artificial gastric juice. Using the model of acetate ulcer in rats it has been demonstrated that PCE released from the microcapsules accelerates gastric tissue repair.     

Comparison of Plantago Species from Nutrient-rich and Nutrient-poor Conditions: Growth Response, ATPases and Lipids of the Roots, as Affected by the Level of Mineral Nutrition

Two groups of Plantago species, one of relatively nutrient-rich habitats (Plantago major L., P. major L. ssp. pleiosperma Pilger and P. martrima L.) and the other of relatively nutrient poor habitats (P. lanceolata L., P. media L. and P. coronopus L.), were compared with respect to the response of the plants to alterations of the level of mineral nutrition. The comparison deals with growth response and root cell membrane functions (Ca²⁺ and Mg²⁺ stimulated ATPases and lipids). As far as these parameters are concerned species from relatively nutrientpoor habitats are not much affected by bringing the plants to high-salt conditions, while the reverse was true for species from relatively nutrient-rich habitats when transferred to low salt medium.     

A genetic investigation of the esters of caffeic acid with rhamnose or glucose in leaves of Plantago major

The genetic relationship between two sugar esters of caffeic acid in the leaves of Plantago major has been investigated. The difference is shown to be due to a single gene. Glucose accounts for the sugar part in the dominant phenotype while in the recessive type the sugar is rhamnose. This difference is only partly correlated with the division of the species into subspecies. The rhamnose type is found only in P. major ssp. pleiosperma Pilger, although only in less than half of the plants investigated.     

Genetic variability in Plantago species in relation to their ecology

Summary Twelve Plantago major plants, good representatives of their populations, appeared to be genetically different for several characters which are important for adaptation to the respective habitat conditions. These characters are: juvenile growth, leaf morphology, production of secondary rosettes, flowering time, seed production, seed size and adult leaf production. The adaptive value of some of these characters was investigated by transplantation experiments in the field and by intraspecific competition experiments. The roadside type of ssp. major was adapted to trampling by being erect and elastic. The lawn type of ssp. major was adapted to a short, frequently cut, vegetation by being prostrate and by producing leaves with short petioles throughout the growth season. In the natural situations in which ssp. pleiosperma occurs, growth rate and first-year seed production of this subspecies were considerably higher than that of ssp. major. In a number of experiments, F₁s and F₂s were included, derived from crosses between the original plants. The F₁s were generally rather well adapted to both parental habitats, whereas the F₂s appeared to be less fit. The various alternatives in spending resources relevant for fitness optimization in different habitats are discussed.Grassland Species Research Group Publication No. 93     

A new hydroxyolefinic acid from Plantago major seed oil

A new isomer of ricinoleic acid has been found as a minor constituent (1.5%) of the seed oil of Plantago major. This previously unknown β-hydroxyolefinic acid, 9-hydroxy-cis-11-octadecenoic, was characterized by IR, ¹H NMR and oxidative cleavage, and the structure was supported by MS.     

Comparison of the Respiratory Metabolism of Plantago lanceolata L. and Plantago major L.

Bryce, J. H. and ap Rees, T. 1985. Comparison of the respiratorymetabolism of Plantago lanceolata L. and Plantago major L.—J.exp. Bot. 36 1559–1565. The aim of this work was to discover if the respiratory metabolismof the roots of Plantago lanceolata L. differed from that ofthe roots of Plantago major L. Measurements of oxygen uptakeand dry weight of excised root systems during growth of seedlingsprovided evidence that the two species differed in the amountof respiration needed to support a given increase in dry weight.Excised root systems were given a 6-h pulse in [U-¹⁴C]sucrosefollowed by a 16.5-h chase in sucrose. The detailed distributionof ¹⁴C amongst the major components of the roots at the endof the pulse and the chase revealed no significant differencebetween the two species. Patterns of ¹⁴CO₂ production from [1-¹⁴C],[2-¹⁴C], [3,4-¹⁴C], and [6-¹⁴C]glucose of excised root systemsfrom plants of three ages were similar for the two species.It is suggested that there is no conclusive evidence for anysignificant inherent difference in the respiratory metabolismof the roots of the two species. Key words: ¹⁴C sugar metabolism, respiration, roots, Plantago     

Ascorbate in the leaf apoplast is a factor mediating ozone resistance in Plantago major

The role of ascorbate in mediating ozone resistance was examined in Plantago major L. Seedlings of eleven populations which exhibited differential resistance to ozone were fumigated in controlled environment chambers with charcoal/Purafil®-filtered air (CFA) or CFA plus 15 nmol·mol^–1 ozone overnight rising to a maximum between 12:00–16:00 hours of 75 nmol·mol^–1 for 14 d. Measurements of ascorbate content were made on apoplastic and symplastic extracts. Populations differed in their constitutive level of ascorbate in youngest fully expanded leaves, and regression analysis revealed a significant correlation between ascorbate content in ozone-treated leaves and the ozone resistance of the populations. The relationship was stronger using apoplastic ascorbate levels than with corresponding symplastic measurements. The ascorbate content of the youngest fully expanded leaf of an ozone sensitive population was increased by foliar application of ascorbate. No significant difference in stomatal conductance was found between control and ascorbate-treated plants. Following spraying, plants were fumigated with 400 nmol·mol^–1 ozone for 7 h. In control plants, ozone exposure resulted in extensive visible leaf damage (20–70 % at the end of the fumigation period) and decreased rates of CO₂ assimilation (–57 %). However, ascorbate treatment prevented the appearance of visible injury, and ameliorated the decline in photosynthesis induced by ozone (–26 %). Modelled data estimating the extent of protection afforded by apoplastic ascorbate against ozone supported the experimental observations. The results suggested that although apoplastic ascorbate plays an important role, other factors must also contribute to the mediation of ozone resistance in P. major.     

Root Respiration and Growth in Plantago major as Affected by Vesicular-Arbuscular Mycorrhizal Infection

Effects of vesicular-arbuscular mycorrhizal (VAM) infection and P on root respiration and dry matter allocation were studied in Plantago major L. ssp. pleiosperma (Pilger). By applying P, the relative growth rate of non-VAM controls and plants colonized by Glomus fasciculatum (Thaxt. sensu Gerdemann) Gerdemann and Trappe was increased to a similar extent (55-67%). However, leaf area ratio was increased more and net assimilation rate per unit leaf area was increased less by VAM infection than by P addition. The lower net assimilation rate could be related to a 20 to 30% higher root respiration rate per unit leaf area of VAM plants. Root respiration per unit dry matter and specific net uptake rates of N and P were increased more by VAM infection than by P addition. Neither the contribution of the alternative respiratory path nor the relative growth rate could account for the differences in root respiration rate between VAM and non-VAM plants. It was estimated that increased fungal respiration (87%) and ion uptake rate (13%) contributed to the higher respiratory activity of VAM roots of P. major.     

Transmission of a New Mycoplasma-Like Organism (MLO) from Cuscuta odorata (Ruiz et Pav.) to Herbaceous Plants and Attempts to its Elimination in the Vector

A new MLO-type, originating from a holoparasite plant Cuscuta odorata (Ruiz et Pav.) causing stunting and reduction of flower- and leaf size on Catharanthus roseus (L.) G. Don. (HEINTZ 1986) was transmitted to Apium graveolens L., Plantago major L., Bellis perennis L. and Cirsium japonicum hybrid. The observed symptoms on the test plants probably caused by the MLO have not yet been described in the literature. The symptomatology on these herbaceous plants gives further data in order to classify the MLO as a new one which is named Guscuta latent MLO (Cl-MLO). Attempts to transmit the pathogens by the leafboppers Euscelidius variegates (Kirschbaum) and Euscelis lineolatus (Brullé) failed. It also was impossible to elimmate the MLO completely from Cuscuta odorata by heat treatment and antibiotic application. However, we succeeded in eliminating the pathogens from Catharanthus roseus by heat treatment.