Equilibrium between basic nitrogen compounds in lupin seeds with differentiated alkaloid content

The results of studies on the content of the nitrogen basic compounds, viz. quinolizidine alkaloids, biogenic polyamines and basic amino acids in lupin seeds are presented. The investigations concerned three lupin species (Lupinus angustifolius L., Lupinus albus L. and Lupinus luteus L.) and 10 bitter and sweet cultivated varieties. Content of quinolizidine alkaloids in L. angustifolus ranged from 11.4 to 19.6 microg mg(-1) dw (bitter cultivars), from 0.18 to 0.47 microg mg(-1) dw (sweet), in L. albus from 0.58 microg mg(-1) dw (sweet) to 29.6 microg mg(-1) dw (bitter) and in L. luteus from 0.59 (sweet) to 14.7 microg mg(-1) dw (bitter). Total biogenic polyamine content ranged in L. angustifolius from 2,773.9 to 3,180.2 pmol mg(-1) dw (bitter) and from 315.0 to 599.0 pmol mg(-1) dw (sweet), in L. albus from 432.6 pmol mg(-1) dw (sweet) to 1,832.0 pmol mg(-1) dw (bitter) and in L. luteus from 506.9 pmol mg(-1) dw (sweet) to 2,091.8 pmol mg(-1) dw (bitter). Total basic amino acids varied in L. angustifolus from 1,034.3 to 1,704.6 pmol mg(-1) dw (bitter) and from 1,761.9 to 2,101.9 pmol mg(-1) dw (sweet), in L. albus from 696.9 pmol mg(-1) dw (bitter) to 1,269.2 pmol mg(-1) dw (sweet) and in L. luteus from 927.6 pmol mg(-1) dw (bitter) to 1,598.3 pmol mg(-1) dw (sweet). We found a close dependence between alkaloid content and level of biogenic polyamines and basic amino acids in all three lupin species tested. All bitter lupin seeds also contain high level of biogenic polyamines but a low content of basic amino acids. The reverse relationship in sweet lupin seeds was found. The findings demonstrate that lupin nitrogen basic compounds are in steady equilibrium and that change of content in one compound leads to corresponding change in the content of another.     

Potassium nutrition effects on seed alkaloid concentrations,yield and mineral content of lupins (Lupinus angustifolius)

To ensure that narrow-leafed lupin (Lupinus angustifolius L.) meets feed quality standards, the concentration of alkaloids must be kept under the maximum acceptable limit of 200 mg kg^–1 DM. One of the factors that may affect seed alkaloid concentration is soil nutrient deficiency. In this paper, we report the results of glasshouse and field experiments that tested the effect of potassium (K) deficiency on seed alkaloid concentrations. In the glasshouse, seed alkaloid concentrations increased by 385, 400 and 205% under severe K deficiency in sweet varieties (Danja, Gungurru and Yorrel, respectively) of L. angustifolius. The concentration of alkaloids in Fest, the bitter variety, was always high regardless of soil K status. At all levels of applied K (0–240 mg kg^–1 soil), lupanine was the predominant alkaloid in sweet varieties, whereas 13-hydroxylupanine prevailed in the bitter variety. Seed yield of all varieties increased exponentially with increasing amounts of applied K, reaching a maximum at 60 mg K kg^–1 soil. In the field, application of K to deficient soils decreased seed alkaloid concentration at Badgingarra, Western Australia (WA) but not at Nyabing, WA, in 1996. In both field trials, seed yield and mineral content were not affected by the amounts of K fertiliser applied. These findings highlighted the need for adequate K fertilisation of deficient soils in WA to avoid the risk of producing low quality lupin seed with high alkaloid concentrations. K deficiency is involved in stimulating alkaloid production in sweet varieties of L. angustifolius.     

Synthesis, transport and accumulation of quinolizidine alkaloids in Lupinus albus L. and L. angustifolius L

Each of the principal quinolizidine alkaloids (QA) found in both xylem and phloem exudates together with extracts from all component organs collected from bitter (cv. Lupini) and sweet (cv. Ultra) cultivars of Lupinus albus L. were quantified by gas chromatographic analyses throughout reproductive development. In addition to establishing the major translocated QA species estimates for fluxes of QA to developing fruits based on their sap composition and water economy showed that around half of the QA that accumulated in fruit tissues was due to synthesis in situ and half to translocation principally by phloem. Detailed analyses of QA in transport fluids and component organs were extended to reciprocal homo- and hetero-grafts using bitter (cv. Fest) and sweet (cv. Danja) cultivars of L. angustifolius L. These data confirmed that the majority of QA were synthesized in shoot tissues. In both lupin species feeding and analysis of deuterated QA (lupanine and 13-hydroxylupanine) were used as tracers to demonstrate direct redistribution of alkaloids by translocation from mature leaves in phloem.     

Development of a sequence-specific PCR marker linked to the gene “pauper” conferring low-alkaloids in white lupin (Lupinus albus L.) for marker assisted selection

Seeds and plants of wild type Lupinus albus are bitter and contain high level of alkaloids. During domestication, at least three genes conferring low-alkaloid content were identified and incorporated into commercial varieties. Australian lupin breeders exclusively utilize one of these sweetness genes, “pauper”, in all varieties to prevent possible bitterness contamination via out-crossing. A cross was made between a sweet variety Kiev Mutant (containing pauper gene) and a bitter type landrace P27174, and the population was advanced into F₈ recombinant inbred lines (RILs). Twenty-four plants representing sweetness and bitterness were subjected to DNA fingerprinting by the microsatellite-anchored fragment length polymorphism (MFLP) technique. A dominant polymorphism was discovered in an MFLP fingerprint. The MFLP marker was converted into a co-dominant, sequence-specific, simple PCR-based marker. Linkage analysis by the software program MapManager with marker score data and alkaloid phenotyping data from a segregating population containing 190 F₈ RILs indicated that the marker is linked to the pauper gene at the genetic distance of 1.4 centiMorgans (cM). This marker, which is designated as “PauperM1”, is capable of distinguishing the pauper gene from the other two low-alkaloid genes exiguus and nutricius. Validation on germplasm from the Australian lupin breeding program showed that the banding pattern of the marker PauperM1 is consistent with the alkaloid genotyping on a wide range of domesticated varieties and breeding lines. The PauperM1 marker is now being implemented for marker assisted selection in the Australian albus lupin breeding program.     

INFLUENCE OF THE QUINOLIZIDINE ALKALOID CONTENT OF LUPINUS ALBUS (FABACEAE) ON THE FEEDING CHOICE OF HELIX ASPERSA (GASTROPODA: PULMONATA)

Adult Helix aspersa snails were maintained individually forone week in plastic cages with 9 living Lupinus albus plantsas their only food. Among these 9 plants, 3 chemotypes bitter,intermediate and sweet which differed in their alkaloid contentwere equally represented. Each day, the leaf surface grazed and the number of leaves attackedby the snails were recorded for each chemotype and each snail.A consumption/ attack (C/A) ratio was calculated by dividing thesurface grazed (C) by the number of attacks (A). The numberof attacks and the grazed area were positively correlated foreach chemotype during the whole experiment, and the snails atesimilar quantities of lupin each day. After 4 and 6 days ofexperiment, we noticed a rejection of the bitter chemotype infavor of the intermediate and sweet ones respectively. Afterthe 6th day, the surface grazed per attack was significantlyhigher on the sweet chemotype than on the bitter plants. Wehypothesize that rejection of the bitter chemotype might berelated to (i) an alkaloids reaction threshold associated withan increase in the amount of alkaloids in the wounded plantsand/or (ii) aversive ingestive conditioning. (Received ; accepted 16 April 1999)     

The interaction of phosphorus and potassium with seed alkaloid concentrations, yield and mineral content in narrow-leafed lupin (Lupinus angustifoliusL.)

We tested the impact of P deficiency, K deficiency, and their interaction on seed alkaloid concentrations and profile, yield and mineral content in sweet (low-alkaloid) and bitter (high-alkaloid) varieties of narrow-leafed lupin (Lupinus angustifolius L.). P deficiency reduced seed alkaloid concentrations in sweet, but not in bitter, varieties. Under P deficiency, the alkaloid profile in harvested seed of sweet varieties mimicked that of the bitter variety Fest, with 13-hydroxylupanine dominating over lupanine. With adequate or abundant P, lupanine was the predominant alkaloid in sweet varieties. K deficiency was associated with an 8-fold increase of seed alkaloid concentrations in the sweet variety Danja (from 1000 to 8000 mg kg^–1 DM), mostly due to the stimulation of lupanine production. There was a significant interaction between P and K that affected seed alkaloid concentrations in two ways: (i) the inhibitory effect of P deficiency was only apparent under K deficiency and (ii) the lowest seed alkaloid concentrations occurred with abundant K (240 mg K kg^–1) and P (60 mg P kg^–1). Seed yield of all varieties increased asymptotically with increasing P and reached a maximum at adequate P (30 mg P kg^–1). There was no impact of K deficiency on seed yield. In sweet and bitter varieties P supply increased seed N, P and Zn concentrations, but not K. In contrast, seed K concentrations increased and P concentrations decreased with increasing K supply. These findings suggest that P fertiliser should be supplemented with K, to avoid high seed alkaloid concentrations stimulated by asymptomatic K deficiency at high P levels.     

Feeding preferences of the weevils Sitona gressorius and Sitona griseus on different lupin genotypes and the role of alkaloids

The weevils Sitona gressorius and Sitona griseus are specialist herbivores on lupins in Europe. The adult weevils feed on the leaves, and the larvae on the root nodules of the plants. This causes severe damage to lupin crops. In the present study, the feeding preferences of lupin weevil adults on different lupin genotypes were examined with respect to a possible effect of lupin alkaloids on host selection. A total of 12 genotypes from the species Lupinus albus, L. angustifolius, L. luteus, and L. nanus were grown in a field experiment and the feeding damage on the leaves caused by naturally occurring lupin weevil adults was estimated. Additionally, a feeding choice test with S. gressorius adults was performed to examine feeding preferences under laboratory conditions. A gas chromatographic analysis provided information on the alkaloid content and profiles in the leaves of the tested lupin genotypes. In the field experiment, significant differences in the extent of the feeding damage within the 12 lupin genotypes were observed. The dual-choice feeding bioassay did not show discrimination of lupin species, but two L. angustifolius genotypes were significantly less affected than the standard L. luteus “Bornal”. The alkaloid analysis revealed large contrasts in alkaloid concentrations and profiles in the leaves of the tested genotypes. Correlation analysis with the results from the field and laboratory did not indicate a significant influence of the total foliar alkaloid content on the extent of weevil feeding.     

European yellow lupine, Lupinus luteus, and narrow-leaf lupine, Lupinus angustifolius, as hosts for the pea aphid, Acyrthosiphon pisum

The pea aphid, Acyrthosiphon pisum Harris (Homoptera: Aphididae), fed, developed, and reproduced on yellow lupine, Lupinus luteus L. (Fabaceae: Genisteae). No clear preferences for any variety within L. luteus were found. Acyrthosiphon pisum showed negative values of relative growth rate and no aphid completed development on any variety of narrow-leaf lupine Lupinus angustifolius L. Aphids did not ingest phloem sap while probing on L. angustifolius and the probes were very short. All varieties of L. angustifolius were rejected by aphids during an early stage of probing in peripheral tissues, that is, epidermis or mesophyll. There were qualitative and quantitative differences in alkaloid and soluble sugar content between the two lupine species. Within species, the relative content of individual compounds differed among the varieties. Lupinus angustifolius contained four quinolizidine alkaloids (13-hydroxylupanine, dehydrolupanine, lupanine, and angustifoline), while L. luteus contained two (lupanine and sparteine). Lupanine occurred in all varieties of both lupine species. The total content of soluble carbohydrates was similar in L. luteus and L. angustifolius . The following cyclitols were found in both lupine species: myo -inositol, D-ononitol, and D-pinitol. Lupinus angustifolius also contained D- chiro -inositol. The study of aphid probing behaviour, development, and reproduction demonstrated that L. luteus is a suitable host plant for A. pisum while L. angustifolius is not. It is likely that the rejection of L. angustifolius by A. pisum was caused by chemical factors detected by aphids at the epidermis and mesophyll level.     

Aphids do not avoid resistance in Australian lupin (Lupinus angustifolius, L. luteus) varieties

Laboratory bioassays and field trials were used to characterize resistance to three aphid species (Myzus persicae (Sulzer), Acyrthosiphon kondoi Shinji, Aphis craccivora (Koch) in two aphid-resistant varieties (Kalya, Tanjil) and one susceptible variety (Tallerack) of Lupinus angustifolius L., and in one resistant variety (Teo) and one susceptible variety (Wodjil) of L. luteus L. Host selection tests in the glasshouse showed that alates of all three species preferred L. luteus to L. angustifolius, but provided no evidence that alates selected susceptible varieties over resistant. These results were supported by a field trial, which showed no difference in the number of colonizing A. kondoi alates collected from the resistant and susceptible lines of each lupin species, but there were significantly more late-instar nymphs and apterous adults on the susceptible lines. In laboratory host suitability experiments, there was much greater suppression of aphid growth and survival on Teo than on Kalya and Tanjil. In field trials, the numbers of aphids were generally lower on resistant compared to susceptible lines of both lupin species with one notable exception: M. persicae numbers were not lower on the resistant variety Tanjil compared to the susceptible variety Tallerack (L. angustifolius). These results suggest that the resistance mechanisms in both lupin species do not affect the selection of hosts by colonizing aphids, but rather are affecting the growth, survival and possibly reproduction of aphids after settling.     

The first genetic and comparative map of white lupin (Lupinus albus L.): identification of QTLs for anthracnose resistance and flowering time, and a locus for alkaloid content.

We report the first genetic linkage map of white lupin (Lupinus albus L.). An F8 recombinant inbred line population developed from Kiev mutant x P27174 was mapped with 220 amplified fragment length polymorphism and 105 gene-based markers. The genetic map consists of 28 main linkage groups (LGs) that varied in length from 22.7 cM to 246.5 cM and spanned a total length of 2951 cM. There were seven additional pairs and 15 unlinked markers, and 12.8% of markers showed segregation distortion at P < 0.05. Syntenic relationships between Medicago truncatula and L. albus were complex. Forty-five orthologous markers that mapped between M. truncatula and L. albus identified 17 small syntenic blocks, and each M. truncatula chromosome aligned to between one and six syntenic blocks in L. albus. Genetic mapping of three important traits: anthracnose resistance, flowering time, and alkaloid content allowed loci governing these traits to be defined. Two quantitative trait loci (QTLs) with significant effects were identified for anthracnose resistance on LG4 and LG17, and two QTLs were detected for flowering time on the top of LG1 and LG3. Alkaloid content was mapped as a Mendelian trait to LG11.     

A quinolizidine alkaloid O-tigloyltransferase gene in wild and domesticated white lupin (Lupinus albus)

Wild white lupins have high levels of alkaloids, which cause a bitter taste, whereas domesticated white lupin varieties have a very low content of alkaloids in seeds. Genes for bitterness from wild white lupins are a contamination threat to domesticated white lupin via cross‐pollination. The gene(s) for alkaloid synthesis have not been clearly identified, and the associated molecular background among wild white lupin, domesticated and contaminated domesticated plant materials is unknown. So far, only tigloyl‐CoA:(?)‐13alpha‐hydroxymultiflorine/(+)‐13alpha‐hydroxylupanine O‐tigloyltransferase (HMT/HLTase) cDNA has been cloned based on protein analysis, which was suggested as encoding a quinolizidine alkaloid transferase regulating quinolizidine alkaloid biosynthesis. This gene has not yet been well characterised in important white lupin genotypes. In this study, we found that the majority of the intron sequence of the HMT/HLTase gene differed between wild white lupin accessions P25758 and P27593, and between the commercial varieties. The expression pattern as well as the expression level of the HMT/HLTase gene showed no difference between the P25758 and the low‐alkaloid variety Kiev mutant, suggesting the expression of the HMT/HLTase gene has no correlation with bitterness. However, the intron sequence is useful as a DNA marker in the identification of the contamination source of bitter seeds in commercial lupin seed lots.     

Transfer of quinolizidine alkaloids from hosts to hemiparasites in two Castilleja-Lupinus associations: analysis of floral and vegetative tissues

Many hemiparasites, including several members of the Castilleja genus (Scrophulariaceae), obtain secondary compounds from their host plants. Both Castilleja miniata in subalpine Colorado and C. indivisa in central Texas have reduced herbivory when obtaining alkaloids from the hosts Lupinus argenteus and L. texensis (Fabaceae), respectively. However, pollinators were not deterred from visiting Castilleja parasitizing alkaloid-containing hosts. To determine if alkaloids are present in all tissues of plants parasitizing lupins, we analyzed floral tissue as well as leaves of both Castilleja species. Leaves, bracts, calices, corollas, gynoecium and nectar of both Castilleja species were examined for quinolizidine alkaloid presence using a Dragendorff reagent, and alkaloids were identified in vegetative tissue and nectar by capillary GLC and GLC-MS. Lupanine and alpha-isolupanine were the principal alkaloids in C. indivisa parasitizing L. texensis, while principal alkaloids of C. miniata parasitizing L. argenteus were 5,6-iso-dehydrolupanine, alpha-isolupanine, thermopsine, and 17-oxolupanine. Except for 17-oxolupanine, which was probably synthesized by biotransformation in the parasite, all other alkaloids correspond to those present in the host plants. Alkaloids were present in the leaves of both Castilleja species, and in the bracts, calices and gynoecium of some plants, but never in the corollas. Alkaloids from L. texensis and L. argenteus were not detected in nectar of either Castilleja species. The presence of alkaloids in leaves and outer floral tissue of both Castilleja species, but not nectar, may explain why alkaloid uptake and storage affected herbivores but not pollinators.     

Quinolizidine alkaloid profiles of Lupinus varius orientalis, L. albus albus, L. hartwegii, and L. densiflorus

Alkaloid profiles of two Lupinus species growing naturally in Egypt (L. albus albus [synonym L. termis], L. varius orientalis) in addition to two New World species (L. hartwegii, L. densiflorus) which were cultivated in Egypt were studied by capillary GLC and GLC-mass spectrometry with respect to quinolizidine alkaloids. Altogether 44 quinolizidine, bipiperidyl and proto-indole alkaloids were identified; 29 in L. albus, 13 in L. varius orientalis, 15 in L. hartwegii, 6 in L. densiflorus. Some of these alkaloids were identified for the first time in these plants. The alkaloidal patterns of various plant organs (leaves, flowers, stems, roots, pods and seeds) are documented. Screening for antimicrobial activity of these plant extracts demonstrated substantial activity against Candida albicans, Aspergillus flavus and Bacillus subtilis.     

Triticum aestivum shows a greater biomass response to a supply of aluminium phosphate than Lupinus albus, despite releasing fewer carboxylates into the rhizosphere

The relationship between carboxylate release and the ability of plants to access phosphorus from AlPO4 and to detoxify aluminium was studied by comparing species with a low and high rate of carboxylate release, Triticum aestivum (wheat) and Lupinus albus (white lupin), respectively. Species were supplied with P at 10, 20, 40 or 100 mg P kg-1 sand in the form of sparingly soluble AlPO4 or soluble KH2PO4; control plants did not receive any P. Triticum aestivum was significantly better than L. albus at accessing P from AlPO4, despite accumulating fewer carboxylates in its rhizosphere. Rhizosphere pH of L. albus did not vary with form or level of P supply, while the rhizosphere pH of T. aestivum increased with the level of P supplied. Based on the evidence in the present study, a model is proposed to explain the poor performance of L. albus, whereby the release of carboxylates and associated protons reduces the chelating ability of exuded carboxylates, thus reducing P acquisition and increasing Al toxicity.     

Influence of leaf age and light environment on the gas exchange of lupins and wheat

Rates of net photosynthesis (A), transpiration (E) and leaf conductance to water vapour transfer (gH₂O) were measured on leaves of Lupinus angustifolius L. cv. Ritson's and L. cosentinii Guss. cv. Eregulla throughout development and on flag leaves of wheat ( Triticum aestivum L. cvs Gutha, Gamenya and Warigal) after full expansion. Plants were grown in large containers of soil, in a naturally-lit, temperature controlled glasshouse. Throughout most of their life, lupin leaves had higher photosynthetic rates and leaf conductances than found for wheat. During leaf ageing in lupins, photosynthesis and conductance changed proportionately such that leaf intercellular CO₂ concentration was maintained relatively constant at about 200 ppm. Under continuously cloudy conditions, leaf conductance at midday of lupins and wheat was higher than at similar photon flux densities at other times of day on cloudless days. On cloudy days the relationship between gH₂O and photon flux density in lupins was very different from that derived from diurnal measurements on clear days. The potentially low water use efficiency under cloud, evident as decreases in the A/gH₂O ratio, was rarely realised in practise due to a reduction in leaf-to-air water vapour concentration difference on cloudy days. The possible reasons for the high conductance on cloudy days are discussed.     

Influence of day length and temperature on number of main stem leaves and time to flowering in lupin

A growth chamber experiment was carried out to investigate the influence of day length and temperature on the development of flowering in eight varieties of the three grain lupin species Lupinus albus (Wat and C3396), L. angustifolius (Gungurru, Polonez and W26) and L. luteus, (Juno, Radames and Teo). The plants were grown at two temperatures, 10°C and 18°C, in combination with five daylength regimes: 10, 14, 18, 24 h day at full light intensity and 10 h full light extended with 8 h low intensity light. Increased daylength decreased days from sowing to flowering in all varieties, but had little effect on thermal time to flowering in most varieties. However, C3396, W26 and Radames had a significantly longer thermal time to flowering at high, non‐vernalising temperature (18°C) at short daylengths. Low light intensity daylength extension did not significantly influence thermal time to flowering. For flower initiation, measured as number of leaves on the main stem three types of response were found. All varieties formed fewer leaves on the main stem at 10°C than at 18°C, although the two thermo‐neutral varieties of L. luteus, Juno and Teo, gave only a small response to temperature and daylength. In Polonez, Gungurru and Wat, low temperature decreased leaf number, but there was only a small response to changes in daylength. Three varieties, C3396, W26 and Radames, showed longer thermal time to flowering at 18°C with short daylengths. This could be explained by a greater number of main stem leaves formed at short daylength at non‐vernalising temperatures. Increased daylength decreased leaf number in these varieties, but never to a smaller number than for plants grown at 10°C. In these varieties, low intensity extension of the daylength had a similar (W26, Radames) or decreased (C3396) effect compared to full light extension. The hastening of time to flowering by long days could be separated into two effects: a high light energy effect hastened development by increasing the rate of leaf appearance in all varieties, while low light energy in thermo‐sensitive varieties was able to substitute for vernalisation by decreasing leaf number.     

Heavy metals in white lupin: uptake, root-to-shoot transfer and redistribution within the plant

The translocation of manganese (Mn), nickel (Ni), cobalt (Co), zinc (Zn) and cadmium (Cd) in white lupin (Lupinus albus cv. Amiga) was compared considering root-to-shoot transport, and redistribution in the root system and in the shoot, as well as the content at different stages of cluster roots and in other roots. To investigate the redistribution of these heavy metals, lupin plants were labelled via the root for 24 h with radionuclides and subsequently grown hydroponically for several weeks. 54Mn, 63Ni and 65Zn were transported via the xylem to the shoot. 63Ni and 65Zn were redistributed afterwards via the phloem from older to younger leaves, while 54Mn remained in the oldest leaves. A strong retention in the root was observed for 57Co and 109Cd. Cluster roots contained higher concentrations of all heavy metals than noncluster roots. Concentrations were generally higher at the beginning of cluster root development (juvenile and immature stages). Mature cluster roots also contained high levels of 54Mn and 57Co, but only reduced concentrations of 63Ni, 65Zn and 109Cd.     

Alkaloid profile of leaves and seeds of Lupinus hintonii C. P. Smith

L. hintonii C. P. Smith grows in the Central Highland forests of Mexico at altitudes between 2800 m to 3200 m above see level. Members of the genus Lupinus produce quinolizidine alkaloids as main chemical defensive compounds against herbivores. Surprisingly alkaloid profiles are rather constant within this species, while substantial variation was found when compared to morphologically closely related other taxa. As part of a phytochemical project on Mexican wild lupins, we report on the alkaloid profiles of seeds and leaves of L. hintonii. 19 alkaloids could be identified by capillary GLC-MS. Six major alkaloids occurred in leaves and seeds: 13-hydroxylupanine (28% and 45% respectively), tetrahydrorhombifoline (31% and 23% respectively), angustifoline (2% and 4% respectively), lupanine (7% and 5% respectively), 13alpha-tigloyloxylupanine (19% and 5% respectively) and 4alpha-angeloyl-3beta-hydroxylupanine (9% and 2%). This chemical pattern resembles that of the North American lupin L. floribundus.     

Profiling changes in metabolism of isoflavonoids and their conjugates in Lupinus albus treated with biotic elicitor

Liquid chromatography with ultraviolet and mass spectrometric detection was applied to monitor changes in profiles of isoflavonoid glycosides and free isoflavonoid aglycones in Lupinus albus L. Four isoflavonoid aglycones, fourteen isoflavonoid glycosides, four flavonol glycosides and flavone glycoside were identified in lupin tissue after LC/ESI/MS analyses. An elicitor preparation from purified yeast cell wall was used to inject the shoots of 3-week old seedlings or to infiltrate the cut lupin leaves. Qualitative and quantitative changes of isoflavonoids were measured at different time points after elicitation. In elicited lupin seedlings increased amounts of prenylated isoflavone aglycones were identified. The concentrations of glycosidic conjugates of isoflavones present in plant tissue were less affected.     

Root-induced acidification and excess cation uptake by N2-fixing Lupinus albus grown in phosphorus-deficient soil

Plant and Soil - White lupin plants (Lupinus albus L. cv. Kiev) were grown in soil columns under controlled conditions at 20/12?°C (12/12 h) for 76 d to investigate the effect of...