Turnover of Storage Protein in Seeds of Soya Bean and Pea

We were interested in determining whether the low protein contentof pea seeds (Pisum sativum L.) as compared to soya bean seeds(Glycine max L. Merrill) might be due to faster degradationof the pea storage proteins during development of the seed.Pea and soya bean cotyledons were subjected to a ‘pulse-chase’experiment using [³H]glycine in in-vitro cultures. In peas,legumin had a half-life of 146 days, while vicilin had a half-lifeof 39 days. There was no measureable degradation of soya beanstorage proteins. Even with the pea storage proteins, the half-liveswere so much longer than the maturation time of seeds that degradationof storage proteins could not account for the lower proteincontent of peas as compared to soya beans. The validity of theseresults was indicated by the finding that non-storage proteinshad much shorter half-lives and that omission of a carbon ora nitrogen source greatly accelerated degradation. Labelledglycine was found to be a good probe for protein turnover studiesbecause it was very rapidly metabolized. Glycine max L. Merrill, soya bean, Pisum sativum, L. pea, protein turnover, storage proteins, legumin, vicilin     

Effects of Nutrient Supply on Seed Growth of Field Bean (Vicia faba L.). 1. Effects of Different Sulphur and Methionine Regimes on Cotyledon Growth, Protein and Uncombined Amino Acids In vivo

The effects of exogenous methionine on growth of developingVicia faba seeds in vivo was studied. Methionine (51 or 102µmol in total) injected into the base of the pod overa period of 15 d (26–40 d after pollination) decreasedgrowth and protein accumulation in proximal seeds but increasedin distal seeds. Distal seeds of methionine injected pods accumulatedmore d. wt and protein than distal seeds of water-injected pods.However, on a pod basis methionine reduced overall seed growthand protein accumulation. Exogenous methionine caused a relative increase in legumin buta decrease in vicilin. Injected methionine also affected thecomposition of uncombined amino acids, especially those derivedfrom aspartic acid. In contrast, the amino acid compositionof the protein fraction did not change appreciably. The data suggest that seed growth is not limited by methioninebiosynthesis but seed protein composition is regulated by methionine. Vicia faba L., field bean, cotyledon, growth, in vitro culture, uncombined amino acids, protein composition, legumin, vicilin, methionine, sulphur     

Changes during Development in the Nitrogen, Uncombined Amino Acid and Carbohydrate Contents of Cotyledons from Different Cultivars and Lines of Field Bean (Vicia faba L.)

A study has been made of the changes during development in thetotal nitrogen, uncombined amino acid, starch and ethanol-solublesugar contents of field bean cotyledons from two large-seededcultivars, Minica and Felix, and two lines of the small-seededcultivar Dacre, which differed in protein concentration of themature seed. In all cultivars the concentration of total nitrogen,uncombined amino acids and ethanol-soluble sugars decreasedwhile that of starch increased during development. However,the pattern of decrease in the proportion of total nitrogenvaried between the large and the small-seeded cultivars. Fromday 40 (after pollination) onwards a higher percentage of ethanol-solublesugars but a lower percentage of starch was found in the large-seededcultivars. Throughout development the Dacre line with the ‘high’protein concentration in the mature seed maintained a higherpercentage of total nitrogen and a correspondingly lower percentageof ethanol-soluble sugars and starch than the ‘low’protein line. Vicia faba L., field bean, nitrogen, starch, amino acids, sugars, protein     

The Development of Desiccation-tolerance and Maximum Seed Quality During Seed Maturation in Six Grain Legumes

‘Physiological maturity’, i.e. the time when seedsreach their maximum dry weight during development, occurredwhen maturation drying on the parent plant in the field hadreduced seed moisture content to approximately 60 per cent infaba bean (Vicia faba L.), lentil (Lens culinaris Medic.), chickpea(Cicer arietinum L.), white lupin (Lupinus albus L.), soya bean(Glycine max [L.] Merr.) and pea (Pisum sativum L.) The onsetof desiccation-tolerance, i.e. the ability of seeds to germinatefollowing harvest and rapid artificial drying, coincided withphysiological maturity, except in pea where it occurred a littleearlier at about 70 per cent moisture content. Maximum seedquality as determined by maximum viability, minimum seedlingabnormalities and maximum seedling size occurred in pea, chickpeaand lupin when seeds were harvested for rapid drying at physiologicalmaturity; but for maximum seed quality in the other speciesmaturation drying had to proceed further - to about 45 per centmoisture content in soya bean and to about 30 per cent moisturecontent in lentil and faba bean seed crops. Much of this variationamongst the six species, however, was due to differences inthe variation in maturity within each seed crop. Results forindividual pods showed that peak maturity, i.e. maximum seedquality following harvest and rapid artificial drying, was achievedin all six species once maturation drying had reduced the moisturecontent of the seeds to 45–50 per cent. In pea, faba beanand soya bean there was a substantial decline in viability andan increase in seedling abnormalities when harvest was delayedbeyond the optimal moisture content for harvest.     

Effects of Nutrient Supply on Seed Growth of Field Bean (Vicia faba L.). 1. Effects of Different Sulphur and Methionine Regimes on Cotyledon Growth, Protein and Uncombined Amino Acids In vitro

The effects of differemt S and methionine regimes on growthof developing Vicia faba cotyledons in vitro were studied. Basalmedium (containing adequate S) supplemented with 05 mM methioninemarginally increased d. wt and uncombined amino acid accumulationbut adding 1–5 mM methionine inhibited both growth andprotein accumulation. Sulphur deficiency reduced both d. wtand protein accumulation but incresed accumulation of uncombinedamino acids. Adding 1 mM methionine to the S-deficient mediumrestored growth, normal protein and uncombined amino acid acnunulation.High sulphate medium (7.5 mM ) decreased d. wt, protein anduncombined amino acid accumulation. High sulphate medium or basal medium+methionine (05 mM) changedthe proportions of the seed proteins; legumin increased butvicilin decreased. Sulphur deficiency caused a relative increasein vicilin but a decrease in legumin. The different S and methionineregimes markedly changed the composition of the uncombined aminoacids, especially those derived from aspartic acid but not thecomposition of the protein fraction, except during S deficiency. The data presented indicates a flexibility in the storage proteincomposition of developing cotyledons grown in vitro, with theS and methionine status having a regulatory effect. Vicia faba L., field bean, cotyledon, growth, in vitro culture, uncombined amino acids, protein composition, legumin, vicilin, methionine, sulphur     

Control of Seed Protein Accumulation in Field Bean (Vicia faba L.)

A study was made of the changes during development in the totalamino acid and 3, 4 dihydroxyphenylalanine (DOPA) content ofbean pod phloem sap, employing EDTA to aid phloem exudation.Two field bean lines, Dacre B and D, selected for their lowand high seed protein content respectively, were compared. Throughoutdevelopment, the sap samples of Dacre D had a greater aminoacid concentration than those from Dacre B. The sap of DacreB contained a higher proportion of DOPA than that of Dacre D.These two lines of Dacre were also studied with respect to accumulationof protein and uncombined amino acid in cotyledons grown bothin vitro and in vivo. Dacre D accumulated more total proteinthan Dacre B but contained a similar amount of uncombined aminoacids when grown in vivo. However, the amount of total proteinaccumulated was similar when the cotyledons were grown in vitro.The data suggest that the supply of nutrients to the pod maybe the basis of the different protein concentrations in themature seed of these lines. Vicia faba L., field bean, phloem sap, cotyledon culture, amino acids, DOPA, protein     

Amino Acid Release from the Seed Coat of Developing Seeds of Vicia faba and Pisum sativum

After removal of the embryo from developing ovules of Viciafaba L. and Pisum sativum L., seed-coat exudates were collectedand the amino acid fraction of the exudate was analyzed. InV. faba, alanine was the most important compound of the aminoacid fraction. In P. sativum, alanine and glutamine were thetwo most important components, whereas only small amounts ofasparagine were present. Comparison with published data suggeststhat seed-coat exudates may differ from phloem sap in the relativeimportance of these amino acids. Pisum sativum, pea, Vicia faba, broad bean, amino acid transport, amino acid unloading, seed-coat exudate, seed development     

Localization of the Fe(III)-Zn(II) Purple Acid Phosphatase in Dry Kidney Beans Using Immunofluorescence and Immunogold Electron Microscopy

Localization of purple acid phosphatase (PAP) from the seedsof kidney beans,Phaseolus vulgaris(L.), was performed usinglight and transmission electron microscopy. After rehydrationand aqueous fixation, cryo-sections of bean cotyledon tissueshowed a bright immunofluorescent signal in the cytoplasm ofcells whereas cell walls and reserve materials (starch, proteinbodies) remained unstained. In ultrathin sections of dry cotyledontissue anhydrously fixed in acrolein vapour and embedded inLowicryl resin, PAP mapped exclusively to ribosome-rich areasof the cytoplasm. In view of these results, we propose thatkidney bean PAP might possibly be engaged in mechanisms involvedin the triggering of seed dormancy.Copyright 1998 Annals ofBotany Company Phaseolus vulgaris(L.), kidney bean, purple acid phosphatase, immunofluorescence microscopy, immunogold electron microscopy, anhydrous vapour fixation, acrolein.     

Changes in the Contents of Free and Protein Amino Acids in Tobacco Seeds and Placentae during Maturation

Changes in the levels of protein and free amino acids in theseeds and placentae of Nicotiana tabacum were studied duringseed development. Seed maturation was completed 24 days afteranthesis. During maturation, protein rapidly accumulated inthe seeds between the 6th and 18th day, along with an appreciablecompositional change in the protein amino acids as the proportionsof glutamic acid and arginine increased. The amount of freeamino acids in the seeds gradually decreased throughout maturation.The major free amino acid on the 6th day after anthesis wasglutamine, which then drastically decreased between the 6thand 12th day with increases of glutamic acid, proline, arginineand alanine. The latter amino acids decreased thereafter untilthe 24th day. On the other hand, the amount and composition of the proteinsin the placentae did not change significantly throughout seedmaturation. In the early stage of development, the major freeamino acids in the placentae were glutamine, asparagine andglutamic acid, while in the later stage asparagine was mostabundant. (Received March 12, 1982; Accepted August 16, 1982)     

The cDNA cloning of a pea (Pisum sativum) seed lipoxygenase. Sequence comparisons of the two major pea seed lipoxygenase isoforms.

Cloning and sequencing of two cDNAs from mRNA of maturing pea (Pisum sativum) seeds allowed the deduction of the complete amino acid sequence of a lipoxygenase polypeptide which is most similar to that of soya-bean lipoxygenase 2. The predicted Mr of this polypeptide is 97134, and its sequence permits comparisons between the lox2-type and the lox3-type lipoxygenase isoforms from pea and soya bean (Glycine max).     

Lipases in the storage tissues of peanut and other oil seeds during germination

The castor-bean endosperm-the best-studied material of reserve lipid hydrolysis in seed germination-was previously shown to have an acid lipase and an alkaline lipase having reciprocal patterns of development during germination. We studied oil seeds from 7 species, namely castor bean (Ricinus communis L.), peanut (Arachis hypogaea L.), sunflower (Helianthus annus L.), cucumber (Cucumis sativus L.), cotton (Gossypisum hirsutum L.), corn (Zea mays. L.) and tomato (Lycopersicon esculentum Mill.). The storage tissues of all these oil seeds except castor bean contained only alkaline lipase activity which increased drastically during germination. The pattern of acid and alkaline lipases in castor bean does not seem to be common in other oil seeds. The alkaline lipase of peanut cotyledons was chosen for further study. On sucrose gradient centrifugation of cotyledon homogenate from 3-d-old seedlings, about 60% of the activity of the enzyme was found to be associated with the glyoxysomes, 15% with the mitochondria, and 25% with a membrane fraction at a density of 1.12 g cm^-3. The glyoxysomal lipase was associated with the organelle membrane, and hydrolyzed only monoglyceride whereas the mitochondrial and membrane-fraction enzymes degraded mono-, di- and triglycerides equally well. Thus, although the lipase in the glyoxysomes had the highest activity, it had to cooperate with lipases in other cellular compartments for the complete hydrolysis of reserve triglycerides.     

The Rate of Morphogenesis of Embryos and Seeds in Four Species of Grain Legumes

Comparative embryo development has been studied histologicallyin Lupinus albus, Lupinus mutabilis, Vicia faba, Pisum sativumand Latkyrus latifolius. The detailed histology of the stagesof embryo formation up to the early differentiation of tissuesof the seed is reported. The rate of embryogenesis has beentimed through 15 stages of development from anthesis and comparativerates of tissue formation established between the species. Themain observation was the slow rate of morphogenesis of embryosand seeds in Lupinus albus in comparison with the very rapidrate observed in Pisum sativum. A long period at the globularembryo stage, when embryo morphogenesis was inactive contributedto the extended development time of embryos and seeds in Lupinusalbus. Slow differentiation of reproductive tissues in L. albusdetermines late maturity in seeds and pods. Lupinus albus, white lupin, L. mutabilis, tarwi, Vicia faba, faba bean, Pisum sativum, pea, Lathyrus latifolius, everlasting pea, embryo development     

Functional Significance of Acid Phosphatase Distribution During Embryo Development in Pisum sativum L

The distribution of P₁, ester P and acid-insoluble nucleic acidP has been studied in relation to acid phosphatase activity(EC 3. 1. 3. 2) in the component parts of developing pea seeds(Pisum sativum L.). Despite the favourable pH of the liquidcontents of the embryo sac (pH 5.5), only very low acid phosphataseactivity was detected in this fluid (c. 0.01 units per seed).Potential substrates for phosphatase action were in fact absentfrom the secretion, the only form of P present being P_i, inconcentrations up to 8 mM. The data support the hypothesis thatthe high acid phosphatase activities which develop in the seed-coatsare involved in regulating the supply of P as P₁ to the developingembryo. Pisum sativum L., pea, embryo development, acid phosphatase, phosphorus, seed-coats, seed development     

A Comparison of the Rate of Maintenance Respiration in Some Crop Legumes and Tobacco Determined by Three Methods

Carbon exchange was measured on whole plants of field bean,lucerne, chick pea, kidney bean, pea and tobacco. The maintenance respiration rate was measured in three ways:(i) by allowing the CO₂ efflux to decay in prolonged darknessto an asymptotic value which was then taken to be the maintenancevalue (the dark decay method); (ii) by plotting the dark CO₂efflux as a function of the net CO₂ uptake over a range of irradiancesand taking maintenance as the dark CO₂ efflux when the net CO₂uptake was zero (the dynamic method); and (iii) by plottingthe total CO₂ uptake as a function of the growth rate and takingmaintenance respiration as the CO₂ efflux when the growth ratewas zero (the zero growth rate method). The range of valuesfor the maintenance coefficient over all species was from 1.6to 2.1 per cent of the dry weight per day, 1.8 to 2.1 per centand 2.7 to 2.9 per cent as determined by these three methodsrespectively. There was a linear relationship, common to allspecies, between the maintenance respiration rate (dark decaymethod) and dry weight, total nitrogen and the organic nitrogencontent. The growth coefficient (0.69±0.01) was the samefor field bean, chick pea and lucerne and was unaffected bythe method of estimation. It was concluded that the dark decay method provided the bestestimate of the minimal maintenance requirements in the plantsstudied. Vicia faba L., Medicago sativa L., Cicer arientinum L., Phaseolus vulgaris L., Pisum sativum L., Nicotiana tobacum L., field bean, lucerne, chick pea, kidney bean, pea, tobacco, respiration, maintenance, growth, nitrogen content     

Stimulation of Adventitious Rooting in Cuttings of Four Herbaceous Species by Piperazine

Piperazine, a chemical used as buffer component, greatly promotedadventitious root formation in cuttings of sunflower (Helianthusannuus L.), pea (Pisum sativum L.), mung bean (Vigna radiataL.) and to a lesser extent in bean (Phaseolus vulgaris L.) seedlings.Piperazine was more effective in acidic pH. The studies withpiperazine analogues showed that any substantial modificationof the structure caused the chemical to be less effective, oreven inhibitory. Histological studies in sunflower hypocotylsdemonstrated that piperazine did not alter the timing of theinitial cell division. In the presence of piperazine, sunflowerhypocotyls failed to develop primary phloem fibres. Piperazineat the concentrations that promote rooting did not kill or damagethe tissue at the base of the hypocotyl. Compared to controls,piperazine treatment did not alter the proportion of primordiathat eventually developed into actively elongating roots. Sixdays after treatment 45% of the control roots in the basal sectionwere actively growing, compared to 51% in the piperazine. Therewas little evidence suggesting that the piperazine-induced promotionof rooting was caused by the removal of basal dominance in whichpiperazine killed the basal part of hypocotyl.Copyright 1995,1999 Academic Press Helianthus annuus, Phaseolus vulgaris, Pisum sativum, Vigna radiata, adventitious roots, mung bean, pea, piperazine, sunflower     

Valeur trophique des acides aminés dans les graines de légumineuses et développement larvaire de Callosobruchus maculatus

Interspecific variation of protein amino acids between peanut, horse bean, french bean, lentil, cowpea and chick-pea was undertaken in relation to larval development of C. maculatus. Twenty-one groups of amino acids were identified and quantified. In all seeds, free amino acids exist in low quantities; but they are more numerous than bound amino acids. Essential amino acids for man are sufficient in the six species, except for the sulphur amino acids in all seeds, and for lysine in peanut. Utilization of those pulses, after cooking, in human food complements cereals. Larval development possibilities of C. maculatus upon the used seeds shows up that: (a) with chick-pea and cowpea, the bruchid thrives normally. However, although amino acids are higher in cowpea than in chick-pea, the better performances were observed on the latter; (b) peanut, french bean, horse bean and lentil are unsuitable for larval development of the insect. Although they are rich in amino acids, all larvae die at first in star within these pulses. We conclude that larval development of C. maculatus does not depend only on the amounts of amino acids in the seeds but also on other trophic factors. These could consist of the balance between different nutritive compounds and the presence of allelochemical substances in the tested seeds which bruchid larvae are unable to utilize.     

Endogenous cis,trans-Abscisic Acid and Pea Seed Development: Evidence for a Role in Seed Growth from Changes Induced by Temperature

Measurements were made using GC/MS SIM¹ of the effects of temperatureon cis,trans-ABA levels in developing ovules and embryos oftwo pea genotypes contrasted in seed size. These effects werethen related to differences in the growth of the pods, seeds,embryos, and testae. In both genotypes high temperatures hastenedthe onset and rate of logarithmic and then linear growth, greatlyshortening the duration of pod and seed development but withoutgreatly altering seed size. Cis,trans-ABA was most concentratedxin the ovules immediately after fertilization. It also accumulatedin the embryo, more rapidly in the larger-seeded line, duringseed maturation. The stage when accumulation in the embryo beganwas the same irrespective of temperature. Accumulation ceasedwhen the pods started to desiccate. The effects of differentconstant temperatures on the maximum levels of embryo cis,trans-ABAwere relatively small and confounded in one genotype by variationin ovule abortion and in the other by differences in the stagewhen cis,trans-ABA accumulation ceased. However, when plantswere transferred from 13 °C to 29 °C at two differentstages during seed maturation, further seed growth was greatlyinhibited coincident with a substantial increase in embryo cis-trans-ABA.The results suggested a role for cis,trans-ABA in the controlof cotyledon enlargement during the linear phase of seed growth.     

Characteristics of Sugar, Amino Acid and Phosphate Release from the Seed Coat of Developing Seeds of Vicia faba and Pisum sativum

After removal of the embryo from developing seeds of Vicia fabaL. and Pisum sativum L., the ‘empty’ ovules werefilled with a standard solution (pH 5.5). Seed coat exudatesof both species were collected during relatively long experiments(up to about 12 h) and the concentration of sugar (mainly sucrose),amino acids and phosphate in the exudate measured. A discussionis presented on the amino acid/sugar ratio and the phosphate/sugarratio in the seed coat exudate. A pretreatment (15 min) withp-chloromercuribenzenesulphonic acid (PCMBS) reduced the releaseof sugar, amino acids and phosphate from broad bean seed coats.After excision of ‘empty’ ovules of Vicia faba andPisum sativum from the maternal plant, 2–4 h after thistreatment a strong difference became visible between sucroserelease from excised seed coats and sucrose release from attachedseed coats. Similarly, when the rate of phloem transport ofsucrose into an ‘empty’ ovule of Vicia faba or Pisumsativum was reduced by a sub-optimal mannitol concentrationin the solution, a reduced rate of sugar release from the seedcoat could be observed. Excision and treatment with a sub-optimalmannitol concentration reduced the release of amino acids toa lesser extent than for sucrose. These treatments did not reducethe rate of phosphate release from the seed coat. Key words: Seed development, Seed coat exudate, Phloem transport     

Stimulation of ethylene production by hydroxamic acid, in particular, by benzohydroxamic acid

The effects on the ethylene production of known inhibitors ofa cyanide-insensitive, alternative respiration in plants wereinvestigated using cotyledonary segments of cocklebur (Xanthiumpennsylvanicum Wallr.) seeds. Benzohydroxamic acid (BHAM) at3 mM stimulated ethylene production 4- to 8-fold over the control,but respiration of the segments was hardly affected at thatconcentration. The stimulatory effects of 3-chlorobenzohydroxamicacid (CLAM) and salicylhydroxamic acid were far smaller thanthat of BHAM. BHAM at 3 mM also markedly stimulated the ethyleneformation in the epicotyl or hypocotyl sections of etiolatedpea (Pisum sativum L.) and mung bean (Vigna radiata [L.] Wilczek)seedlings. Moreover, 3 mM BHAM further promoted the increasedethylene formation which was caused by administration of 1-aminocyclopro-pane-1-carboxylicacid (ACC) to the cotyledonary segments. The promoting effectsby BHAM and CLAM were also found in the conversion of ACC intoethylene in pea stem homogenates. (Received July 26, 1980; )     

Feeding preferences and related types of behaviour of Neomegalotomus parvus

Laboratory studies with Neomegalotomus parvus(Westwood) (Hemiptera: Alydidae) with one nymph per Petri dish in multiple-choice tests indicated that seeds of pigeon pea [Cajanus cajan(L.) Mills.], lablab (Dolichos lablabL.), and soybean [Glycine max(L.) Merrill] were visited before seeds of common bean (Phaseolus vulgarisL.) and rice (Oryza sativaL.). The percentage of individuals engaging in dabbing/antennation resulting in probing, and percentage probing resulting in feeding, were higher on common bean (97%) and pigeon pea (87%) seeds than on lablab (55%), soybean (50%), or rice (5%) seeds. No significant differences were found in preference (number of flanges) among pigeon pea, common bean, and lablab, and preference (insects on foods) varied throughout the assessment period (5 d). In tests using 10 nymphs per dish, pigeon pea was the preferred food (number of flanges and insects on plants) throughout the period (5 d). In no-choice tests, the average duration of a feeding session and the longest feeding session were greater on lablab and common bean than on pigeon pea, soybean, or rice seeds. The number of feeding sessions was greater on seeds of common bean, pigeon pea, and soybean than on those of lablab or rice. Laboratory tests with N. parvusadults indicated that pigeon pea seeds were located faster, followed by common bean, soybean, and rice. When pods were tested, dabbing/antennation time was shorter on pigeon pea than on soybean, and probing time was longer on soybean than on pigeon pea or common bean. On pigeon pea, 100% of the insects probed the host, while on common bean and soybean pods, and on rice panicles, these values dropped to 71.8%, 46.0%, and 10.5%, respectively. Adults showed similar feeding times on pigeon pea, common bean, and soybean pods, but did not feed on rice panicles. Electronmicroscopical analysis showed the presence of two apical lobes with 12 peg sensilla on the labial tip. Sensillum tips were stained with silver nitrate solution, indicating a permeability of the cuticle and, therefore, their function as taste receptors.