Development of Lateral Root Primordia in Vicia faba, Pisum sativum, Zea mays andPhaseolus vulgaris: Rates of Primordium Formation and Cell Doubling Times

Lateral root primordium development has been examined in primaryroots of Vicia faba L., Pisum sativum L., Zea mays L. and Phaseolusvulgaris L. Following their initiation from an estimated minimumnumber of 77–162, 20–57, 17 and 12 cells respectivelyin Vicia, Phaseolus, Pisum and Zea, the primordia rapidly increasedin cell number to emerge as secondary roots about 2.8–3.6days later depending on the species being examined. Cell doublingtimes were estimated directly from cell numbers at differenttimes following primordium inception and were found to increasewith increase in primordium size in each of the species investigated. The number of primordia formed per cm of root growth per daywas greatest in Zea and least in Pisum. A comparison of thedata obtained for Vicia with that in the literature led to theconclusion that although the number of primordia produced percm of root growth was independent of the rate of primary elongation,the number produced per day increased in a linear fashion withincrease in the rate at which the primary lengthened. Vicia faba L, Pisum sativum L, Zea mays L, Phaseolus vulgaris L, broad bean, garden pea, maize, dwarf bean, root primordia, cell division, cell doubling time     

Some Effects of Sucrose Concentration on Primordium Development in Excised Primary Roots

The effects of varying the amount of sucrose used to supplementthe culture medium maintaining the growth of excised roots ofPisum sativum L., Vicia faba L., Zea mays L. and Phaseolus vulgarisL., on the rates of primordium initiation and subsequent emergenceas lateral roots and on the duration of the interval betweenprimordium inception and emergence as a secondary root throughthe tissues of the primary have been investigated. Variation in the exogenous concentration of sucrose from 0.5to 8 per cent had little effect on the rate of primordium inceptionin Pisum and Vicia and the rates never reached the values obtainedfor the roots of the corresponding intact plants. Moreover,over the 6 day culture period lateral root emergence did notoccur in any of the excised roots of these two species. In contrast,each of the aspects of primordium development examined in theexcised roots of Zea and Phaseolus was markedly affected bythe amount of sucrose used to supplement the culture medium.In addition, in the presence of about 6 per cent sucrose, primordiumdevelopment in these cultured roots was very similar to thatin roots of the corresponding intact plants. The results indicate either that some factor necessary for primordiumdevelopment is present in adequate amounts in excised rootsof Zea and Phaseolus, but not in those of Pisum and Vicia, orthat the factors controlling such development are differentin the former and latter two species. Vicia faba L., Pisum sativum L., Zea mays L., Phaseolus vulgaris L., broad bean, garden pea, maize, dwarf bean, primordium development, sucrose concentration, cultured roots     

Lateral Root Anlage Development in Excised Roots of Vicia faba L., Pisum sativum L., Zea mays L. and Phaseolus vulgaris L.

The development of lateral root primordia has been investigatedin excised roots of Vicia faba, Pisum sativum, Zea mays andPhaseolus vulgaris cultured in White's medium supplemented with2 per cent sucrose and compared with previously published dataon such development in primaries of the corresponding intactplants (control roots). Primordia were produced in each batchof excised roots over the 6 day culture period but at a lowerrate (number day^–1) than in the controls. Such primordia in cultured roots of Zea and Phaseolus completedtheir development and grew out as lateral roots over a periodsimilar in length to that found in the controls, but with acell number of only about 33 per cent of that attained at thetime of secondary emergence in the primaries of the latter roots.These lower cell numbers were at least partly a reflection ofincreases in mean cell doubling time over the period of anlagedevelopment investigated in the excised roots relative to thecorresponding values found in the controls. Primordia initiated in excised roots of Pisum and Vicia didnot complete their development in culture, i.e. no lateral rootsemerged and arrest took place with cell numbers of only 37 (Pisum)and 17 (Vicia) per cent of the numbers determined at the timeof secondary root emergence in the controls. Such arrested primordiahad few nuclei in S and none in mitosis. Moreover, at leastin Pisum, the frequency distribution of the relative DNA contentof the nuclei in the latter primordia approximated that foundin the apical meristem of primary roots following the establishmentof the stationary phase under conditions of carbohydrate starvation. It has also been demonstrated in the course of these investigationsthat lateral root primordium development in all four speciesis at least biphasic and possibly triphasic. Vicia faba L., broad bean, Pisum sativum L., garden pea, Zea mays L., maize, Phaseolus vulgaris L., dwarf bean, root primordia, anlage, cell doubling time, lateral root emergence     

Determination of Stelar Elements in Roots of Pisum sativum L.

Cytochemical studies of esterase activity in 0.5 mm segmentsfrom root tips of Pisum sativum explanted for up to 9 days inbasal culture medium containing 2 per cent sucrose showed retentionof this activity. During this time, all segments from the secondand third 0.5 mm segments of the root tip developed xylem elementsas did the proximal end of the first segment. No xylem elementswere found in the 12–14 cells behind the quiescent centre.It is concluded that the central group of meristem cells aregenerally programmed to form tissues of the stele immediatelyon leaving the quiescent centre, and that the programming forxylem and phloem elements occurs as a second step. Pisum sativum L., garden pea, determination, histochemistry, esterases, stele, root     

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     

An Early Cytochemical Marker of Commitment to Stelar Differentiation in Meristems from Dicotyledonous Plants

A cytochemical study of root apices from Vicia faba and Pisumsativum showed esterase activity to be present in the stele,root cap and rhizodermis, but almost completely absent fromthe developing cortex and quiescent centres. The meristem cellsgiving rise to the cortex were almost negative whilst thosegiving rise to the stele were positive for esterase activity.Cambia from roots, shoots and petioles of a number of dicotyledonousspecies were all positive for esterase activity. It is proposedthat esterase activity may be used as an early marker of commitmentto differentiation into stele in roots of dicotyledonous plants,and that the cambia are fully committed meristems. Pisum sativum L., Vicia fabaL., garden pea, broad bean, meristems, stelar differentiation, esterase activity, xylem differentiation, cytochemistry, cambium     

Chromosome Aberrations and Ageing Root Meristems

Changes in mitotic activity and frequency of spontaneous chromosomeaberrations have been determined for primary roots of Zea muys,Pisum sativum, Vicia faba var. green Windsor and var. minor,and Allium cepa. Mitotic activity was found to decline withage in all root apices. In the primary root apices immediately after germination, therewas a high frequency of spontaneous chromosome aberrations whichdeclined with time after germination. However, In the case ofV. faba var. green Windsor, Z mays and P. sativum there wasa return to the high levels of spontaneous chromosome aberrationon ageing of the root apex. root meristems, mitotic activity, chromosome aberrations, ageing     

Stomata on the Primary Root of Pisum sativum L.

The first record of stomata on a non-specialized root was obtainedby scanning electron microscopy of 4-d-old Pisum sativum L.In some cases subsidiary cells were trichoblasts. Stomata andthe root triarch vascular structure were simultaneously presentin transverse sections through the root. Pisum sativum, pea, root stomata, guard cells, trichoblasts     

Some Effects of Indol-3-yl Acetic Acid on Lateral Root Development in Attached and Excised Roots of Pisum sativum L.

The effect of continuous exposure to indol-3-yl acetic acid(IAA) on primordium initiation and their subsequent emergenceas lateral roots was determined in excised and attached rootsof Pisum sativum. IAA was found to stimulate the number of primordiainitiated per centimetre of attached or excised primary. Similarly,lateral emergence in terms of the number produced per centimetreof primary was promoted in the presence of IAA. This stimulationof lateral emergence even took place in excised roots whichwere 1 cm in length at the onset of culture and which neverproduced secondary roots over a 6-d culture period when grownin the absence of auxin. These effects of IAA on lateral rootdevelopment have been considered in relation to the concurrentchanges which take place in proliferative activity in the apicalmeristem of the primary root during exposure to auxin. Pisum sativum, garden pea, anlage, primordium, emerged lateral, cell proliferation, indol-3-yl acetic acid     

Abscisic Acid Accumulation by in Situ and Isolated Guard Cells of Pisum sativum L. and Vicia faba L. in Relation to Water Stress

Isolated guard cells, prepared by sonication of epidermal peels, were used to investigate the endogenous level of abscisic acid (ABA) in the guard cells of turgid and stressed leaves of Vicia faba L. and the argenteum (arg) mutant of Pisum sativum L. The guard cells of V. faba and arg were found to contain 18 and 8 times more ABA, respectively, when isolated from stressed leaves than from turgid leaves. Isolated guard cells of V. faba were also directly stressed with the osmoticum Aquacide III. These guard cells were capable of producing stress-induced ABA to at least 3 times their ABA level when non-stressed.     

A Microautoradiographic Study of Auxin Transport in the Stem of Intact Pea Seedlings (Pisum sativum L.)

Soluble-compound microautoradiography was used to determinethe distribution of radioactivity in transverse sections ofintact dwarf pea stems (Pisum sativum L.) following the applicationof [³H]IAA to the apical bud. Near the transport front labelwas confined to the cambial zone of the axial bundles, includingthe differentiating secondary vascular elements. Fully differentiatedphloem and xylem elements remained unlabelled and no radioactivitywas detected in the leaf or stipule traces. Similar resultswere obtained in experiments with Vicia faba L. plants. Nearerthe labelled apical bud of the pea there was a more generaldistribution of label and evidence was found of free-space transportof radioactive material in the pith. When [³H]IAA was applied to mature foliage leaves the greatestconcentration of label was found in the differentiated phloemelements of the appropriate leaf trace and in the phloem ofthe adjacent axial bundles. Both basipetal and acropetal transportwas detected in this case. These results are consistent with the conclusions drawn fromearlier transport experiments which indicated that in the intactplant the long-distance basipetal transport of auxin from theapical bud takes place in a system which is separated from thephloem transport system and suggests that the vascular cambiumand its immediate derivatives may function as the normal pathwayfor the longdistance movement of auxin in the plant. The physiologicalsignificance of such a transport system for auxin is discussed.     

Effect of the Osmotic Environment on K+ and Mg2+ Release from the Seed Coat and Cotyledons of Developing Seeds of Vicia faba and Pisum sativum. Evidence for a Stimulation of Efflux from the Vacuole at High Cell Turgor

After removal of the embryo from developing seeds of Vicia fabaL. and Pisum sativum L., the ‘empty’ ovules werefilled with a substitute medium (pH 5.5) and the effect of theosmolality of the medium on K⁺ and Mg²⁺ release from the seedcoat was examined. In long-term experiments (12 h or longer),with both attached and detached seed coats, the rate of K⁺ andMg²⁺ release from seed coats filled with a solution withoutosmoticum was enhanced, in comparison with release from seedcoats filled with a solution containing 400 mol m     

Buckminsterfullerene (C-60 Carbon Allotrope) Inhibits Ethylene Evolution from 1-Aminocyclopropane-1-carboxylic acid (ACC)-treated Shoots of Pea (Pisum sativum), Broadbean (Vicia faba) and Flowers of Carnation (Dianthus caryophyllus)

When applied either in the form of a colloidal solution or inliposomes, buckyballs (C-60—buckminsterfullerene) markedlyreduced ethylene evolution from cut carnation (Dianthus caryophyllus)flowers, as well as pea (Pisum sativum) and broadbean (Viciafaba) foliage treated with ethylene precursor l-aminocyclopropane-l-carboxylicacid (ACC). The liposome preparation was approximately twiceas effective as colloidal solutions. Moreover, upon being incubatedin a closed atmosphere with ethylene, buckyballs induced a significantdepletion of ambient ethylene which was temperature and C-60—concentrationdependent. This mode of C-60 action is attributed to ethyleneadsorption stemming from the vast C-60 surface area, calculatedto be 1317 m² g_-1, and the affinity of its carbon atoms forthe component in the ethylene double bond.Copyright 1993, 1999Academic Press Dainthus caryophyllus, Pisum sativum, Vicia faba, adsorption, ethylene, fullerene     

Cortical Cell Breakdown and Lateral Root Primordium Development in Vicia faba L

The effect of the formation of a cavity in the cortex of theprimary root of Vicia faba adjacent to lateral root primordiaon root development has been investigated. Premature exposureof such primordia to the external medium by removing the overlyingtissues of the primary root has no effect on primordium developmentif that primordium was within 48 h of emerging as a lateralroot. Similar exposure of primordia which were at an earlierstage of development and consisted of between 3400 and 7000cells resulted in the generation of a stationary phase, withmost of the nuclei arrested in G1 (presynthetic interphase),48–72 h after exposure began, followed by nuclear degenerationby 96 h. Since no mature vascular tissue was found in theseprimordia until after they emerged as secondary roots, all ofthe nutrients necessary for the maintenance of cell proliferationin these meristems must reach them by simple diffusion fromthe surrounding medium. A preliminary analysis of the liquidcontents of the cavity next to developing primordia demonstratesit to be rich in carbohydrates and it is clear, from the resultsreported in this paper, that cell proliferation in primordia,consisting of a mean number of 5400 cells, is largely dependenton the substances present in the cavity fluid, although somematerials reach the primordium by diffusion from the cells ofthe primary root to which the primordium remains attached.     

15. Karl Rippel: Wachstumshemmende Wirkstoffe oder gebundene (inaktivierte) Wuchsstoffe?

Der wäßrige Extrakt aus den Kotyledonen von Vicia faba und dem frischen Sproß von Pisum sativum enthält Wirkstoffe, die auf bestimmte Rassen von Saccharomyces cerevisiae wachstumshemmend wirken.     

Use of the Expolinear Growth Model to Analyse the Growth of Faba bean, Peas and Lentils at Three Densities: Fitting the Model

The expolinear equation for crop growth (Goudriaan and MonteithAnnalsof Botany66: 695–701, 1990) was fitted to measurementsof above ground dry weight made on two cultivars of each ofthree species, faba bean (Vicia fabaL.), peas (Pisum sativumL.)and lentils (Lens culinarsMedic.), each grown at three densitiesat the University of Reading, UK in 1992 and 1993. The expolinearequation fitted the data well but required frequent samplingto obtain good estimates of the parameters. The equation hasthree parameters,R_mthe maximum relative growth rate,C_ma maximumcrop growth rate, andt_bthe time at which the crop effectivelyreaches a linear phase of growth.R_mdid not differ between densities,cultivars or species but differed between years.C_mincreasedwith increased density and was lower for lentils than for fababeans or peas.t_bdecreased with increased density for faba beanbut not for the other species. Incorporating an extinction coefficientfor solar radiation and the maximum fraction of radiation interceptedenabled reasonably accurate time courses of leaf area indexto be derived, as suggested by Goudriaan (1994. In: MontiethJL, Scott RK, Unsworth MH, eds.Resource capture by crops. Nottingham:Nottingham University Press, 99–110).Copyright 1998 Annalsof Botany Company Expolinear equation, grain legumes, crop growth rate, crop density, relative growth rate, growth modelling, faba bean,Vicia fabaL., peas,Pisum sativumL., lentils,Lens culinarsMedic.     

Structural basis for the affinity of four insolubilized lectins,with a specificity for α-D-mannose,towards various glycopeptides with the N-glycosylamine linkage and related oligosaccharides

Precisions are given on the fine specificity and on the usefulness of immobilized concanavalin A,Lens culinaris, Vicia faba andPisum sativum agglutinins for fractionation of glycopeptides with the N-glycosylamine linkage.While insolubilized concanavalin A represents a very useful tool for the fractionation of both N-acetyllactosaminic and oligomannosidic type glycopeptides or related oligo-saccharides, immobilizedLens culinaris, as well asVicia faba orPisum sativum agglutinins allow the subfractionation of some N-acetyllactosaminic glycopeptide populations on the basis of the presence of an α-L-fucose residue substituting in C-6 position the N-acetylglucosamine residue involved in the N-glycosylamine bond.     

Exogenous Auxin Effects on Lateral Bud Outgrowth in Decapitated Shoots

In 1933 Thimann and Skoog demonstrated exogenous auxin repressionof lateral bud outgrowth in decapitated shoots ofVicia faba. This evidence has given strong support for a role of auxinin apical dominance. Most, but not all, investigators have confirmedThimann and Skoog's results. In the present study, auxin treatmentswere carried out on ten different species or plant types, manyof which were treated with auxin in different forms, media andunder different light conditions. The Thimann–Skoog experimentdid work for most species (i.e. exogenous auxin did repressbud outgrowth) including thedgt tomato mutant which is knownto be insensitive to auxin in certain responses. Toxic auxinsymptoms were observed in some but not all species. The Thimann–Skoogexperiment did not work for greenhouse-grownColeus or forArabidopsis. Light was shown to reduce apical dominance inColeus andIpomoeanil . apical dominance; lateral bud outgrowth; axillary bud; auxin; IAA; decapitation; Vicia faba ; Ipomoea nil ; Pisum sativum ; Phaseolus vulgaris ; Lycopersion exculentum ; dgt ; Coleus blumei ; Arabidopsis thaliana ; Helianthus annuus ; Thimann–Skoog     

Changes in Poparity of Growth During Leaf Initiation in the Pea, Pisum sativum L.

In the apical dome of the pea shoot apex the axis of growthof the epidermal cells becomes predominantly longitudinal inthe I₁ region one plastochron before a leaf is initiated, andthis orientation persists into the young primordium. In contrast,in the underlying, non-epidermal cells the growth axis in theI₁ region becomes randomized half a plastochron before leafinitiation, but in the young primordium it becomes the sameas in the epidermis. The initiation of a leaf primordium thereforetakes place without any major change in the orientation of growthaxes in the epidermis. A controlling role for the epidermisis therefore suggested. No marked reorientation of the growthaxis occurs on the sides of the newly initiated primordium.The shape of the young primordium can be related to the differentialrates of growth and division within it rather than to changesin growth orientation. Pisum sativum, pea, shoot apex, meristem, growth, epidermis, polarity     

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