Floral development and vascularization help to explain merism evolution inPaepalanthus(Eriocaulaceae, Poales)

BackgroundFlowers in Eriocaulaceae, a monocot family that is highly diversified in Brazil, are generally trimerous, but dimerous flowers occur inPaepalanthusand a few other genera. The floral merism in an evolutionary context, however, is unclear.Paepalanthusencompasses significant morphological variation leading to a still unresolved infrageneric classification. Ontogenetic comparative studies of infrageneric groups inPaepalanthusand in Eriocaulaceae are lacking, albeit necessary to establish evolution of characters such as floral merism and their role as putative synapomorphies.MethodsWe studied the floral development and vascularization of eight species ofPaepalanthusthat belong to distinct clades in which dimery occurs, using light and scanning electron microscopies.ResultsFloral ontogeny in dimerousPaepalanthusshows lateral sepals emerging simultaneously and late-developing petals. The outer whorl of stamens is absent in all flowers examined here. The inner whorl of stamens becomes functional in staminate flowers and is reduced to staminodes in the pistillate ones. In pistillate flowers, vascular bundles reach the staminodes. Ovary vascularization shows ventral bundles in a commissural position reaching the synascidiate portion of the carpels. Three gynoecial patterns are described for the studied species: (1) gynoecium with a short style, two nectariferous branches and two long stigmatic branches, in most species; (2) gynoecium with a long style, two nectariferous branches and two short stigmatic branches, inP. echinoides; and (3) gynoecium with long style, absent nectariferous branches and two short stigmatic branches, inP. scleranthus.DiscussionFloral development of the studied species corroborates the hypothesis that the sepals of dimerous flowers ofPaepalanthuscorrespond to the lateral sepals of trimerous flowers. The position and vascularization of floral parts also show that, during dimery evolution inPaepalanthus, a flower sector comprising the adaxial median sepal, a lateral petal, a lateral stamen and the adaxial median carpel was lost. In the staminate flower, the outer whorl of staminodes, previously reported by different authors, is correctly described as the apical portion of the petals and the pistillodes are reinterpreted as carpellodes. The occurrence of fused stigmatic branches and protected nectariferous carpellodes substantiates a close relationship betweenP.sect.ConodiscusandP.subg.Thelxinoë. Free stigmatic branches and exposed carpellodes substantiate a close relationship betweenP. sect.Diphyomene,P. sect.EriocaulopsisandP. ser.Dimeri. Furthermore, the loss of nectariferous branches may have occurred later than the fusion of stigmatic branches in the clade that groupsP. subg.ThelxinoëandP. sect.Conodiscus.

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The floral development of Monococcus echinophorus (Phytolaccaceae)

Canadian Journal of Botany ◽

10.1139/b97-906 ◽

1997 ◽

Vol 75 (11) ◽

pp. 1941-1950 ◽

Cited By ~ 4

Author(s):

P. F. Vanvinckenroye ◽

L. P. Ronse Decraene ◽

E. F. Smets

Keyword(s):

Electron Microscope ◽

Floral Development ◽

Variable Number ◽

Monotypic Genus ◽

Floral Ontogeny ◽

Short Style ◽

Close Relationship ◽

Median Position ◽

Relationship Of ◽

Scanning Electron

The floral ontogeny of the monotypic genus Monococcus (Phytolaccaceae) is investigated with the scanning electron microscope. Flowers arise on pendent racemes and are preceded by a bract and two bracteoles arising successively. In both staminate and pistillate flowers four sepals are incepted in diagonal position. In the staminate flowers four alternisepalous stamens are initiated successively. Further stamen inception occurs centrifugally and runs concomitant with peripheral growth of the receptacle. This centrifugal stamen initiation is interpreted phylogenetically as a secondary increase and is expressed by the appearance of four triplets. Initiation of a variable number of outermost stamens (0–8) occurs mostly in the latero-abaxial region of the flower. In staminate flowers there is no trace of a gynoecium. In pistillate flowers a gynoecium primordium arises centrally and grows into a monocarpellate structure. Later, hooked bristles arise on the carpel flanks while a short style is produced bearing a distal tangle of long hairs. A close relationship of Monococcus with Petiveria is confirmed; similarities include the median position of the prophylls, the diagonal position of four sepals, the sequential inception of four alternisepalous stamens, and the fruits with adaptations for exozoochory. Key words: androecium, floral ontogeny, Monococcus, Phytolaccaceae, Rivinoideae.

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Floral development of Zannichellia palustris

Canadian Journal of Botany ◽

10.1139/b76-068 ◽

1976 ◽

Vol 54 (8) ◽

pp. 651-662 ◽

Cited By ~ 21

Author(s):

U. Posluszny ◽

R. Sattler

Keyword(s):

Floral Development ◽

Staminate Flower ◽

Pistillate Flower ◽

Bisexual Flower ◽

The Third ◽

Short Style ◽

Procambial Strand ◽

The One ◽

The Right ◽

Floral Bud

What, at maturity, appears to be a bisexual flower in the axil of one of two subopposite leaves, is revealed as a fertile nodal complex with quite different organization. Three appendages develop at each nodal complex. The first girdles the stem and becomes at maturity a membranous sheath about the entire node. The second subtends the axillary meristem, which terminates as the staminate flower, and branches laterally as a renewal growth in the axil of a sterile appendage just below the stamen. The third appendage is subopposite the terminal meristem, which gives rise to the pistillate floral bud towards the staminate flower, and a renewal growth apex towards the appendage. This renewal growth apex repeats the entire pattern at almost a 90° shift to the right or left, depending on the shoot. The single stamen of the staminate flower develops as those studied in Potamogeton and Ruppia. The pistillate flower develops two carpel primordia, which become peltate before initiating a single ovule primordium on the adaxial portion (Querzone). The membranous envelope which covers the carpels at maturity is initiated at ovule inception, below one of the carpels. A peltate stigma differentiates on a short style and at maturity becomes broad and lobed. The renewal growth apex has a one-layered tunica. The membranous sheaths of the node and of the pistillate flower are primarily protodermal in origin, while the rest of the sterile and reproductive appendages arise through activity in subprotodermal cells. Procambial development is acropetal closely following primordial inception. Each organ (sterile or fertile) receives one procambial strand, except for the membranous sheath about the node and the one about the pistillate flower.

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Floral development of Najas flexilis

Canadian Journal of Botany ◽

10.1139/b76-123 ◽

1976 ◽

Vol 54 (10) ◽

pp. 1140-1151 ◽

Cited By ~ 16

Author(s):

U. Posluszny ◽

R. Sattler

Keyword(s):

Floral Development ◽

Staminate Flower ◽

Pistillate Flower ◽

Axillary Meristem ◽

Short Style ◽

Najas Flexilis ◽

Floral Apex ◽

Cell Layers ◽

The One ◽

Floral Bud

Two subopposite leaves form at a node. The lower one arises almost simultaneously with the axillary meristem which it subtends. The upper leaf initiates after the lower one and does not subtend any structure. The axillary meristem gives rise to a renewal growth apex and a floral bud almost at its inception. In some cases the axillary meristem forms only a floral bud. The floral bud may be either staminate or pistillate. The main axis and the renewal growth in the axil of the lower leaf repeat this pattern of development. Staminate and pistillate flowers are almost indistinguishable at inception. They form as dome-like protuberances and both initiate girdling primordia, which become lobed at or immediately after inception. In the staminate flower the girdling primordium becomes the outer envelope, while a second girdling primordium formed acropetally becomes the inner envelope. Both envelopes overgrow the one-celled anther, which is the transformed staminate floral apex. In the pistillate flower the girdling primordium becomes the gynoecial wall that encloses the single bitegmic ovule, which is the transformed pistillate floral apex. On a short style a stigma with two to four branches develops. The renewal growth apices have a one-layered tunica. The two subopposite leaves are initiated through cell division in both tunica and corpus cells. The axillary meristem arises through periclinal divisions in the corpus cells. The girdling primordia of both staminate and pistillate floral buds are epidermal in origin as are the integuments of the ovule. Procambial development is acropetal following closely primordia inception. Each leaf, floral bud, and renewal growth apex receives a single strand. No vascularization is seen in envelopes of the staminate flower or the gynoecial wall of the pistillate flower, all of which remain two cell layers thick even at maturity.

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Can the anatomy of abnormal flowers elucidate relationships of the androecial members in the ginger (Zingiberaceae)?

10.21203/rs.2.14711/v1 ◽

2019 ◽

Author(s):

Li Xiumei ◽

Fan Tian ◽

Zou Pu ◽

Zhang Wenhu ◽

Wu Xiuju ◽

...

Keyword(s):

Vascular System ◽

Staminate Flower ◽

Vascular Supply ◽

Vascular Bundles ◽

Ancestral State ◽

Serial Sections ◽

Floral Structure ◽

State Reconstruction ◽

Outer Whorl ◽

Different Types

Abstract Background Interpretation of the floral structure of Zingiberaceae has long concentrated on the relationships of the androecial members. It has been suggested that the labellum is composed of two structures rather than three or five, and the glands are not only the epidermis of the ovary but are similar to nectaries. Results Serial sections were used to observe the vasculature of normal and two-staminate flowers in Alpinia intermedia ‘shengzhen’. Floral diagrams were drawn to interpret the morphological category of the floral organs and the relationships of the androecial members. Androecial vascular bundles were associated with carpellary dorsal bundles (CDBs) and parietal bundles (PBs) in a Zingiberales phylogeny setting using ancestral state reconstruction. Anatomical observations demonstrate that the fertile stamen(s) incorporate parietal strands both in normal and two-staminate flowers. The three appendages represent the three members of the outer whorl of the androecium while the labellum represents the inner whorl of the androecium in the two-staminate flower. Reconstruction of the origin of the vascular system in the androecium suggests that the outer whorl of androecium receives its vascular supply from the CDBs and the inner whorl of androecium receives from the PBs in both the basal banana group and the more derived ginger clade. Conclusions The present study adds to a growing body of literature suggesting that anatomy of abnormal flowers may not provide enough evidence for elucidating the relationships of the androecial members. Abnormal flowers are diverse in the Zingiberaceae and may derive from different types of mutations.

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The potential digestibility of cellulose in grasses and its relationship with chemical and anatomical parameters

The Journal of Agricultural Science ◽

10.1017/s0021859600026381 ◽

1972 ◽

Vol 78 (3) ◽

pp. 457-464 ◽

Cited By ~ 13

Author(s):

R. J. Wilkins

Keyword(s):

Floral Development ◽

Lignin Content ◽

Leaf Sheath ◽

Vascular Bundles ◽

Cellulose Digestibility ◽

Wimmera Ryegrass ◽

Rate Of Decline ◽

The Relationship ◽

Anatomical Parameters

SUMMARYPotential cellulose digestibility, measured by incubation in vitrofor 6 days, decreased during floral development in perennial ryegrass, Wimmera ryegrass, cocksfoot, oat and tall fescue. The rate of decline was slower than for cellulose digestibility measured after incubation in vitro for 2 days only. Morphological fractions ranked in order of descending potential cellulose digestibility – leaf blade, inflorescence, leaf sheath and stem.Lignin content was determined chemically by the method of Van Soest (1963) and lignified tissue was assessed by staining transverse sections of leaf blades and leaf sheaths with safranin and fast green. Both lignin and lignified tissue increased with maturity. Lignified tissue increased mainly through increase in the number of scleren-chyma cells, but was also affected by the formation of lacunae or cavities between the vascular bundles in leaf blades of cocksfoot and in leaf sheaths of all species studied. For 19 samples of leaf blades and leaf sheaths, potential cellulose digestibility had significant negative correlations with both lignin content (r = -0·862) and lignified tissue (r = -0·905). Limitations to the techniques used to assess lignification and further factors which may affect the relationship between lignification and potential cellulose digestibility are discussed.

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Extracellular matrix surface network is associated with non-morphogenic calli of Helianthus tuberosus cv. Albik produced from various explants

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2014.009 ◽

2014 ◽

Vol 83 (1) ◽

pp. 67-73 ◽

Cited By ~ 6

Author(s):

Maria Pilarska ◽

Marzena Popielarska-Konieczna ◽

Halina Ślesak ◽

Małgorzata Kozieradzka-Kiszkurno ◽

Grzegorz Góralski ◽

...

Keyword(s):

Extracellular Matrix ◽

In Vitro Regeneration ◽

Vascular Bundles ◽

Helianthus Tuberosus ◽

Important Species ◽

Electron Microscopies ◽

Transmission Electron ◽

Matrix Surface ◽

Surface Network

Helianthus tuberosus is economically important species. To improve characters of this energetic plant via genetic modification, production of callus tissue and plant regeneration are the first steps. A new, potentially energetic cultivar Albik was used in this study to test callus induction and regeneration. Callus was produced on leaves, petioles, apical meristems and stems from field-harvested plants but was totally non-morphogenic. Its induction started in the cortex and vascular bundles as confirmed by histological analysis. The surface of heterogeneous callus was partially covered with a membranous extracellular matrix surface network visible in scanning and transmission electron microscopies. The results clearly indicate that: (i) the morphogenic capacity of callus in topinambur is genotype dependent, (ii) cv. Albik of H. tuberosus proved recalcitrant in in vitro regeneration, and (iii) extracellular matrix surface network is not a morphogenic marker in this cultivar.

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The vegetative and floral development of the hybrid grape cultivar ‘Ventura’

Canadian Journal of Botany ◽

10.1139/b86-218 ◽

1986 ◽

Vol 64 (8) ◽

pp. 1620-1631 ◽

Cited By ~ 18

Author(s):

Usher Posluszny ◽

Jean M. Gerrath

Keyword(s):

Fourth Order ◽

Floral Development ◽

Upper Arm ◽

Grape Cultivar ◽

Stamen Primordia ◽

Short Style

The vegetative and floral development of the hybrid grape cultivar ‘Ventura’ was studied. A tendril forms opposite the last-formed leaf on the shoot but is slightly delayed in its initiation. Six nodes and 10 primordia complete one leaf–tendril initiation cycle. The inflorescence develops at the same site and is initially indistinguishable from the tendril. Inflorescence primordia are initiated on the upper arm, first opposite each other in a decussate arrangement and then apparently spirally. Each inflorescence primordium may subsequently initiate two lateral primordia, which become subtended by bracts. These in turn may repeat the pattern so that ultimately third- or fourth-order cysmose inflorescence branches may be produced. During floral development the calyx is initiated at first as three primordia, followed by a ring, which ultimately develops five lobes. The five corolla primordia alternate with the sepals. The five stamen primordia are initiated opposite the petals. The gynoecium initiates as five primordia, which later become a ring. Two septae are initiated opposite each other on the inner flank of the ring, forming the two-loculed ovary. Each septum forms a placenta, giving rise to two ovules. The upper portion of the gynoecial ring grows up over the ovules and forms the short style and discoid stigma.

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An updated interpretation of the androecium of the Fumariaceae

Canadian Journal of Botany ◽

10.1139/b92-219 ◽

1992 ◽

Vol 70 (9) ◽

pp. 1765-1776 ◽

Cited By ~ 20

Author(s):

L. P. Ronse Decraene ◽

E. F. Smets

Keyword(s):

Key Words ◽

Floral Development ◽

Flower Bud ◽

Stamen Primordia ◽

Outer Whorl ◽

Spatial Median ◽

Median Position

A study of the floral development of Dicentra formosa, Corydalis lutea, and Hypecoum procumbens was carried out to better understand the nature of the androecium in Fumariaceae. Sepals emerge successively in a median position and are followed by two alternating pairs of petals. Four stamen primordia are formed in a diagonal position. They are promptly followed by two lateral, slightly externally inserted primordia. In Dicentra and Corydalis the stamens arise on two crescent-shaped protuberances. In Hypecoum, four diagonal androecial primordia fuse into two median staminal complexes. The gynoecium emerges as a girdling primordium with four growth centers. Different interpretations of the androecium are discussed. It is demonstrated that the androecium in the Fumariaceae consists basically of two whorls: an outer whorl of four alternipetalous stamens and an inner whorl of two lateral stamens superposed to the outer petals. The monothecal nature of the alternipetalous stamens and the fusion of the stamens in two triplets is probably caused by a spatial median compression of the flower bud. The androecium of Hypecoum is the result of interprimordial growth between the pairs of monothecal stamens, and the androecium of Pteridophyllum arises through the loss of the two lateral stamens superposed to the outer petals. Key words: Fumariaceae, floral development, androecium, stamen whorls.

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Functional Analysis of the Phosphate Transporter Gene MtPT6 From Medicago truncatula

Frontiers in Plant Science ◽

10.3389/fpls.2020.620377 ◽

2021 ◽

Vol 11 ◽

Author(s):

Yuman Cao ◽

Jinlong Liu ◽

Yuanying Li ◽

Jing Zhang ◽

Shuxia Li ◽

...

Keyword(s):

Medicago Truncatula ◽

Vascular Tissue ◽

Phosphate Transporter ◽

Vascular Bundles ◽

Transporter Gene ◽

Cortical Cells ◽

Close Relationship ◽

Localization Analysis ◽

Global Agriculture ◽

Almost All

Phosphorus is one of the essential macronutrients required by plant growth and development, but phosphate resources are finite and diminishing rapidly because of the huge need in global agriculture. In this study, 11 genes were found in the Phosphate Transporter 1 (PHT1) family of Medicago truncatula. Seven genes of the PHT1 family were available by qRT-PCR. Most of them were expressed in roots, and almost all genes were induced by low-phosphate stress in the nodule. The expression of MtPT6 was relatively high in nodules and induced by low-phosphate stress. The fusion expression of MtPT6 promoter-GUS gene in M. truncatula suggested that the expression of MtPT6 was induced in roots and nodules by phosphate starvation. In roots, MtPT6 was mainly expressed in vascular tissue and tips, and it was also expressed in cortex under low-phosphate stress; in nodules, it was mainly expressed in vascular bundles, cortical cells, and fixation zone cells. MtPT6 had a close relationship with other PHT1 family members according to amino acid alignment and phylogenetic analysis. Subcellular localization analysis in tobacco revealed that MtPT6 protein was localized to the plasma membrane. The heterologous expression of MtPT6 in Arabidopsis knockout mutants of pht1.1 and pht1.4 made seedlings more susceptible to arsenate treatment, and the phosphate concentrations in pht1.1 were higher in high phosphate condition by expressing MtPT6. We conclude that MtPT6 is a typical phosphate transporter gene and can promote phosphate acquisition efficiency of plants.

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Fractionation of cell-wall preparations from grass leaves by centrifuging in non-aqueous density gradients

Biochemical Journal ◽

10.1042/bj1930765 ◽

1981 ◽

Vol 193 (3) ◽

pp. 765-771 ◽

Cited By ~ 2

Author(s):

A H Gordon ◽

J S Bacon

Keyword(s):

Cell Wall ◽

Density Gradient ◽

Cell Walls ◽

Vascular Tissue ◽

Italian Ryegrass ◽

Vascular Bundles ◽

Density Gradients ◽

Roll Mill ◽

Close Relationship ◽

Polysaccharide Composition

1. Dried preparations of cell walls from perennial-ryegrass (Lolium perenne) and Italian-ryegrass (L. multiflorum) leaves were suspended in mixtures of carbon tetrachloride with light-petroleum (b.p. 45–50 degrees C) or alcohols and layered on density gradients formed from the same solvents. 2. On centrifugation, the cell walls become distributed throughout a suitably chosen gradient. Fractions corresponding to various regions of the gradient were separated, examined under the microscope and analysed. 3. Cell-wall preparations made from leaf material ground in liquid N2, or in a triple roll mill, showed considerable heterogeneity in particle size, and their behaviour in the density gradient was variable, although there was a general indication that walls derived from vascular bundles were less dense than those from sclerenchyma. 4 Treatment in a vibratory ball mill decreased the size of the particles and produced a more uniform material, but made it impossible to distinguish the origins of the particles. This material behaved more reproducibly in the density gradient. 5. Some fractionations were also made by successive centrifugation in media of increasing relative density. 6. Analyses of the fractions obtained by each method indicated that the less dense had a greater proportion of xylose in the polysaccharide components, and higher contents of acetyl groups and lignin, confirming the close relationship between these components in plant cell walls. 7. The results show that there are differences in polysaccharide composition between the cell-wall types in the grass leaf, the vascular tissue being richer in hemicellulose relative to cellulose than the sclerenchyma.

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