A model for the role of surfactants in the assembly of exine sculpture

Hemsley, Alan R.; Griffiths, Peter C.; Mathias, Robert; Moore, Susannah

doi:10.1080/00173130303919

Cited by 8 publications

(10 citation statements)

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“…A more recent interpretation of the exine substructure is based on the properties of surfactant molecules dispersed in a liquid colloids. According to this model, amphiphobic molecules within the glycoclayx form micelles of various shapes, including spheroids, cylinders and bilayers (Hemsley et al, 2003;Gabarayeva & Hemsley, 2006;Hemsley & Gabarayeva, 2007). This concept extends an earlier model for the formation of TPL, in which the electron-lucent central layer was interpreted as the hydrophobic regions of long-chain fatty acids and the electron-dense layers as their hydrophilic ends in complex with phenolic compounds (Scott, 1994).…”

Section: Review 491supporting

confidence: 62%

Pollen wall development in flowering plants

et al. 2007

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Contents Summary 483 Introduction 483 Progress of research on pollen wall development 485 The developmental role of the special cell wall 487 Meiosis and the establishment of microspore symmetry 489 The origins of the exine during the tetrad stage 490 The free microspore stage to pollen maturation 495 Conclusions 495 Acknowledgements 496 References 496 Summary The outer pollen wall, or exine, is more structurally complex than any other plant cell wall, comprising several distinct layers, each with its own organizational pattern. Since elucidation of the basic events of pollen wall ontogeny using electron microscopy in the 1970s, knowledge of their developmental genetics has increased enormously. However, self‐assembly processes that are not under direct genetic control also play an important role in pollen wall patterning. This review integrates ultrastructural and developmental findings with recent models for self‐assembly in an attempt to understand the origins of the morphological complexity and diversity that underpin the science of palynology.

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Section: Review 491supporting

confidence: 62%

Pollen wall development in flowering plants

et al. 2007

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“…The process of these suberinsomes’ in vitro formation resembles that of cutinsome creation. It is also worth noting that self-assembly processes were also implicated in exine development in more than 30 plant species from a wide variety of taxa [ 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 ]. Moreover, GELP77 , a GDSL-type esterase/lipase gene that is mainly expressed in Arabidopsis microspores and tapetal cells [ 106 ] at early stages of flower development [ 107 ], has recently been shown to participate in pollen wall development and has been suggested to play a similar function in pollen to that of CUS1 in S. lycopersicum fruit cuticle [ 106 ].…”

Section: Discussionmentioning

confidence: 99%

The Role of Cutinsomes in Plant Cuticle Formation

Stępiński

Kwiatkowska

Wojtczak

et al. 2020

Cells

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The cuticle commonly appears as a continuous lipophilic layer located at the outer epidermal cell walls of land plants. Cutin and waxes are its main components. Two methods for cutin synthesis are considered in plants. One that is based on enzymatic biosynthesis, in which cutin synthase (CUS) is involved, is well-known and commonly accepted. The other assumes the participation of specific nanostructures, cutinsomes, which are formed in physicochemical self-assembly processes from cutin precursors without enzyme involvement. Cutinsomes are formed in ground cytoplasm or, in some species, in specific cytoplasmic domains, lipotubuloid metabolons (LMs), and are most probably translocated via microtubules toward the cuticle-covered cell wall. Cutinsomes may additionally serve as platforms transporting cuticular enzymes. Presumably, cutinsomes enrich the cuticle in branched and cross-linked esterified polyhydroxy fatty acid oligomers, while CUS1 can provide both linear chains and branching cutin oligomers. These two systems of cuticle formation seem to co-operate on the surface of aboveground organs, as well as in the embryo and seed coat epidermis. This review focuses on the role that cutinsomes play in cuticle biosynthesis in S. lycopersicum, O. umbellatum and A. thaliana, which have been studied so far; however, these nanoparticles may be commonly involved in this process in different plants.

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“…This idea was worked out in the field of sporoderm development (Gerasimova-Navashina 1973;van Uffelen 1991;Hemsley et al 1992;Collinson et al 1993;Gabarayeva 1993; and received some confirmation in modelling experiments (Hemsley et al 1996a(Hemsley et al , b, 1998(Hemsley et al , 2003Griffiths and Hemsley 2001;Moore et al 2009). Our recent hypothesis develops the self-assembling idea in that all the processes of exine development in the periplasmic space are based on unfolding the sequence of the micellar mesophase of surface-active substances (Gabarayeva and Hemsley 2006;Hemsley and Gabarayeva 2007).…”

Section: Introductionmentioning

confidence: 95%

I. Primexine development in Passiflora racemosa Brot.: overlooked aspects of development

2013

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Developmental stages during the tetrad period were examined in detail by transmission electron microscopy with an emphasis on substructure. Our purpose was to find out whether the sequence of sporoderm developmental events provides additional evidence for our recent hypothesis on the underlying cause of exine ontogeny as a sequence of self-assembling micellar mesophases initiated by genomically given physicochemical parameters. Osmiophilic globules encrusting the surface of postmeiotic microspores and tapetal cells are temporary prepattern units which come first. The second prepattern structures are highly ordered bundles of microfilaments and microtubules which determine the position of microspore surface invaginations and clusters of the glycocalyx inside them. The first glycocalyx units are microgranules which during the middle tetrad stage rearrange into radially oriented rodlike units. The latter form lens-like clusters of the glycocalyx-1, located inside the invaginations. These clusters predestine the position of the future luminae in the exine reticulum. The second glycocalyx layer is laid down as a continuous layer over the whole microspore surface and has similar substructure, that is radial rods. Glycocalyx-2 is a framework for procolumellae which appear at the late tetrad stage. Therefore, the sequence of substructural units in the primexine is: globules, microgranules, rod-like units, and layers of radially oriented rods tightly packed in the periplasmic space. This sequence corresponds to the first three mesophases of self-assembling micelles: spherical micelles, cylindrical micelles, and layers of hexagonally packed cylindrical micelles (middle mesophase). We observed the same sequence in other species during primexine development, and the findings of this study provide new evidence for our hypothesis.

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A model for the role of surfactants in the assembly of exine sculpture

Cited by 8 publications

References 0 publications

Pollen wall development in flowering plants

Pollen wall development in flowering plants

The Role of Cutinsomes in Plant Cuticle Formation

I. Primexine development in Passiflora racemosa Brot.: overlooked aspects of development

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