The Association of Druse Crystals With the Developing Stomium of Capsicum Annuum (Solanaceae) Anthers

Horner, Harry T.; Wagner, Bruce L.

doi:10.1002/j.1537-2197.1980.tb07767.x

Cited by 66 publications

(15 citation statements)

References 24 publications

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“…Macromolecular structures such as intravacuolar matrices (e.g., crystal chambers) have been suggested to play an important role in determining a crystal's morphology (Arnott and Pautard 1970;Horner and Wagner 1980;Webb and Arnott 1983;Barnabas and Arnott 1990;Webb et al 1995). Crystal chambers appear to form a lipid and polysaccharide partition, separating the vacuolar compartment from the space in which the crystal develops.…”

Section: Discussionmentioning

confidence: 98%

“…Crystal chambers appear to form a lipid and polysaccharide partition, separating the vacuolar compartment from the space in which the crystal develops. The shape of the crystal can often be predicted before it actually forms based on the shape of these membrane chambers (Arnott and Pautard 1970;Horner and Wagner 1980;Webb and Arnott 1983;Barnabas and Arnott 1990). In addition, Kausch and Horner (1984) have shown, using Yucca root, that lamellated sheaths can be seen surrounding the raphide crystals.…”

Section: Discussionmentioning

confidence: 99%

“…It has been hypothesized that a number of factors play a role in defining crystal shape and size. These factors include macromolecules such as proteins, polysaccharides, and lipids, as well as macromolecular structures such as crystal chambers and cell walls (Horner and Wagner 1980;Arnott and Webb 1983;Webb 1999).…”

Section: Introductionmentioning

confidence: 99%

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Calcium oxalate crystal morphology mutants from Medicago truncatula

McConn

Nakata

2002

Planta

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Plants accumulate crystals of calcium oxalate in a variety of shapes and sizes. The mechanism(s) through which a plant defines the morphology of its crystals remains unknown. To gain insight into the mechanisms regulating crystal shapes, we conducted a mutant screen to identify the genetic determinants. This is the first reported mutant screen dedicated to the identification of crystal morphology mutants. A single leaf was harvested from individual Medicago truncatula L. plants that had been chemically mutagenized. Each leaf was visually inspected, using crossed-polarized light microscopy, for alterations in crystal shape and size. Seven different crystal morphology defective ( cmd) mutants were identified. Six cmd mutants were recessive and one dominant. Genetic analysis of the six recessive mutants suggested that each mutant was affected at a different locus. Each cmd mutant represents a new locus different than any previously identified. The plant phenotype of the cmd mutants appeared similar to that of the wild type in overall growth and development. This observation, coupled with the finding that several of the mutants had drastically altered the amount of calcium they partition into the oxalate crystal, questions current hypotheses regarding crystal function. Comparisons between the mutant crystals and those present in other legumes indicated the likelihood that simple point mutations contributed to the evolution of the variations in prismatic crystal shapes commonly observed in these plants today. The availability of cmd mutants provides the opportunity to investigate aspects of crystal shape and size that have been recalcitrant to previous approaches.

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Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

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Calcium oxalate crystal morphology mutants from Medicago truncatula

McConn

Nakata

2002

Planta

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“…4; 6F). In addition, calcium oxalate druse crystals (Horner and Wagner 1980;D'Arcy et al 1996) were present within the large vacuoles of the stage +2 circular cell cluster and were visualized as ''white-star'' shapes in TEM micrographs (Figs. 4; 6F).…”

Section: The Circular Cell Cluster Is Derived From Cells Of the Primomentioning

confidence: 99%

Differentiation and degeneration of cells that play a major role in tobacco anther dehiscence

Sanders

Bui

et al. 2004

Sex Plant Reprod

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Dehiscence is the terminal step in anther development that releases pollen grains from the wall of each theca at a specific site between the two locules. In tobacco, two groups of cells-the circular cell cluster and the stomium-are required for anther dehiscence and define the position at which pollen is released. The processes responsible for the differentiation of the circular cell cluster and the stomium from cells in specific anther regions are unknown. Nor is it understood what initiates the programmed degeneration of these cell types that ultimately is responsible for pollen release from the anther. We characterized stomium and circular cell cluster differentiation and degeneration using both light and transmission electron microscopy throughout anther development, from the emergence of stamen primordia to anther dehiscence at flower opening. We observed that histological changes within primordium L1 and L2 cells destined to become the stomium and circular cell cluster occur at the same time after the differentiation of surrounding locule regions. Sub-epidermal cells that differentiate into the circular cell cluster divide, enlarge, and generate vacuoles with calcium oxalate crystals prior to any detectable changes in prestomium epidermal cells. Differentiation and division of cells that generate the stomium occur after cell degeneration initiates in the circular cell cluster. Prior to dehiscence, the stomium consists of a small set of cytoplasmically dense cells that are easily distinguished from their larger, highly vacuolate epidermal neighbors. Plasmodesmata connections within and between cells of the stomium and circular cell cluster were observed at different developmental stages, suggesting that these cells communicate with each other. Circular cell cluster and stomium cell death is programmed developmentally and occurs at different times. Degeneration of the circular cell cluster occurs first, contributes to the formation of a bilocular anther, and generates the site of anther wall breakage. The stomium cell death process is complete at flower opening and provides an opening for pollen release from each theca. We used laser capture microdissection and real-time quantitative reverse-transcription polymerase chain reactions to demonstrate that stomium cells can be isolated from developing anthers and studied for the presence of specific mRNAs. Our data suggest that a cascade of unique gene expression events throughout anther development is required for the dehiscence program, and that the differentiation of the stomium and circular cell cluster in the interlocular region of the anther probably involves cell signaling processes.

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“…8), has been reported in the anther septum of Lycopersicum esculentum and Capsicum annuum (Solanaceae) (Bonner and Dickinson, 1989;Horner and Wagner, 1980), and it is postulated that they play a role in the weakening and eventual enzymic dissolution of the septa. In Parietaria, these druse-containing cells in the filament may have a similar role in weakening the filament for straightening and dispersal.…”

Section: Article In Pressmentioning

confidence: 95%