Ontogeny of the Open Dichotomous Venation in the Pinna of the Fern Nephrolepis

Pray, Thomas R.

doi:10.2307/2439217

Cited by 16 publications

(16 citation statements)

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“…Vascular plant leaves use internal airspaces regulated by stomata for gas exchange (Raven 1996;Boyce 2008a). Second, evidence from both living plants and the venation patterns of fossil leaves indicates that the ancestral form of tissue production in the growing leaves of all vascular plants was limited to discrete marginal zones of growth (Pray 1960;Zurakowski and Gifford 1988;Boyce and Knoll 2002;Boyce 2007). Other aspects of leaf organography, such as the evolution of differentiated abaxial/adaxial domains (see section on 'Proximal mechanisms underlying leaf shape diversity' below) and determinate leaf growth appear to arise independently in seed plants and other lineages, however, several of these lineages have co-opted the same underlying genetic pathways to regulate these developmental processes (see section on 'Proximal mechanisms underlying leaf shape diversity', Bharathan et al 2002;Harrison et al 2005;Sanders et al 2007;Tomescu 2009;Boyce 2010).…”

Section: A Brief History Of the Angiosperm Leaf And Shape Diversity Tmentioning

confidence: 99%

The evolution and functional significance of leaf shape in the angiosperms

Nicotra

Leigh

Boyce

et al. 2011

Functional Plant Biol.

442

396

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Abstract. Angiosperm leaves manifest a remarkable diversity of shapes that range from developmental sequences within a shoot and within crown response to microenvironment to variation among species within and between communities and among orders or families. It is generally assumed that because photosynthetic leaves are critical to plant growth and survival, variation in their shape reflects natural selection operating on function. Several non-mutually exclusive theories have been proposed to explain leaf shape diversity. These include: thermoregulation of leaves especially in arid and hot environments, hydraulic constraints, patterns of leaf expansion in deciduous species, biomechanical constraints, adaptations to avoid herbivory, adaptations to optimise light interception and even that leaf shape variation is a response to selection on flower form. However, the relative importance, or likelihood, of each of these factors is unclear. Here we review the evolutionary context of leaf shape diversification, discuss the proximal mechanisms that generate the diversity in extant systems, and consider the evidence for each the above hypotheses in the context of the functional significance of leaf shape. The synthesis of these broad ranging areas helps to identify points of conceptual convergence for ongoing discussion and integrated directions for future research.

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Section: A Brief History Of the Angiosperm Leaf And Shape Diversity Tmentioning

confidence: 99%

The evolution and functional significance of leaf shape in the angiosperms

Nicotra

Leigh

Boyce

et al. 2011

Functional Plant Biol.

442

396

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“…For 30 years, debates ensued about the existence, number and role of apical initial(s), and about the role of zonation within the apex (for a review, see White and Turner, 1995). The current consensus is that fern shoots, fronds and pinnae develop from one or two apical initials, with the actual number varying between species (Bierhorst, 1977;Hill, 2001;Pray, 1960). This consensus is derived from the examination of cleared shoot apices, histological sections and sequential surface imprints.…”

Section: Introductionmentioning

confidence: 99%

Sector analysis and predictive modelling reveal iterative shoot-like development in fern fronds

2011

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SUMMARYPlants colonized the terrestrial environment over 450 million years ago. Since then, shoot architecture has evolved in response to changing environmental conditions. Our current understanding of the innovations that altered shoot morphology is underpinned by developmental studies in a number of plant groups. However, the least is known about mechanisms that operate in ferns -a key group for understanding the evolution of plant development. Using a novel combination of sector analysis, conditional probability modelling methods and histology, we show that shoots, fronds ('leaves') and pinnae ('leaflets') of the fern Nephrolepis exaltata all develop from single apical initial cells. Shoot initials cleave on three faces to produce a pool of cells from which individual frond apical initials are sequentially specified. Frond initials then cleave in two planes to produce a series of lateral merophyte initials that each contributes a unit of three pinnae to half of the mediolateral frond axis. Notably, this iterative pattern in both shoots and fronds is similar to the developmental process that operates in shoots of other plant groups. Pinnae initials first cleave in two planes to generate lateral marginal initials. The apical and marginal initials then divide in three planes to coordinately generate the determinate pinna. These findings impact both on our understanding of fundamental plant developmental processes and on our perspective of how shoot systems evolved.

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“…Most ontogenic studies of ferns have focused on sporophytes, in which the frond development and cytohistochemical and cytohistology composition of shoot apex dominate (WARDLAW 1947(WARDLAW , 1948(WARDLAW , 1956CROTTY 1955;PRAY 1960;SAHA 1963;VON GUTTENBERG 1966;WHITE 1970WHITE , 1971MCALPIN & WHITE 1974;STEVEN-SON 1976a, b, 1978HAGEMANN 1984; ZURA- KOWSKI & GIFFORD 1988;IMAICHI & KATO 1992;HILL 2001). Vascular differentiation has received less attention.…”

Section: Introductionmentioning

confidence: 99%

“…(WARDLAW 1947), Tectaria CAV. (WHITE 1970) and Nephrolepis SCHOTT (PRAY 1960). BIERHORST (1977) studied frond development in more than 50 species of leptosporangiate ferns, and in all cases, the frond arises from an initial apical meristem cell.…”

Section: Introductionmentioning

confidence: 99%

Ontogeny of Ctenitis melanosticta (Kunze) Copel. and Diplazium expansumWilld. (Dryopteridaceae) fronds with emphasis on the circumendodermal sheath

2009

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Ontogeny of Ctenitis melanosticta (KUNZE) COPEL. and Diplazium expansum WILLD. (Dryopteridaceae) fronds with emphasis on the circumendodermal sheath With 7 Figures and 2 Tables SummaryThe ontogeny of Ctenitis melanosticta (KUNZE) COPEL. and Diplazium expansum WILLD. fronds was studied with the main goals to determine if continuous and discontinuous sheaths (bands in tranverse section) have the same origin in parenchyma cells. Frond ontogeny was followed from the crozier (fiddlehead) to the mature frond. Differentiation of the sheath begins during the crozier stage a few centimeters from the base of the stipe. As seen in transverse section, band differentiation occurs in the innermost parenchyma cells of the ground tissue, which surrounds the vascular strands of each vascular bundle of a multiple leaf trace. Based on its position and origin, it is named circumendodermal band (sheath in three dimensions) and the discontinuous form is designated "perforated sheath". The circumendodermal band and the endodermis arise from parenchyma cells. Both the continuous circumendodermal band in C. melanosticta and the discontinuous circumendodermal band in D. expansum differentiate from ground parenchyma cells surrounding each vascular bundle. In the lamina of C. melanosticta, the circumendodermal band differentiates when frond is fertile and in the lamina of D. expansum, it never differentiates. The circumendodermal band traits are not related to plant size, but to number of vascular strands.

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Ontogeny of the Open Dichotomous Venation in the Pinna of the Fern Nephrolepis

Cited by 16 publications

References 0 publications

The evolution and functional significance of leaf shape in the angiosperms

The evolution and functional significance of leaf shape in the angiosperms

Sector analysis and predictive modelling reveal iterative shoot-like development in fern fronds

Ontogeny of Ctenitis melanosticta (Kunze) Copel. and Diplazium expansumWilld. (Dryopteridaceae) fronds with emphasis on the circumendodermal sheath

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