Foliar Venation of Angiosperms. Ii. Histogenesis of the Venation of Liriodendron

Pray, Thomas R.

doi:10.1002/j.1537-2197.1955.tb11089.x

Cited by 46 publications

(21 citation statements)

References 9 publications

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“…The lower (more mature) cupule displays greater acropetal differentiation of the vascular strand than that observed in the more apical (less mature) cupule. It appears that the vascular strand in U. resinosa developed acropetally in the cupule, a condition that is known during leaf development in a number of modern seed plants (e.g., Pray, 1955;De Sloover, 1958;Postek and Tucker, 1982).…”

Section: Correlation Of Anatomy With Morphology-interpretationmentioning

confidence: 98%

Anatomy of Umkomasia (Corystospermales) from the Triassic of Antarctica

Klavins

Taylor

2002

American J of Botany

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The permineralized, corystosperm, cupulate, ovule-bearing organ Umkomasia resinosa is described from the early Middle Triassic of Antarctica. This is the first description of anatomically preserved Umkomasia, which consists of a determinate cupulate branch with helically arranged, recurved, pedicellate megasporophylls, each of which bears one or two abaxially attached unitegmic ovules. Cupules are ovoid, bilobed with elongate ventral and dorsal openings or unlobed with a single ventral opening, and have a two-zoned parenchymatous cortex and abundant secretory cavities. Ovules are small, orthotropous, and possess a thin integument that contains numerous secretory cavities. The ovules are broadly attached at the base, with a bifid integumentary apex that extends past the cupule lobes. The cupulate branch displays stem-like anatomy, producing paired traces into each cupule stalk. These structurally preserved ovulate organs can be related to other corystosperm organs from Antarctica, particularly the pollen-organ Pteruchus fremouwensis. Both anatomical and morphological features support interpretation of corystosperm reproductive structures as branching systems rather than as compound sporophylls. As a result of an increased understanding of the organization of Umkomasia, it appears doubtful that any direct relationship exists between the corystosperm and angiosperm lineages.

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Section: Correlation Of Anatomy With Morphology-interpretationmentioning

confidence: 98%

Anatomy of Umkomasia (Corystospermales) from the Triassic of Antarctica

Klavins

Taylor

2002

American J of Botany

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“…However, few branched structures have historically captured more widespread attention than the vein networks of plant leaves. From a developmental standpoint, such attention seems justified as files of vein precursor cells are selected from within a population of seemingly identical cells [1], [2]. Furthermore, in most species the product of this patterning process is both reproducible and variable: reproducible as vein networks supply all areas of the leaf; variable as the exact sites of vein formation are unpredictable [3].…”

Section: Introductionmentioning

confidence: 99%

Patterning of Leaf Vein Networks by Convergent Auxin Transport Pathways

2013

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The formation of leaf vein patterns has fascinated biologists for centuries. Transport of the plant signal auxin has long been implicated in vein patterning, but molecular details have remained unclear. Varied evidence suggests a central role for the plasma-membrane (PM)-localized PIN-FORMED1 (PIN1) intercellular auxin transporter of Arabidopsis thaliana in auxin-transport-dependent vein patterning. However, in contrast to the severe vein-pattern defects induced by auxin transport inhibitors, pin1 mutant leaves have only mild vein-pattern defects. These defects have been interpreted as evidence of redundancy between PIN1 and the other four PM-localized PIN proteins in vein patterning, redundancy that underlies many developmental processes. By contrast, we show here that vein patterning in the Arabidopsis leaf is controlled by two distinct and convergent auxin-transport pathways: intercellular auxin transport mediated by PM-localized PIN1 and intracellular auxin transport mediated by the evolutionarily older, endoplasmic-reticulum-localized PIN6, PIN8, and PIN5. PIN6 and PIN8 are expressed, as PIN1 and PIN5, at sites of vein formation. pin6 synthetically enhances pin1 vein-pattern defects, and pin8 quantitatively enhances pin1pin6 vein-pattern defects. Function of PIN6 is necessary, redundantly with that of PIN8, and sufficient to control auxin response levels, PIN1 expression, and vein network formation; and the vein pattern defects induced by ectopic PIN6 expression are mimicked by ectopic PIN8 expression. Finally, vein patterning functions of PIN6 and PIN8 are antagonized by PIN5 function. Our data define a new level of control of vein patterning, one with repercussions on other patterning processes in the plant, and suggest a mechanism to select cell files specialized for vascular function that predates evolution of PM-localized PIN proteins.

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“…The replicas were used to determine the size, number, and distribution of stomata. (Avery, 1933;Pray, 1955;Esau, 1965;Lersten, 1965;Olson, Tibbitts, and Struckmeyer, 1969). Lamina organization in cottonwood resembles that of many other dicotyledons and is blocked out comparatively early.…”

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confidence: 95%