Leaf demography and the plastochron index

Ford, Henry

doi:10.1111/j.1095-8312.1982.tb02027.x

Cited by 10 publications

(4 citation statements)

References 37 publications

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“…Phyllochrons are often expressed in units of thermal time such as growing degree days (GDD) per phyllochron. In this later context, the phyllochron is related to the broadly applied plastochron index (Ford, 1982).…”

Section: Quantifying Developmental Morphology Phyllochron Indexmentioning

confidence: 99%

Quantifying Developmental Morphology of Perennial Grasses

1995

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Section: Quantifying Developmental Morphology Phyllochron Indexmentioning

confidence: 99%

Quantifying Developmental Morphology of Perennial Grasses

1995

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“…The leaf's precise morphological age, measured by the leaf plastochron index (LPI), can be determined by subtracting the number of leaves from the PI. This LPI has become the standard measure in the study of the morphological and physiological development of whole plants or plant organs (Lamoreaux et al, 1978; Ford, 1982; Ceulemans et al, 1988; Shaik et al, 1989; Groot and Meicenheimer, 2000).…”

mentioning

confidence: 99%

A new method to measure leaf age: Leaf measuring‐interval index

Chen¹,

Chen²,

Chen³

2009

American J of Botany

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We propose a new method, the leaf measuring-interval index (LMI), to estimate leaf age in morphological and physiological studies of leaves. When the plastochron, the interval between the initiation of successive leaves, is constant, the well-known leaf plastochron index (LPI) provides a robust measure of leaf age. When the duration of the plastochron is not uniform, however, we show that the LPI can (in simulations) and does (with actual data) turn variation in duration of the plastochron into variance about the regression estimates of leaf growth curves. The method we present in this paper, the LMI, is plastochron independent. This new method is particularly suited, therefore, for studies of plants growing in natural environments rather than in controlled growth facilities where the assumptions of the LPI method can be met.

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“…We used a 'leaf plastochron index' system [49] to assure that stems were at the same developmental stage for any given test or manipulation. We defined 'the apex' as the tight cluster of leaves above the first internode that could be clearly identified with the unaided eye.…”

Section: Methodsmentioning

confidence: 99%

Auxin-Responsive DR5 Promoter Coupled with Transport Assays Suggest Separate but Linked Routes of Auxin Transport during Woody Stem Development in Populus

Spicer

Tisdale-Orr²,

Talavera

2013

PLoS ONE

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Polar auxin transport (PAT) is a major determinant of plant morphology and internal anatomy with important roles in vascular patterning, tropic growth responses, apical dominance and phyllotactic arrangement. Woody plants present a highly complex system of vascular development in which isolated bundles of xylem and phloem gradually unite to form concentric rings of conductive tissue. We generated several transgenic lines of hybrid poplar (Populus tremula x alba) with the auxin-responsive DR5 promoter driving GUS expression in order to visualize an auxin response during the establishment of secondary growth. Distinct GUS expression in the cambial zone and developing xylem-side derivatives supports the current view of this tissue as a major stream of basipetal PAT. However, we also found novel sites of GUS expression in the primary xylem parenchyma lining the outer perimeter of the pith. Strands of primary xylem parenchyma depart the stem as a leaf trace, and showed GUS expression as long as the leaves to which they were connected remained attached (i.e., until just prior to leaf abscission). Tissue composed of primary xylem parenchyma strands contained measurable levels of free indole-3-acetic acid (IAA) and showed basipetal transport of radiolabeled auxin (3H-IAA) that was both significantly faster than diffusion and highly sensitive to the PAT inhibitor NPA. Radiolabeled auxin was also able to move between the primary xylem parenchyma in the interior of the stem and the basipetal stream in the cambial zone, an exchange that was likely mediated by ray parenchyma cells. Our results suggest that (a) channeling of leaf-derived IAA first delineates isolated strands of pre-procambial tissue but then later shifts to include basipetal transport through the rapidly expanding xylem elements, and (b) the transition from primary to secondary vascular development is gradual, with an auxin response preceding the appearance of a unified and radially-organized vascular cambium.

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Leaf demography and the plastochron index

Cited by 10 publications

References 37 publications

Quantifying Developmental Morphology of Perennial Grasses

Quantifying Developmental Morphology of Perennial Grasses

A new method to measure leaf age: Leaf measuring‐interval index

Auxin-Responsive DR5 Promoter Coupled with Transport Assays Suggest Separate but Linked Routes of Auxin Transport during Woody Stem Development in Populus

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