Studies on the Expansion of the Leaf Surface: III. THE INFLUENCE OF RADIATION ON CELL DIVISION AND LEAF EXPANSION

Milthorpe, F. L.; Newton, P.

doi:10.1093/jxb/14.3.483

Cited by 94 publications

(52 citation statements)

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“…As development continues, division persists but cell expansion becomes an important component of leaf growth. When the leaf approaches maturity, growth continues despite cessation of division (7,10,15). If a similar developmental plan exists in field pennycress, then the loss of sensitivity to GA3 observed in older leaves (Fig.…”

Section: Methodsmentioning

confidence: 94%

Gibberellins and Light Regulated Petiole Growth in Thlaspi arvense L

Metzger¹

1988

Plant Physiol.

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Petiole growth in Thlaspi arvense L. was stimulated when a basic 8 hour photoperiod (4.20 milliwatts per square centimeter) was extended with low intensity light (0.16 milliwatt per square centimeter) from incandescent lamps. The day length extension was effective only when the light contained high proportions of far red light. Exogenous gibberellin A3 (GA3) could partially substitute for the promotive effect of the extended photoperiod. Moreover, the GA biosynthesis inhibitor 2-chlorocholine chloride inhibited the increase in petiole growth induced by the extended photoperiod. However, evidence was obtained indicating that gibberellins do not mediate the effect of the extended photoperiod. First, petiole growth was greater in plants receiving both exogenous GA3 and a day length extension than the sum of the effects of the two treatments alone. Second, petioles were sensitive to exogenous GA3 only during the early stages of leaf development, whereas mature (but not senescent) leaves continued to respond to an extension of the photoperiod. Third, the cellular basis for growth induced by extending the photoperiod was different from that observed with GA3. It was concluded that light and gibberellins are both important in the overall regulation of petiole growth, but act through independent mechanisms.Field pennycress (Thlaspi arvense L.) is a winter annual weed that has a cold requirement for stem elongation and flowering. Work in this laboratory has been focused on the role of GAs' in the environmental control of stem elongation in this species (8,9). During the course of these studies we observed that photoperiod exerts a strong influence on leaf growth, particularly petiole length. Petioles from plants that had been transferred to LD were longer than from plants maintained under SD. Furthermore, application of GA3 to plants in SD caused petioles to elongate, thereby mimicking the effect of LD. These observations suggest that GAs may mediate the observed LD-induced increase in petiole growth. Indeed, evidence for a role of GAs in this phenomenon in spinach has been published (21). Thus, in the present paper we report the results of experiments with two objectives in mind: first, to characterize more completely the role of light in the regulation of petiole growth in field pennycress; and second, to test the hypothesis that GAs mediate LD-induced petiole growth. pots filled with vermiculite. The pots were continuously subirrigated with one-quarter strength Hoagland solution (1). The plants were grown under SD conditions at 21°C until they were ready for use, approximately 6 weeks after germination. MATERIALS AND METHODSLight Treatments. SD treatments consisted of 8 h of light from fluorescent and incandescent lamps (4.20 mW cm-2) followed by 16 h of darkness. LD treatments were composed of the same basic 8 h photoperiod as SD followed by 16 h of low intensity illumination from incandescent lamps (0.16 mW cm-2).The spectral dependency of the LD response was investigated by subjecting plants to 16 h of low ...

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Section: Methodsmentioning

confidence: 94%

Gibberellins and Light Regulated Petiole Growth in Thlaspi arvense L

Metzger¹

1988

Plant Physiol.

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“…Besides water availability, nitrogen supply, radiation and temperature are environmental factors that are known to influence leaf expansion (Milthorpe and Newton 1963;Radin and Boyer 1982;Tardieu and others 1999;Harrington and others 2001). The radiation regime during leaf flushing is crucial for developing the sun leaf/shade leaf dichotomy within the crown (Kim and others 2005).…”

Section: Environmental Controls Of Forest Leaf Areamentioning

confidence: 99%

Leaf Size and Leaf Area Index in Fagus sylvatica Forests: Competing Effects of Precipitation, Temperature, and Nitrogen Availability

2008

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Plants across diverse biomes tend to produce smaller leaves and a reduced total leaf area when exposed to drought. For mature trees of a single species, however, the leaf area-water supply relationship is not well understood. We tested the paradigm of leaf area reduction upon drought by a transect study with 14 mature Fagus sylvatica forests along a steep precipitation gradient (970-520 mm y )1 ) by applying two independent methods of leaf size determination. Contrary to expectation, average leaf size in dry stands (520-550 mm y )1 ) was about 40% larger and SLA was higher than in moist stands (910-970 mm y )1 ). As a result of increased leaf sizes, leaf area index significantly increased from the high-to the low-precipitation stands. Multiple regression analyses suggested that average leaf size was primarily controlled by temperature, whereas the influence of soil moisture and soil C/N ratio was low. Summer rainfall of the preceding year was the most significant predictor of total leaf number. We assume that leaf expansion of beech was independent of water supply, because it takes place in May with ample soil water reserves along the entire transect. In contrast, bud formation, which determines total leaf number, occurs in mid-summer, when droughts are severest. We conclude that leaf expansion and stand leaf area of beech along this precipitation gradient are not a simple function of water availability, but are controlled by several abiotic factors including spring temperature and possibly also nitrogen supply, which both tend to increase toward drier sites, thus overlaying any negative effect of water shortage on leaf development.

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“…However its effect on leaf expansion is controversial. Increasing PPFD can affect final leaf area either positively (Milthorpe & Newton 1963; Hussey fore difficult to compare expansion rates of plants of two treatments which may be at slightly different stages of development at a given time. We have recently proposed a framework of analysis of sunflower leaf development which makes comparisons easier (Granier & Tardieu 1998b).…”

Section: Introductionmentioning

confidence: 99%

Leaf expansion and cell division are affected by reducing absorbed light before but not after the decline in cell division rate in the sunflower leaf

Granier

Tardieu

1999

Plant Cell & Environment

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The effect of absorbed photosynthetic photon flux density (PPFD) on leaf expansion is a key issue for analysing the phenotypic variability between plants and for modelling feedback loops. Expansion and epidermal cell division in leaf 8 of sunflower were analysed in a series of five experiments where absorbed photosynthetic photon flux density (PPFD) was reduced either by shading or by covering part of the leaf area. These treatments were imposed at different times during leaf development. Expansion and cell division were affected by a reduction in absorbed PPFD only in the first part of leaf development, while the leaf area was less than 2% of its final value and while absolute expansion rate was slow. In contrast, it was not affected if imposed later when the leaf was visible and absolute expansion rate was at maximum. A reduction in absorbed PPFD caused the same reduction in expansion and in cell division whether it was due to a reduction in incident PPFD or to a reduction in photosynthetic leaf area, suggesting that carbon metabolism was involved. Relative expansion rate recovered to control levels when relative division rate began to decline, in all experiments and in all zones of a leaf. This was probably linked to the source-sink transition, after which the leaf had such a high priority in carbon allocation that it was largely insensitive to changes in absorbed PPFD. The final leaf area was therefore closely related to the cumulated PPFD absorbed by the plant from leaf initiation to the end of exponential cell division.

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Studies on the Expansion of the Leaf Surface: III. THE INFLUENCE OF RADIATION ON CELL DIVISION AND LEAF EXPANSION

Cited by 94 publications

References 0 publications

Gibberellins and Light Regulated Petiole Growth in Thlaspi arvense L

Gibberellins and Light Regulated Petiole Growth in Thlaspi arvense L

Leaf Size and Leaf Area Index in Fagus sylvatica Forests: Competing Effects of Precipitation, Temperature, and Nitrogen Availability

Leaf expansion and cell division are affected by reducing absorbed light before but not after the decline in cell division rate in the sunflower leaf

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