Integrated responses of rosette organogenesis, morphogenesis and architecture to reduced incident light in Arabidopsis thaliana results in higher efficiency of light interception

2005 ◽  
Vol 32 (12) ◽  
pp. 1123 ◽  
Author(s):  
Karine Chenu ◽  
Nicolas Franck ◽  
Jean Dauzat ◽  
Jean-François Barczi ◽  
Hervé Rey ◽  
...  

Plants have a high phenotypic plasticity in response to light. We investigated changes in plant architecture in response to decreased incident light levels in Arabidopsis thaliana (L.) Heynh, focusing on organogenesis and morphogenesis, and on consequences for the efficiency of light interception of the rosette. A. thaliana ecotype Columbia plants were grown under various levels of incident photosynthetically active radiation (PAR), with blue light (BL) intensity proportional to incident PAR intensity and with a high and stable red to far-red light ratio. We estimated the PAR absorbed by the plant, using data from precise characterisation of the light environment and 3-dimensional simulations of virtual plants generated with AMAPsim software. Decreases in incident PAR modified rosette architecture; leaf area decreased, leaf blades tended to be more circular and petioles were longer and thinner. However, the efficiency of light interception by the rosette was slightly higher in plants subjected to lower PAR intensities, despite the reduction in leaf area. Decreased incident PAR delayed leaf initiation and slowed down relative leaf expansion rate, but increased the duration of leaf expansion. The leaf initiation rate and the relative expansion rate during the first third of leaf development were related to the amount of PAR absorbed. The duration of leaf expansion was related to PAR intensity. The relationships identified could be used to analyse the phenotypic plasticity of various genotypes of Arabidopsis. Overall, decreases in incident PAR result in an increase in the efficiency of light interception.

1994 ◽  
Vol 74 (1) ◽  
pp. 31-36 ◽  
Author(s):  
D. W. Stewart ◽  
L. M. Dwyer

Date of appearance and expansion duration of leaves are critical parameters for calculating leaf area of a canopy, which is, in turn, an important component of growth. In this study, a three-line function and a logistic function were both fitted to normalized leaf area data of individual leaves from field-grown plants. Algorithms were developed relating leaf appearance time, expansion rate and expansion duration to growing degree days (GDD) from emergence. Leaf appearance time was a nonlinear function of leaf number. Both leaf expansion rate (RN) and leaf expansion duration (LN) were bell-shaped functions of leaf number (N) with RN skewed toward a lower value and LN skewed toward a higher value of N. These algorithms were used to develop a model of leaf area development detailed in a companion paper. Key words: Temperature, water stress, leaf area


1992 ◽  
Vol 72 (1) ◽  
pp. 117-126 ◽  
Author(s):  
M. J. Morrison ◽  
D. W. Stewart ◽  
P. B. E. McVetty

The vegetative development phase in summer rape (Brassica napus) is characterized by the appearance and expansion of leaves. The objectives of this research were to examine the maximum individual leaf area (LAmax), leaf expansion rate (LAX) and leaf area duration (LAD) of individual leaves as influenced by leaf position and ambient air temperature. Westar summer rape was grown from seed to maturity in controlled environment chambers set at temperatures ranging from 10 to 25 °C. Plants representing each stage of leaf development were selected at random from the population for leaf area determination. Logistic equations were used to relate the area of individual leaves to Growing Degree Days (GDD). Polynomial regression equations were used to fit curves describing the relationship between LAmax, LAX, LAD and leaf position or air temperature. As the air temperature increased the LAmax increased. LAX increased to a maximum which occurred when LAmax was at its maximum. There were no significant differences for LAX among air temperatures ranging from 13.5 to 22 °C. Mean LAX was 0.21 cm2 GDD−1. There were no significant differences in LAD due to leaf position or air temperature. Mean LAD was 140.1 GDD.Key words: Leaf area, leaf expansion rate, leaf area duration, Brassica napus


2021 ◽  
Vol 11 ◽  
Author(s):  
Wenqing Jin ◽  
Jorge Leigh Urbina ◽  
Ep Heuvelink ◽  
Leo F. M. Marcelis

The economic viability and energy use of vertical farms strongly depend on the efficiency of the use of light. Increasing far-red radiation (FR, 700–800 nm) relative to photosynthetically active radiation (PAR, 400–700 nm) may induce shade avoidance responses including stem elongation and leaf expansion, which would benefit light interception, and FR might even be photosynthetically active when used in combination with PAR. The aims of this study are to investigate the interaction between FR and planting density and to quantify the underlying components of the FR effects on growth. Lettuce (Lactuca sativa cv. Expertise RZ) was grown in a climate chamber under two FR treatments (0 or 52 μmol m–2 s–1) and three planting densities (23, 37, and 51 plants m–2). PAR of 89% red and 11% blue was kept at 218 μmol m–2 s–1. Adding FR increased plant dry weight after 4 weeks by 46–77% (largest effect at lowest planting density) and leaf area by 58–75% (largest effect at middle planting density). Radiation use efficiency (RUE: plant dry weight per unit of incident radiation, 400–800 nm) increased by 17–42% and incident light use efficiency (LUEinc: plant dry weight per unit of incident PAR, 400–700 nm) increased by 46–77% by adding FR; the largest FR effects were observed at the lowest planting density. Intercepted light use efficiency (LUEint: plant dry weight per unit of intercepted PAR) increased by adding FR (8–23%). Neither specific leaf area nor net leaf photosynthetic rate was influenced by FR. We conclude that supplemental FR increased plant biomass production mainly by faster leaf area expansion, which increased light interception. The effects of FR on plant dry weight are stronger at low than at high planting density. Additionally, an increased LUEint may contribute to the increased biomass production.


1956 ◽  
Vol 7 (5) ◽  
pp. 377 ◽  
Author(s):  
RW Brougham

A pasture association comprising short-rotation ryegrass, red clover, and white clover was subjected to three different intensities of defoliation by cutting down to 1, 3, and 5 in. At 4-day intervals over a period of 32 days, measurements were taken of herbage dry matter yield, the leaf area per unit area of ground, and the percentage of light penetrating to a level 1 in. above the ground surface. Where pasture was defoliated to 1 in., light interception was almost complete (95 per cent. or over) approximately 24 days after cutting, whereas pastures defoliated to 3 in. and 5 in. intercepted almost all the incident light 16 and 4 days after cutting respectively. At these stages of growth the leaf area was approximately 5 sq. ft per sq. ft of ground and the herbage yield approximately 1450 lb dry matter per acre, regardless of treatment. The rate of pasture growth increased until complete light interception was approached, and thereafter an almost constant maximum rate was sustained. Leaf efficiency (the rate of increase of herbage dry weight per unit area of leaf) was greatly influenced by intensity of defoliation. Efficiency was initially lower following severe defoliation than following less severe treatment. It increased rapidly to a maximum and thereafter declined gradually. Maximum efficiency in the 3 in. and 5 in. cutting treatments was attained when maximum growth rate was first reached. For pasture defoliated to 1 in., it reached a maximum level during the phase of accelerating growth.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 468b-468
Author(s):  
Stephen F. Klauer ◽  
J. Scott Cameron ◽  
Chuhe Chen

After promising results were obtained with an open-style split trellis (two top wires) in its initial year, two new trials were established in 1997 in northwest (Lynden) and southwest (Woodland) Washington. For the split trellis, actual yields were 33% (machine-picked 1/2 season) and 17% (hand-picked) greater, respectively, for the two locations compared to the conventional trellis (one top wire). In Woodland, canes from the split trellis had 33% more berries, 55% more laterals, 69% more leaves, and 25% greater leaf area compared with the conventional trellis. Greatest enhancement of these components was in the upper third of the canopy. Laterals were also shorter in this area of the split canopy, but there was no difference in average total length of lateral/cane between trellis types. Total dry weight/cane was 22% greater in the split trellis, but component partitioning/cane was consistent between the two systems with fruit + laterals (43%) having the greatest above-ground biomass, followed by the stem (30% to 33%) and the leaves (21% to 22%). Measurement of canopy width, circumference, and light interception showed that the split-trellis canopy filled in more quickly, and was larger from preanthesis through postharvest. Light interception near the top of the split canopy was 30% greater 1 month before harvest with 98% interception near the top and middle of that canopy. There was no difference between the trellis types in leaf CO2 assimilation, spectra, or fluorescence through the fruiting season, or in total nitrogen of postharvest primocane leaves.


Crop Science ◽  
1998 ◽  
Vol 38 (3) ◽  
pp. 827-834 ◽  
Author(s):  
I. C. Madakadze ◽  
B. E. Coulman ◽  
P. Peterson ◽  
K. A. Stewart ◽  
R. Samson ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 637
Author(s):  
Paul Kusuma ◽  
Boston Swan ◽  
Bruce Bugbee

The photon flux in the green wavelength region is relatively enriched in shade and the photon flux in the blue region is selectively filtered. In sole source lighting environments, increasing the fraction of blue typically decreases stem elongation and leaf expansion, and smaller leaves reduce photon capture and yield. Photons in the green region reverse these blue reductions through the photoreceptor cryptochrome in Arabidopsis thaliana, but studies in other species have not consistently shown the benefits of photons in the green region on leaf expansion and growth. Spectral effects can interact with total photon flux. Here, we report the effect of the fraction of photons in the blue (10 to 30%) and green (0 to 50%) regions at photosynthetic photon flux densities of 200 and 500 µmol m−2 s−1 in lettuce, cucumber and tomato. As expected, increasing the fraction of photons in the blue region consistently decreased leaf area and dry mass. By contrast, large changes in the fraction of photons in the green region had minimal effects on leaf area and dry mass in lettuce and cucumber. Photons in the green region were more potent at a lower fraction of photons in the blue region. Photons in the green region increased stem and petiole length in cucumber and tomato, which is a classic shade avoidance response. These results suggest that high-light crop species might respond to the fraction of photons in the green region with either shade tolerance (leaf expansion) or shade avoidance (stem elongation).


Sign in / Sign up

Export Citation Format

Share Document