Photosynthesis in Relation to Leaf Characteristics of Cotton from Controlled and Field Environments

Patterson, David T.; Bunce, James A.; Alberte, Randall S.; Volkenburgh, Elizabeth Van

doi:10.1104/pp.59.3.384

Cited by 75 publications

(43 citation statements)

References 19 publications

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“…Oscillations in the amount of Chl could explain the rhythm in photosynthetic rate at saturating light intensities (1,28). However, when Euglena is grown in constant dim light no obvious rhythm in Chl content (total mg Chl/cell) could be detected (data not shown).…”

Section: Pm) Photosynthesis Rhythm In Euglenamentioning

confidence: 96%

Regulation of the Photosynthesis Rhythm in Euglena gracilis

Lonergan¹,

Sargent²

1979

Plant Physiol.

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Rhythmic changes in the light reactions of Euglena gracilis have been found which help to explain the basic reactions effected in the circadian rhythm of 02 evolution. Diurnal changes in the slope of light intensity plots indicated that the maximal rate of photosynthesis changed throughout the circadian cycle. No evidence was obtained consistent with the premise that changes in chlorophyl content, as measured by total chlorophyl or chlorophyUl a/b ratio, or photosynthetic unit size are responsible for this rhythm.The rate of light-induced electron flow through the entire electron chain (H20 to methyl viologen) was rhythmic both in whole cells and in isolated chloroplasts, and the highest rate of electron flow coincided with the highest rate of 02 evolution. The individual activities of photosystem I (reduced form 2,6-dichlorophenol-indophenol to methyl viologen) and photosystem II (H20 to 2,6"dichlorophenol-indophenol) did not, however, change significantly with time of day, suggesting that the coordination of the two photosystems may be the site of circadian control. Evidence consistent with this concept was obtained from studies of low temperature emission from systems I and II folowing preillumination with system I or II light.A circadian rhythm of photosynthetic 02 evolution has been observed in several eukaryotic organisms (16) including Euglena (22). The mechanisms responsible for this rhythm have been investigated but never fully elucidated. Steady-state 02 evolution in whole cells is a function of both the light reactions and the enzyme activities of the Calvin cycle. The photosynthetic rhythm, however, does not seem attributable to rhythmic changes in the activity of any Calvin cycle enzyme (8, 15,22). Therefore, the light reactions would appear to be the most probable oscillator-controlled part of photosynthesis.Many

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Section: Pm) Photosynthesis Rhythm In Euglenamentioning

confidence: 96%

Regulation of the Photosynthesis Rhythm in Euglena gracilis

Lonergan¹,

Sargent²

1979

Plant Physiol.

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“…These increases in the amount of photosynthetic tissue included increases in mesophyll thickness (or volume/unit area), Chl content/unit area, PSU density/unit area, and specific leaf weight. Other workers have also shown that quantitative changes in the photosynthetic apparatus are important in accounting for photosynthetic adaptability to irradiance (7,13,14,16,17).…”

Section: Discussionmentioning

confidence: 99%

“…Stomatal and boundary layer resistances were subtracted from the total resistance to yield residual or mesophyll resistance. This calculation of mesophyll resistance includes differences in carboxylase activity as well as all other nonboundary layer and nonstomatal effects (16).…”

Section: Methodsmentioning

confidence: 99%

“…Measurement of CO2 Exchange. The rates of CO2 uptake of single leaves of cotton and velvetleaf were determined at ambient C02 and 02 concentrations with an IR gas analyzer and pincer cuvette described previously (16). Photosynthetic rates were determined in air containing 21% 02 at 30 C at six irradiances ranging from 90 to 2,000 ,uE m-2sec' PAR, provided by a 300-w incandescent lamp with a water filter.…”

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confidence: 99%

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Effects of Irradiance during Growth on Adaptive Photosynthetic Characteristics of Velvetleaf and Cotton

Patterson

Duke²,

Hoagland³

1978

Plant Physiol.

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We grew velvetleaf (Abutilon theophrasd Medic.) and cotton (Gossypium hirsutm L. var. Stoneville 213) at three irradiances and determined the photosynthetic responses of single leaves to a range of six irradiances from 90 to 2000 peinsteins m-2sec-'. In air containing 21% 02, velvetleaf and cotton grown at 750 peinsteins m-2sec-I had maximm photosynthetic rates of 18.4 and 21.9 mg of CO2 dm-2hr-', respectively. Maximum rates for leaves grown at 320 and 90 peinsteins m-2sec' were 15.3 and 10.3 mg of C02 dm-2hr-' in velvetleaf and 12 and 6.7 mg of CO2 dm-2hr-' in cotton, respetively. In 1 O2, maximum photosynthetic rates were 1.5 to 2.3 times the rates in air conting 21%°2, and plants grown at medium and high irradiance dW not differ in rate. In both species, stomatal conductance was not signflcantly affected by growth irradiance. The differences in maximum photosynthetic rates were associated with diferences in mesophyl con- Velvetleaf is a malvaceous annual weed of increasing importance to cotton growers (6). Chandler (6) reported cotton yield reductions of over 90%o with full season competition from dense infestations of velvetleaf. Both Chandler (6) and Bjorkman (4) have shown the need for comparative physiological studies to help explain competitive and environmental responses ofclosely related plants. Comparisons of such closely related weed and crop plants as velvetleaf and cotton should lead to a better understanding of weed-crop interactions.As part of a series of investigations of the comparative ecophysiology of weeds and crop plants, we studied the effects of irradiance during growth on the photosynthetic characteristics of velvetleaf and cotton. We determined the degree of adaptability of the photosynthetic apparatus to irradiance and the changes in some leaf characteristics which help to account for the adaptability. We also studied the effects of irradiance on certain growth parameters determined from mathematical growth analysis and related the differences in the growth parameters to differences in photosynthetic characteristics. were grown in a 1:1 (v/v) mixture of Bosket2 sandy loam and sand in a controlled environment chamber at a 31/25 C day/night temperature, 80%o relative humidity, and a 15-hr photoperiod. Light was supplied by a mixture of fluorescent and incandescent lamps. The temperature regime was chosen according to the method of Went (20) to represent average July day/night temperatures for Stoneville, Mississippi. The plants were grown in 15-cm pots and watered daily to field capacity with Hoagland solution. Screening in the chamber provided three irradiance levels during growth: 90, 320, and 750 ,tE m-2sec-1 PAR,3 400 to 700 nm. MATERIALSMeasurement of CO2 Exchange. The rates of CO2 uptake of single leaves of cotton and velvetleaf were determined at ambient C02 and 02 concentrations with an IR gas analyzer and pincer cuvette described previously (16). Photosynthetic rates were determined in air containing 21% 02 at 30 C at six irradiances ranging from 90 to 2,000 ,uE m-2sec' ...

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“…CO2 concentration was 350 or 1000 Ml L-' CO2. Plant density was 97 m 2 before transplanting (15 d Thirty five, 42, and 58 d after seeding gas exchange was measured using a small, hand-held cuvette enclosing both upper and lower leaf surfaces Patterson et al [21 ] for cuvette description) and a Beckman 865 IR gas analyzer. All measurements were made inside the growth chambers, selecting the uppermost fully expanded leaf on each of eight plants.…”

Section: Methodsmentioning

confidence: 99%