scholarly journals High Root-zone Temperatures Influence RuBisCO Activity and Pigment Accumulation in Leaves of `Rotundifolia' Holly

1992 ◽  
Vol 117 (1) ◽  
pp. 154-157 ◽  
Author(s):  
John M. Ruter ◽  
Dewayne L. Ingram
Keyword(s):  
Root Zone ◽  
Fresh Weight ◽  
Rubisco Activity ◽  
Bisphosphate Carboxylase ◽  
Root Zone Temperature ◽  
Root Zones ◽  
Protein Levels ◽  
Leaf Soluble Protein ◽  
Pigment Accumulation ◽  
Zone Temperature

Plants of `Rotundifolia' holly (Ilex crenata Thunb.) were grown for 3 weeks with root zones at 30,34,38, or 42C for 6 hours daily to evaluate the effects of supraoptimal root-zone temperatures on various photosynthetic processes. After 3 weeks, photosynthesis of plants grown with root zones at 38 or 42C was below that of plants grown at 30 or 34C. Chlorophyll and carotenoid levels decreased while leaf soluble protein levels increased as root-zone temperature increased. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) activity per unit protein and per unit chlorophyll responded quadratically, while RuBisCO activity per unit fresh weight increased linearly in response to increasing root-zone temperature. Results of this study suggest that `Rotundifolia' holly was capable of altering metabolism or redistributing available assimilates to maintain CO2 assimilation rates in response to increasing root-zone temperatures.

scholarly journals INFLUENCE OF SUPRAOPTIMAL ROOT-ZON E TEMPERATURES ON RUBISCO ACTIVITY, CHLOROPHYLL AND CAROTENOID LEVELS IN `ROTUNDIFOLIA' HOLLY

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 771C-771
Author(s):  
John M. Ruter ◽  
Dewayne L. Ingram
Keyword(s):  
Chlorophyll A ◽  
Soluble Protein ◽  
Root Zone ◽  
Nitrogen Nutrition ◽  
Photosynthetic Pigment ◽  
Total Chlorophyll ◽  
Rubisco Activity ◽  
Root Zone Temperature ◽  
Protein Levels ◽  
Zone Temperature

High root-zone temperatures have been shown to affect photosynthate partitioning, respiration, nitrogen nutrition and growth of `Rotundifolia' holly. The loss of chlorophyll and protein in shoots of other plants in response to high root-zone temperatures has been documented. Therefore, the objectives of this research were to look at the effects of supraoptimal root-zone temperatures on RUBISCO activity, leaf protein and photosynthetic pigment levels. Soluble protein levels in leaves increased linearly as root-zone temperature increased from 30 to 42 C. RUBISCO activity per unit protein and per unit chlorophyll responded quadratically to root-zone temperatures. Total chlorophyll, chlorophyll a & b, and carotenoid levels decreased linearly with increasing root-zone temperature. It is possible that `Rotundifolia' holly was capable of redistributing nitrogen to maintain RUBISCO activity for photosynthesis.

scholarly journals Plant Factories Are Heating Up: Hunting for the Best Combination of Light Intensity, Air Temperature and Root-Zone Temperature in Lettuce Production

2021 ◽  
Vol 11 ◽  
Author(s):  
Laura Carotti ◽  
Luuk Graamans ◽  
Federico Puksic ◽  
Michele Butturini ◽  
Esther Meinen ◽  
...  
Keyword(s):  
Light Intensity ◽  
Air Temperature ◽  
Dry Matter ◽  
Root Zone ◽  
Incident Light ◽  
Photon Flux ◽  
Dry Matter Content ◽  
Fresh Weight ◽  
Root Zone Temperature ◽  
Zone Temperature

This study analyzed interactions among photon flux density (PPFD), air temperature, root-zone temperature for growth of lettuce with non-limiting water, nutrient, and CO2 concentration. We measured growth parameters in 48 combinations of a PPFD of 200, 400, and 750 μmol m–2 s–1 (16 h daylength), with air and root-zone temperatures of 20, 24, 28, and 32°C. Lettuce (Lactuca sativa cv. Batavia Othilie) was grown for four cycles (29 days after transplanting). Eight combinations with low root-zone (20 and 24°C), high air temperature (28 and 32°C) and high PPFD (400 and 750 μmol m–2 s–1) resulted in an excessive incidence of tip-burn and were not included in further analysis. Dry mass increased with increasing photon flux to a PPFD of 750 μmol m–2 s–1. The photon conversion efficiency (both dry and fresh weight) decreased with increasing photon flux: 29, 27, and 21 g FW shoot and 1.01, 0.87, and 0.76 g DW shoot per mol incident light at 200, 400, and 750 μmol m–2 s–1, respectively, averaged over all temperature combinations, following a concurrent decrease in specific leaf area (SLA). The highest efficiency was achieved at 200 μmol m–2 s–1, 24°C air temperature and 28°C root-zone temperature: 44 g FW and 1.23 g DW per mol incident light. The effect of air temperature on fresh yield was linked to all leaf expansion processes. SLA, shoot mass allocation and water content of leaves showed the same trend for air temperature with a maximum around 24°C. The effect of root temperature was less prominent with an optimum around 28°C in nearly all conditions. With this combination of temperatures, market size (fresh weight shoot = 250 g) was achieved in 26, 20, and 18 days, at 200, 400, and 750 μmol m–2 s–1, respectively, with a corresponding shoot dry matter content of 2.6, 3.8, and 4.2%. In conclusion, three factors determine the “optimal” PPFD: capital and operational costs of light intensity vs the value of reducing cropping time, and the market value of higher dry matter contents.

scholarly journals Photosynthetic Responses of Creeping Bentgrass to Reduced Root-zone Temperatures at Supraoptimal Air Temperature

2002 ◽  
Vol 127 (5) ◽  
pp. 754-758 ◽  
Author(s):  
Qingzhang Xu ◽  
Bingru Huang ◽  
Zhaolong Wang
Keyword(s):  
Soil Temperature ◽  
Chlorophyll Content ◽  
Air Temperature ◽  
Root Zone ◽  
Creeping Bentgrass ◽  
Rubisco Activity ◽  
Root Zone Temperature ◽  
Single Leaf ◽  
Soil Temperatures ◽  
Zone Temperature

High air and soil temperatures are major factors limiting growth of cool-season grasses. A previous study by the authors reported that a soil temperature reduction of only 3 °C when air temperature was maintained at 35 °C significantly improved shoot and root growth of creeping bentgrass [Agrostis stolonifera L. var. palustris (Huds.) Farw. (syn. A. palustris Huds.)]. This study was designed to investigate the responses of photosynthetic activities of creeping bentgrass to lowered root-zone temperatures from the supraoptimal level when shoots were exposed to high air temperature. Two cultivars of creeping bentgrass, `L-93' and `Penncross', were exposed to the following air/root-zone temperature regimes in growth chambers and water baths: 1) optimal air and soil temperatures (20/20 °C, control); 2) lowering soil temperature by 3, 6, and 11 °C from 35 °C at high air temperatures (35/32, 35/29, and 35/24 °C); and 3) high air and soil temperatures (35/35 °C). Soil temperature was reduced from 35 °C by circulating cool water (18 °C) in water baths at variable flow rates. Both cultivars had similar responses to high or low root-zone temperatures with high air temperature. High air and root-zone temperatures caused significant reductions in canopy photosynthetic rate (Pcanopy), single-leaf photosynthetic rate (Pleaf), leaf chlorophyll content, photochemical efficiency (Fv/Fm), and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, beginning on day 1 of high air and soil temperature stress for Pcanopy and Pleaf, and day 7 for chlorophyll content, Fv/Fm, and Rubisco activity. The 3 °C reduction in root-zone temperature at high air temperature had no effect on those photosynthetic parameters, except chlorophyll content. Reducing root-zone temperature by 6 °C or 11 °C while maintaining air temperature at 35 °C significantly improved Pcanopy, Poleaf, leaf chlorophyll content, Fv/Fm, and Rubisco activity. Single leaf photosynthetic rate at 35/24 °C was not different from the control level, but Pcanopy at 35/24 °C was lower than the control level. A reduction in root-zone temperature enhanced canopy and single-leaf photosynthetic capacity even though shoots were exposed to supraoptimal air temperature, which could contribute to improved turfgrass growth.

scholarly journals `Rotundifolia' Holly Growth and Nitrogen Accumulation Influenced by Supraoptimal Root-zone Temperatures

HortScience ◽  
1991 ◽  
Vol 26 (11) ◽  
pp. 1387-1388 ◽  
Author(s):  
Thomas H. Yeager ◽  
Rebecca H. Harrison ◽  
Dewayne L. Ingram
Keyword(s):  
Root Zone ◽  
Dry Weight ◽  
N Fertilization ◽  
Sand Culture ◽  
Nitrogen Accumulation ◽  
N Accumulation ◽  
Root Zone Temperature ◽  
Root Zones ◽  
Application Rates ◽  
Zone Temperature

Ilex crenata Thunb. `Rotundifolia' grown in sand culture with the root zone at 40C for 6 hours daily had smaller root and shoot dry weights after 6 weeks than plants grown with root zones at 28 or 34C. Root and shoot N accumulation (milligrams N per gram of dry weight) decreased when root-zone temperatures were increased from 28 to 40C and plants were fertilized twice dally with either 75, 150, or 225 mg N/liter. Nitrogen application rates of 150 or 225 mg·liter-1 resulted in increased root and shoot N accumulation for plants grown with root zones at either 28, 34, or 40C compared with the 75 mg N/liter treatment. Increased N fertilization rates did not alleviate reduced plant growth due to the high root-zone temperature.

scholarly journals Changes of root zone temperature, growth and productivity of broccoli cultivated with coloured plastic mulches

2020 ◽  
Vol 66 (No. 3) ◽  
pp. 112-121
Author(s):  
Harby Mostafa ◽  
El-Sayed Khater ◽  
Ramy Hamouda
Keyword(s):  
Root Zone ◽  
Winter Season ◽  
Shoot Length ◽  
Fresh Weight ◽  
Root Volume ◽  
Root Zone Temperature ◽  
Temperature Growth ◽  
Black And White ◽  
Free Treatment ◽  
Zone Temperature

The main aim is to find out the influence of using coloured plastic mulches (blue, white, green, red, black and white on black) compared with a mulch-free treatment on the root zone temperature, growth and productivity of broccoli. The results indicated that the highest and lowest mean root zone temperatures were recorded the in the dark-coloured mulches (blue, green, red and white on black) and in the light-coloured mulches (white), respectively, in both the winter and spring seasons. The average shoot length, leaf number and root volume of the broccoli for all the treatments was higher in the spring season compared with those of the winter season. The highest marketable head fresh weight values were 449.6 and 451.0 g found in the black mulch, while the lowest values were 391.4 and 397.5 g found in the winter and spring seasons for the red mulch, respectively. The N, P, K, Ca and Mg concentrations in the broccoli heads ranged from 2.0 to 2.8%, 0.9 to 1.0%, 2.7 to 3.6%, 1.9 to 5.9% and 0.5 to 0.89%, respectively, for all the treatments.

scholarly journals Photosynthesis and Root Respiration in Ilex crenata `Rotundifolia' at Supraoptimal Root-zone Temperatures

HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 535-537
Author(s):  
William J. Foster ◽  
Dewayne L. Ingram ◽  
Terril A. Nell
Keyword(s):  
Root Respiration ◽  
Root Zone ◽  
Stomatal Resistance ◽  
Controlled Environment ◽  
Stem Cuttings ◽  
Root Zone Temperature ◽  
Electric System ◽  
Root Zones ◽  
Respiration Rates ◽  
Zone Temperature

Rooted stem cuttings of Ilex crenata Thunb. `Rotundifolia' were grown in a controlled-environment growth chamber. Root-zone temperatures were controlled with an electric system. Shoot carbon exchange and root respiration rates were determined in response to root-zone temperatures of 28, 32, 36, and 40C for 6 hour·day–1 for 7 days. Photosynthesis was decreased by root zones ≥ 32C, while root respiration increased with increasing root-zone temperature. Decreased photosynthetic rates were not due to increased stomatal resistance.

scholarly journals Elevated Air Temperatures Cause Foliar Bleaching of Ivy Geranium ‘Beach’ and ‘Butterfly’

HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 411-415 ◽  
Author(s):  
Ritu Dhir ◽  
Richard L. Harkess ◽  
Guihong Bi
Keyword(s):  
Root Zone ◽  
Foliar Spray ◽  
Weight Ratio ◽  
Dry Weight ◽  
Fresh Weight ◽  
Root Zone Temperature ◽  
Iron Chelate ◽  
Air Temperatures ◽  
Ivy Geranium ◽  
Zone Temperature

Bleaching of the youngest leaves of actively growing ivy geranium (Pelargonium peltatum L.) develops as the temperature increases from late spring to summer in the southeastern United States. Heat stress-induced iron deficiency has been suspected as causing this disorder. Ivy geranium ‘Beach’ (bleaching-resistant) and ‘Butterfly’ (bleaching-susceptible) were grown for 8 weeks at 24 or 31 °C average root-zone temperature and iron chelate (Fe-EDDHA, 6% Fe) was applied at 0 mg Fe (control), 0.54 mg Fe foliar spray, 1.08 mg Fe foliar spray, 54 mg Fe drench, or 108 mg Fe drench per plant at 30-day intervals. In a second experiment, ivy geranium ‘Beach’ and ‘Butterfly’ plants were grown for 6 weeks at 28 °C day/16 °C night or 36 °C day/22 °C night average air temperatures and iron chelate (Fe-EDDHA, 6% Fe) was applied at 0 mg (control) or 27 mg Fe soil drench per pot at 15-day intervals. No bleaching was observed as a result of elevated root-zone temperatures. High levels of Fe-chelate suppressed growth reducing fresh weight, dry weight, and fresh-to-dry-weight ratio in ‘Butterfly’. Elevated air temperatures severely reduced plant growth, leaf area, fresh weight, and dry weight in both cultivars. Elevated air temperature reduced chlorophyll a, carotenoids, and pheophytins in ‘Butterfly’ but not in ‘Beach’. Fe-chelate application had no effect at ambient temperature but increased chlorophyll to carotenoids ratio (Chl:Caro) at elevated air temperatures in ‘Butterfly’. Therefore, elevated air temperatures were determined to be the cause of bleaching in ivy geranium.

scholarly journals Influence of Root-zone Temperature on Growth of Ailanthus altissima (Mill.) Swingle

1989 ◽  
Vol 7 (2) ◽  
pp. 79-82
Author(s):  
William R. Graves ◽  
Michael N. Dana ◽  
Robert J. Joly
Keyword(s):  
Gas Exchange ◽  
Root Zone ◽  
Leaf Gas Exchange ◽  
Stem Length ◽  
Ailanthus Altissima ◽  
Root Zone Temperature ◽  
Root Zones ◽  
Shoot Ratio ◽  
Diffusive Resistance ◽  
Zone Temperature

Abstract Growth of tree-of-heaven (Ailanthus altissima (Mill.) Swingle) seedlings was evaluated during a 28-day exposure to constant root-zone temperatures of 18°, 24°, 30°, and 36°C (64°,75°, 86°, and 97°F). Leaf area, stem length, root-to-shoot ratio, and shoot and root dry weights were greatest among plants with 24°C (75°F) root zones. Diminished growth among plants at high root-zone temperatures was associated with reduced leaf conductance. After 14 days of treatment, leaf diffusive resistance of plants in the 36°C (97°F) regime was eight times greater than that of plants with 24°C (75°F) root zones. Regulation of leaf gas exchange among plants with 36°C (97°F) root zones probably contributed to the maintenance of moderate leaf water potentials but limited the fixation of carbon necessary to sustain growth.

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