Evidence for nonstomatal inhibition of net photosynthesis in rapidly dehydrated shoots of Populus

1986 ◽  
Vol 16 (6) ◽  
pp. 1371-1375 ◽  
Author(s):  
G. Scarascia-Mugnozza ◽  
T. M. Hinckley ◽  
R. F. Stettler
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Net Photosynthetic Rate ◽  
Photosynthetic Rate ◽  
Net Photosynthesis ◽  
Volume Shrinkage ◽  
Sharp Reduction ◽  
Stomatal Behaviour ◽  
Net Assimilation ◽  
Protoplast Volume

Results are presented on the decline of net photosynthesis during the application of rapid water stress to excised shoots of different Populus L. clones. Six clones were selected from the species Populustrichocarpa Torr. & Gray, Populusdeltoides Bartr., and from the hybrid Populustrichocarpa × Populusdeltoides, taking into account the differences in stomatal behaviour between and within these species. The two most productive P. trichocarpa clones and the hybrid clone, characterized by a reduced ability to close stomata during leaf desiccation, showed, nevertheless, a sharp reduction of net photosynthesis at water potentials lower than −1.5 MPa. In contrast, the inhibition of net assimilation in the P. deltoides clone, caused by water stress, was accompanied by a reduction in stomatal conductance. In all studied clones the decrease in net photosynthetic rate followed closely the point of turgor loss of the leaves, indicating a possible relationship between nonstomatal inhibition of photosynthesis and protoplast volume shrinkage.

Effect of Water Stress on Photosynthetic Parameters of Soybean (Glycine max) and Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Philip H. Munger ◽  
James M. Chandler ◽  
J. Tom Cothren
Keyword(s):  
Glycine Max ◽  
Water Stress ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Net Photosynthetic Rate ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Abutilon Theophrasti ◽  
Leaf Water ◽  
Photosynthetic Parameters

Greenhouse experiments were conducted to elucidate the effects of water stress on photosynthetic parameters of soybean [Glycine max(L.) Merr. ‘Hutton′] and velvetleaf (Abutilon theophrastiMedik. # ABUTH). Stomatal conductance of both species responded curvilinearly to reductions in leaf water potential. At leaf water potentials less negative than −2.5 MPa, stomatal conductance, net photosynthetic rate, and transpiration rate were greater in velvetleaf than in soybean. Soybean photosynthetic rate was linearly related to stomatal conductance. Velvetleaf photosynthetic rate increased linearly with stomatal conductances up to 1.5 cm s–1; however, no increase in photosynthetic rate was observed at stomatal conductances greater than 1.5 cm s–1, indicating nonstomatal limitations to photosynthesis. As water stress intensified, stomatal conductance, photosynthetic rate, and transpiration of velvetleaf declined more rapidly than in soybean.

Effects of water stress preconditioning on gas exchange and water relations of Populusdeltoides clones

1993 ◽  
Vol 23 (7) ◽  
pp. 1291-1297 ◽  
Author(s):  
G. Michael Gebre ◽  
Michael R. Kuhns
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Net Photosynthetic Rate ◽  
Osmotic Adjustment ◽  
Net Photosynthesis ◽  
Predawn Leaf Water Potential ◽  
Eastern Cottonwood ◽  
Control Net

The effect of water stress preconditioning on gas exchange was investigated in greenhouse-grown eastern Cottonwood (Populusdeltoides Bartr.). Two clones from southern Ohio (Ohio Red) and eastern Nebraska (Platte) were selected based on their differences in dehydration tolerance. Plants were either watered every day (control) or preconditioned by watering every 3 (TRT 1) or 4 days (TRT 2). After three dry–wet cycles (TRT 2), predawn leaf water potential (Ψw) of Ohio Red was −0.32 MPa; net photosynthesis and stomatal conductance were reduced to 13 and 9% of control, respectively. Eighteen hours after rewatering, photosynthesis recovered (103% of control), while stomatal conductance was 60% of control. Net photosynthesis of Platte was reduced to 43% and stomatal conductance to 32% of control (Ψw−0.21 MPa), and neither recovered fully when rewatered. After six dry–wet cycles (TRT 2), net photosynthesis of Ohio Red was reduced by 50%, though Ψw was −0.48 MPa. Clones showed an osmotic adjustment of −0.2 MPa after three (Platte) and six cycles (Ohio Red). When all preconditioned plants were stressed for 10 days, Ψw was −1.05 MPa and plants had negative net photosynthesis and no osmotic adjustment. Net photosynthetic rate of Ohio Red recovered (100% of control) on the second day of rewatering (stomatal conductance 68%), while Platte had not recovered (71%) by the fourth day (stomatal conductance 95%). These differences suggest that recovery of photosynthesis was limited mainly by stomatal factors in Ohio Red and nonstomatal factors in Platte. The preconditioning treatment also seems to have benefitted Ohio Red.

scholarly journals Response of in vitro Cultured Palm Oil Seedling Under Saline Condition to Elevated Carbon Dioxide and Photosynthetic Photon Flux Density

2012 ◽  
pp. 52-64
Author(s):  
Pet Roey Pascual ◽  
Krienkai Mosaleeyanon ◽  
Kanokwan Romyanon ◽  
Chalermpol Kirdmanee
Keyword(s):  
Stomatal Conductance ◽  
Net Photosynthetic Rate ◽  
Elevated Co2 ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Pigment Contents ◽  
Salinity Levels ◽  
Oil Palms ◽  
Ambient Co2

Salt stress elicits various physiological and growth responses of oil palm. A laboratory experiment was conducted to determine the responses of oil palms cultured in vitro under varying salinity levels (0, 85.5, 171.11, 342.21 and 684.43 mM NaCl) to elevated CO2 (1000 μmol CO2/mol) and PPFD (100±5 μmol m-2s-1) in terms of growth characteristics, pigment contents and photosynthetic abilities. After 14 days of culture, net photosynthetic rate (μmol CO2 m-2s-1) of oil palms across varying salinity levels was 5.33 times higher than those cultured under ambient CO, (380±100 Mmol CO2/mol) and PPFD (50±5 μmol m-2s -1). At increased net photosynthetic rate (elevated CO2 and PPFD), despite having no significant difference in pigment contents (chlorophyll a, chlorophyll b, total chlorophyll and carotenoid) between different CO2 and PPFD levels, dry weight and percent dry matter were 0.26 and 0.11 times higher, respectively, as compared to those cultured under ambient CO2 and PPFD. In the same elevated CO2 and PPFD level, across all salinity levels, stomatal conductance was 0.30 times lower than those cultured under ambient CO2 and PPFD. At reduced stomatal conductance (elevated CO2 and PPFD), transpiration rate was also reduced by 0.30 times. Thus with increased net photosynthetic rate and reduced transpiration rate, water use efficiency was increased by 7.22 times, across all salinity levels, than those cultured at ambient CO2 and PPFD. These were considered essential for NaCl produces iso-osmotic stress.

scholarly journals Effects of the reciprocal grafting on the photosynthesis of two genotypes tomato offspring under selenium stress

2019 ◽  
Vol 136 ◽  
pp. 07008
Author(s):  
Shiyao Shan ◽  
Huizhong Luo ◽  
Jinpeng Zhu ◽  
Zhiyu Li ◽  
Huanxiu Li
Keyword(s):  
Stomatal Conductance ◽  
Net Photosynthetic Rate ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Functional Activity ◽  
Theoretical Basis ◽  
Photosynthetic Capacity ◽  
Growth Characteristics ◽  
Cherry Tomato ◽  
Fresh Weight

To study the effects of the reciprocal grafting on the photosynthesis of two genotypes tomato offspring under selenium stress, red ball cherry tomato cherry 5-5-1 and yellow ball cherry tomato yellow RTY-3-2 post-grafting generation (red scion, red rootstock, yellow scion and yellow rootstock) and seedlings (red CK and yellow CK) planted in 10 mg·kg-1 selenium soil, and the pot experiment was carried out to study the effects of the reciprocal grafting on the growth characteristics and the photosynthesis of tomato offspring under selenium stress. The results showed that grafting increased the fresh weight of the organs of the offspring, the ratio of root to shoot, and the functional activity of the roots of the plants, which was conducive to the growth of tomato offspring. Simultaneously, it could effectively improve the photosynthetic capacity of grafted offspring leaves at the seedling stage. The grafted offspring of rootstocks had the best effect on improving the net photosynthetic rate, stomatal conductance and transpiration rate and stomatal conductance of tomato leaves, and decreased intercellular CO2 concentration. Among them, the best effect of yellow rootstock was to provide ideas and theoretical basis for the production of selenium-enriched tomatoes in the selenium-deficient areas in the future.

scholarly journals Mitigation of Osmotic Stress in Cotton for the Improvement in Growth and Yield through Inoculation of Rhizobacteria and Phosphate Solubilizing Bacteria Coated Diammonium Phosphate

2020 ◽  
Vol 12 (24) ◽  
pp. 10456
Author(s):  
Muhammad Majid ◽  
Muqarrab Ali ◽  
Khurram Shahzad ◽  
Fiaz Ahmad ◽  
Rao Muhammad Ikram ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Osmotic Stress ◽  
Net Photosynthetic Rate ◽  
Plant Height ◽  
Photosynthetic Rate ◽  
Diammonium Phosphate ◽  
Cotton Yield ◽  
Seed Cotton ◽  
Seed Cotton Yield ◽  
Boll Weight

Cotton (Gossypium hirsutum L.) is one of the major fiber crops. Its production is under threat due to scarcity of water resources under a changing climatic scenario. Limited water availability also decreases the uptake of phosphorus, and less uptake of phosphorus can deteriorate the quality attributes of cotton fiber. There is a need to introduce bio-organic amendments which can mitigate osmotic stress on a sustainable basis. Inoculation of rhizobacteria can play an imperative role in this regard. Rhizobacteria can not only improve the growth of roots but also enhance the availability of immobile phosphorus in soil. That is why the current experiment was conducted to explore and compare the efficacy of sole application of diammonium phosphate (DAP) over plant growth-promoting rhizobacteria (PGPR) and phosphorus solubilizing bacteria (PSB) coated DAP on growth and quality attributes of cotton under artificially induced osmotic stress at flowering stage. The impact of phosphorus levels was found to be significant on the plant height, leaf area, average boll weight, stomatal conductance, net photosynthetic rate, and seed cotton yield, while the irrigation effect was significant on all the parameters. The PGPR coated phosphorus performed better as compared to other treatments under normal irrigation and osmotic stress. Results showed that PGPR coated phosphorus increased by 29.47%, 21.01%, 41.11%, 32.73%, 15.63% and 22.89% plant height, average boll weight, stomatal conductance, net photosynthetic rate, fiber length, and seed cotton yield respectively. In conclusion, PGPR coated DAP can be helpful to get higher cotton productivity as compared to control and sole application of DAP under normal irrigation and osmotic stress.

Change in photosynthesis and water relations with age and season in Abiesamabilis

1984 ◽  
Vol 14 (1) ◽  
pp. 77-84 ◽  
Author(s):  
R. O. Teskey ◽  
C. C. Grier ◽  
T. M. Hinckley
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Relations ◽  
Net Photosynthesis ◽  
Carbon Gain ◽  
Xylem Water Potential ◽  
Needle Age ◽  
Stressful Environment ◽  
Competitive Success ◽  
One Year

Seasonal changes in water relations and net photosynthesis were measured over a year in current and 1-year-old foliage of Abiesamabilis (Dougl.) Forbes, a subalpine conifer. Responses were compared with maximum rates achieved in older foliage. Current-year foliage developed slowly during the growing season. Although growth began on 22 June, highest rates of stomatal conductance and net photosynthesis did not occur until September and October. One-year-old foliage had the highest rates of net photosynthesis (12.9 mg CO2•dm−2•h−1) and stomatal conductance (3.1 mm•s−1) during the summer. Net photosynthesis decreased with needle age, but foliage as old as 7 years had rates of net photosynthesis as high as 5.0 mg CO2•dm−2•h−1. There was no evidence of photosynthetic adjustment to seasonal change in temperature. The optimum temperature for photosynthesis remained at 15 ± 1.5 °C throughout the year. No water stress was observed during the summer. Xylem water potential never decreased below −1.65 MPa and was always well above the turgor loss point. The lack of any apparent water stress, combined with photosynthetic characteristics, indicated that summer was the most important season for carbon gain. These results also suggested that a strategy for competitive success by Abiesamabilis in this cold, stressful environment is minimum dependence on the carbon gain of any individual age-class of foliage. Instead trees rely on the combined photosynthetic capacity of many years of foliage.

scholarly journals Orange Rust Effects on Leaf Photosynthesis and Related Characters of Sugarcane

Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 640-647 ◽  
Author(s):  
Duli Zhao ◽  
Neil C. Glynn ◽  
Barry Glaz ◽  
Jack C. Comstock ◽  
Sushma Sood
Keyword(s):  
Stomatal Conductance ◽  
Quantum Yield ◽  
Net Photosynthetic Rate ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Carbon Fixation ◽  
Dark Respiration ◽  
Western Hemisphere ◽  
Maximum Quantum Yield ◽  
Leaf Photosynthesis

Orange rust of sugarcane (Saccharum spp. hybrids), caused by Puccinia kuehnii, is a relatively new disease in the Western Hemisphere that substantially reduces yields in susceptible sugarcane genotypes. The objective of this study was to determine the physiological mechanisms of orange rust–induced reductions in sugarcane growth and yield by quantifying effects of the disease on leaf SPAD index (an indication of leaf chlorophyll content), net photosynthetic rate, dark respiration, maximum quantum yield of CO2 assimilation, carbon fixation efficiency, and the relationships between these leaf photosynthetic components and rust disease ratings. Plants growing in pots were inoculated with the orange rust pathogen using a leaf whorl inoculation method. A disease rating was assigned using a scale from 0 to 4 with intervals of 0.5. At disease ratings ≥2, the rust-infected leaf portion of inoculated plants showed significant reductions in SPAD index, maximum quantum yield, carbon fixation efficiency, stomatal conductance, leaf transpiration rate, and net photosynthetic rate; but the rusted portion of the infected leaves had increased intercellular CO2 concentration and leaf dark respiration rate. Although leaf SPAD index, photosynthetic rate, stomatal conductance, and transpiration rate at the rust-infected portion decreased linearly with increased rust rating, the effect of orange rust on photosynthetic rate was much greater than that on stomatal conductance and transpiration. Unlike earlier reports on other crops, reduction in leaf photosynthesis by orange rust under low light was greater than that under high light conditions. These results help improve the understanding of orange rust etiology and physiological bases of sugarcane yield loss caused by orange rust.

Water relations, photosynthetic capacity, and root/shoot partitioning of photosynthate as determinants of productivity in hybrid poplar

1989 ◽  
Vol 67 (6) ◽  
pp. 1689-1697 ◽  
Author(s):  
T. J. Tschaplinski ◽  
T. J. Blake
Keyword(s):  
Net Photosynthetic Rate ◽  
Biomass Production ◽  
Photosynthetic Rate ◽  
Populus Deltoides ◽  
Hybrid Poplar ◽  
Net Photosynthesis ◽  
Unit Leaf ◽  
Vigorous Growth ◽  
The Difference ◽  
Causal Sequence

Physiological determinants of productivity, including net photosynthesis, root/shoot partitioning of photosynthate, and leaf retention were investigated for three Populus deltoides Bartr. × nigra L. (DN 2, DN 22, DN 15) and two P. balsamifera L. × deltoides Bartr. (Jackii 4, Jackii 7) hybrids. Performance of the different hybrids was compared under controlled greenhouse conditions and in the field. There was a 2.4-fold difference in biomass production between the faster growing DN 2 and the slower growing DN 15 after 100 days growth in the greenhouse, and a 1.5-fold difference after the 1st year's growth in the field. When coppice regrowth of the two Jackii hybrids was compared after 143 days under field conditions, the biomass production of Jackii 4 was 2.2 times that of Jackii 7 and net photosynthetic rate per unit leaf area was 50 % higher than that of Jackii 7 over most of the summer. Many physiological and morphological factors contributed to the more vigorous growth of coppice DN 2 and Jackii 4. These included vigorous initial root growth relative to shoot growth, the ability to maintain higher xylem pressure potentials, net photosynthetic rate, and transpiration rate. These factors may have delayed leaf senescence and late-season photosynthetic decline of older leaves until later in the growing season. The possible causal sequence of physiological events contributing to the difference in productivity and the use of these factors for the early selection of productive hybrids or genotypes are discussed.

scholarly journals Gas exchanges of melon under water stress in the Submedium region of the São Francisco River Valley

2019 ◽  
Vol 41 (1) ◽  
pp. 42686 ◽  
Author(s):  
Daniel Vieira Amorim ◽  
Alessandro Carlos Mesquita ◽  
Lígia Borges Marinho ◽  
Vanuza De Souza ◽  
Saulo De Tarso Aidar ◽  
...  
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Dry Matter ◽  
Block Design ◽  
Net Photosynthesis ◽  
River Valley ◽  
Sao Francisco River ◽  
Randomized Block Design ◽  
São Francisco River ◽  
Current Scenario

The current scenario of increased water scarcity is due to climate change and directly affects food production. It is thus necessary to develop strategies to mitigate the impacts of low water availability. Therefore, the goal of the present study is to evaluate the physiological behaviour of melon cultivars under water stress. The experiment was conducted in a protected environment in the experimental Submedium region of the São Francisco River Valley in the period ranging from October to December. In this study, we used the melon cultivars 'Amarelo' and 'Piel de Sapo'. The experiment was conducted in a randomized block design with three replicates that were subdivided into plots, where the plots were comprised of four irrigation rates (50, 75, 100, and 125% of crop evapotranspiration – CET), subplots were comprised of the two melon cultivars, and sub-subplots were comprised of samplings for physiological analyses (15, 30, and 45 days after transplanting). The parameters evaluated were stomatal conductance, transpiration, net photosynthesis, relationship CI/CA, and accumulated dry matter. Water stress reduced the stomatal conductance, transpiration, net photosynthesis, CI/CA, and accumulated dry matter. 'Piel de Sapo' showed a higher photosynthetic adjustment than 'Amarelo' melon due to the gas exchange behaviour of the former, and it was, therefore, more tolerant to water stress.

scholarly journals Reassessing the Role of Potassium in Tomato Grown with Water Shortages

Horticulturae ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 20
Author(s):  
Anna De Luca ◽  
Mireia Corell ◽  
Mathilde Chivet ◽  
M. Angeles Parrado ◽  
José M. Pardo ◽  
...  
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Photosynthetic Rate ◽  
Yield Reduction ◽  
Higher Plant ◽  
Water Shortages ◽  
Great Yield ◽  
Fruit Setting ◽  
K Concentration ◽  
Biomass Partition

Potassium (K) is closely related to plant water uptake and use and affects key processes in assimilation and growth. The aim of this work was to find out to what extent K supply and enhanced compartmentation might improve water use and productivity when tomato plants suffered from periods of water stress. Yield, water traits, gas exchange, photosynthetic rate and biomass partition were determined. When plants suffered dehydration, increasing K supply was associated with reduction in stomatal conductance and increased water contents, but failed to protect photosynthetic rate. Potassium supplements increased shoot growth, fruit setting and yield under water stress. However, increasing the K supply could not counteract the great yield reduction under drought. A transgenic tomato line with enhanced K uptake into vacuoles and able to reach higher plant K contents, still showed poor yield performance under water stress and had lower K use efficiency than the control plants. With unlimited water supply (hydroponics), plants grown in low-K showed greater root hydraulic conductivity than at higher K availability and stomatal conductance was not associated with leaf K concentration. In conclusion, increasing K supply and tissue content improved some physiological features related to drought tolerance but did not overcome yield restrictions imposed by water stress.

Sign in / Sign up

Export Citation Format

Share Document