Photosynthesis and Transpiration in Dicotyledonous Plants. II. Expanding and Senescing Leaves of Soybean

1976 ◽  
Vol 3 (2) ◽  
pp. 257 ◽  
Author(s):  
RG Woodward ◽  
HM Rawson
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Vapour Pressure Deficit ◽  
Net Photosynthesis ◽  
Unit Leaf ◽  
Efficiency Parameter ◽  
Dicotyledonous Plants ◽  
History Of ◽  
Use Efficiency ◽  
Soybean Leaves

The history of net photosynthesis and transpiration per unit leaf area was determined for intact soybean leaves from their unfolding to senescence during flowering and pod filling on untreated (podded) and partially depodded plants growing in a glasshouse. Leaf diffusive resistances to CO2 were calculated and a water use efficiency parameter was derived (net mass of carbon dioxide fixed per unit mass of water transpired per millibar vapour pressure deficit). Net photosynthesis and transpiration behaved similarly through all stages of leaf development. A number of peaks were evident in these parameters. The first was associated with leaf expansion and occurred when the leaf reached its maximum area. The second peak coincided with flowering of the plant and later peaks occurred during pod filling. Stomatal and mesophyll resistances also exhibited similar behaviour during the life of the leaf; the possible causes of this linkage are discussed. Water use efficiency increased rapidly up to the time of full lamina expansion. Thereafter, it rose slowly or remained stable until leaf senescence approached, when the efficiency declined. Net photosynthesis and transpiration of leaves were very similar in both podded and partially depodded plants. It appears that to prevent a shortage of assimilate during flowering and pod filling, photosynthesis may be maintained or increased in some leaves and the response is not related to the number of pods available for filling. The increases in photosynthesis were correlated with both higher stomatal and mesophyll conductances. Mechanisms by which the plant may control leaf photosynthesis are discussed.

scholarly journals Agronomic Biofortification of Cayenne Pepper Cultivars with Plant Growth-Promoting Rhizobacteria and Chili Residue in a Chinese Solar Greenhouse

2021 ◽  
Vol 9 (11) ◽  
pp. 2398
Author(s):  
Ibraheem Olamide Olasupo ◽  
Qiuju Liang ◽  
Chunyi Zhang ◽  
Md Shariful Islam ◽  
Yansu Li ◽  
...  
Keyword(s):  
Plant Growth ◽  
Water Use Efficiency ◽  
Water Use ◽  
Bacillus Amyloliquefaciens ◽  
Net Photosynthesis ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting ◽  
Use Efficiency ◽  
Growth Promoting ◽  
Agronomic Biofortification

Agronomic biofortification of horticultural crops using plant growth-promoting rhizobacteria (PGPR) under crop residue incorporation systems remains largely underexploited. Bacillus subtilis (B1), Bacillus laterosporus (B2), or Bacillus amyloliquefaciens (B3) was inoculated on soil containing chili residue, while chili residue without PGPR (NP) served as the control. Two hybrid long cayenne peppers, succeeding a leaf mustard crop were used in the intensive cultivation study. Net photosynthesis, leaf stomatal conductance, transpiration rate, photosynthetic water use efficiency, shoot and root biomass, and fruit yield were evaluated. Derivatives of folate, minerals, and nitrate contents in the pepper fruits were also assessed. B1 elicited higher net photosynthesis and photosynthetic water use efficiency, while B2 and B3 had higher transpiration rates than B1 and NP. B1 and B3 resulted in 27–36% increase in pepper fruit yield compared to other treatments, whereas B3 produced 24–27.5% and 21.9–27.2% higher 5-methyltetrahydrofolate and total folate contents, respectively, compared to B1 and NP. However, chili residue without PGPR inoculation improved fruit calcium, magnesium, and potassium contents than the inoculated treatments. ‘Xin Xian La 8 F1’ cultivar had higher yield and plant biomass, fruit potassium, total soluble solids, and total folate contents compared to ‘La Gao F1.’ Agronomic biofortification through the synergy of Bacillus amyloliquefaciens and chili residue produced better yield and folate contents with a trade-off in the mineral contents of the greenhouse-grown long cayenne pepper.

scholarly journals Trichoderma Enhances Net Photosynthesis, Water Use Efficiency, and Growth of Wheat (Triticum aestivum L.) under Salt Stress

2020 ◽  
Vol 8 (10) ◽  
pp. 1565 ◽  
Author(s):  
Abraham Mulu Oljira ◽  
Tabassum Hussain ◽  
Tatoba R. Waghmode ◽  
Huicheng Zhao ◽  
Hongyong Sun ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Net Photosynthesis ◽  
Photosynthetic Parameters ◽  
Wheat Cultivars ◽  
Salt Tolerant ◽  
Use Efficiency ◽  
Trichoderma Isolates

Soil salinity is one of the most important abiotic stresses limiting plant growth and productivity. The breeding of salt-tolerant wheat cultivars has substantially relieved the adverse effects of salt stress. Complementing these cultivars with growth-promoting microbes has the potential to stimulate and further enhance their salt tolerance. In this study, two fungal isolates, Th4 and Th6, and one bacterial isolate, C7, were isolated. The phylogenetic analyses suggested that these isolates were closely related to Trichoderma yunnanense, Trichoderma afroharzianum, and Bacillus licheniformis, respectively. These isolates produced indole-3-acetic acid (IAA) under salt stress (200 mM). The abilities of these isolates to enhance salt tolerance were investigated by seed coatings on salt-sensitive and salt-tolerant wheat cultivars. Salt stress (S), cultivar (C), and microbial treatment (M) significantly affected water use efficiency. The interaction effect of M x S significantly correlated with all photosynthetic parameters investigated. Treatments with Trichoderma isolates enhanced net photosynthesis, water use efficiency and biomass production. Principal component analysis revealed that the influences of microbial isolates on the photosynthetic parameters of the different wheat cultivars differed substantially. This study illustrated that Trichoderma isolates enhance the growth of wheat under salt stress and demonstrated the potential of using these isolates as plant biostimulants.

scholarly journals Management of Plant Physiology with Beneficial Bacteria to Improve Leaf Bioactive Profiles and Plant Adaptation under Saline Stress in Olea europea L.

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 57 ◽  
Author(s):  
Estrella Galicia-Campos ◽  
Beatriz Ramos-Solano ◽  
Mª. Belén Montero-Palmero ◽  
F. Javier Gutierrez-Mañero ◽  
Ana García-Villaraco
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Pigments ◽  
Soluble Sugars ◽  
Net Photosynthesis ◽  
Saline Stress ◽  
Plant Fitness ◽  
Ros Scavenging ◽  
Use Efficiency ◽  
Pruning Residues

Global climate change has increased warming with a concomitant decrease in water availability and increased soil salinity, factors that compromise agronomic production. On the other hand, new agronomic developments using irrigation systems demand increasing amounts of water to achieve an increase in yields. Therefore, new challenges appear to improve plant fitness and yield, while limiting water supply for specific crops, particularly, olive trees. Plants have developed several innate mechanisms to overcome water shortage and the use of beneficial microorganisms to ameliorate symptoms appears as a challenging alternative. Our aim is to improve plant fitness with beneficial bacterial strains capable of triggering plant metabolism that targets several mechanisms simultaneously. Our secondary aim is to improve the content of molecules with bioactive effects to valorize pruning residues. To analyze bacterial effects on olive plantlets that are grown in saline soil, photosynthesis, photosynthetic pigments, osmolytes (proline and soluble sugars), and reactive oxygen species (ROS)-scavenging enzymes (superoxide dismutase-SOD and ascorbate peroxidase-APX) and molecules (phenols, flavonols, and oleuropein) were determined. We found photosynthetic pigments, antioxidant molecules, net photosynthesis, and water use efficiency to be the most affected parameters. Most strains decreased pigments and increased osmolytes and phenols, and only one strain increased the antihypertensive molecule oleuropein. All strains increased net photosynthesis, but only three increased water use efficiency. In conclusion, among the ten strains, three improved water use efficiency and one increased values of pruning residues.

Effect of Leaf Position, Expansion and Age on Photosynthesis, Transpiration and Water Use Efficiency of Cotton

1980 ◽  
Vol 7 (1) ◽  
pp. 89 ◽  
Author(s):  
GA Constable ◽  
HM Rawson
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Dark Respiration ◽  
Vapour Pressure Deficit ◽  
Initial Slope ◽  
Photon Flux ◽  
Morphological Development ◽  
Leaf Position ◽  
Leaf Unfolding ◽  
Use Efficiency

Net photosynthesis, dark respiration and the response to photon flux density were measured on cotton leaves grown in a glasshouse. Leaves at four positions on the plant were examined from their unfolding until 70 days later. Photosynthesis and transpiration per unit of leaf area were unaffected by leaf position and, in all leaves, peak photosynthesis of about 110 ng CO2 cm-2 s-1 was attained 13-15 days after leaf unfolding, when the leaf was 75-90% of maximum area. Photosynthesis was maintained at this rate for only 12 days before declining linearly to values 20% of the maximum when leaves were 70 days old. Transpiration followed a similar pattern reaching a maximum of about 13 �g H2O cm-2 s-1 at 2 kPa vapour pressure deficit (VPD) at 13 days. Stomatal and internal conductances changed in parallel as leaves aged, with the consequence that internal CO2 concentration and water use efficiency remainedessentially constant at 220�ll-1 and 16.8 ng CO2 (�g H2O kPa VPD-1)-1 respectively. Youngest and oldest leaves saturated at lowest light levels (400-800 pE m-2 s-1) while 16-18- day-old leaves had light saturation at 1100 �E m-2 s-1. The initial slope of the light response curves increased as leaves expanded up to 10 days age then remained constant at 0.25 ng CO2 cm-2 (pE m-2)-1. Dark respiration reached a maximum of 1.5 ng CO2 mg-1 s-1 5 days after leaf unfolding, when leaf dry weight was increasing most rapidly. The relationship between the consistent pattern of gas exchange with age and the pattern of morphological development is discussed, along with internal factors associated with age-dependent photosynthesis.

Physiological acclimation of Pinus flexilis to drought stress on contrasting slope aspects in Waterton Lakes National Park, Alberta, Canada

2009 ◽  
Vol 39 (3) ◽  
pp. 629-641 ◽  
Author(s):  
Matthew G. Letts ◽  
Kevin N. Nakonechny ◽  
K. Eric Van Gaalen ◽  
Cyndi M. Smith
Keyword(s):  
Gas Exchange ◽  
Water Use ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Vapour Pressure Deficit ◽  
Net Photosynthesis ◽  
Pinus Flexilis ◽  
Limber Pine ◽  
Use Efficiency ◽  
Physiological Acclimation

Photosynthetic gas-exchange characteristics were measured in Pinus flexilis James (limber pine) during two drought years in a xeric, subalpine ecosystem of the Rocky Mountains. Limber pine exhibited conservative water-use traits, including low specific leaf area, leaf nitrogen, stomatal conductance, transpiration (E), and light-saturated net photosynthesis (Amax), but exhibited high needle longevity, water-use efficiency (Amax/E), and stable carbon isotope composition. Net photosynthesis declined strongly with leaf-to-air vapour pressure deficit, resulting in a bimodal seasonal pattern of Amax. Although very little gas exchange was observed in late summer, photosynthetic activity extended into October. The avoidance of gas exchange during high atmospheric demand maximized whole-season water-use efficiency. Leaf temperature and leaf-to-air vapour pressure deficit were higher on south-facing slopes during both moderate (2006) and severe (2007) drought. Severe drought caused lower stomatal conductance and E on the southeast-facing slope, but neither Amax nor canopy reflectance indices differed among slope aspects. Although Amax was lower in 2007 than 2006, branch-length increment did not differ. Foliar stable carbon isotope composition was higher in needles produced in dry years but did not vary among slope aspects. These results indicate that physiological acclimation to water stress prevented among-aspect differences in Amax and that shoulder-season photosynthesis may become increasingly important in a warmer climate.

scholarly journals Agronomic performance and gaseous exchanges of the radish under saline stress and ascorbic acid application

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Ygor Henrique Leal ◽  
Leonardo Vieira de Sousa ◽  
Toshik Iarley Da Silva ◽  
Joana Gomes de Moura ◽  
Ana Gabriela Sousa Basílio ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Water Use Efficiency ◽  
Water Use ◽  
Irrigation Water ◽  
Foliar Application ◽  
Net Photosynthesis ◽  
Saline Stress ◽  
Agronomic Performance ◽  
Electrical Conductivities ◽  
Use Efficiency

The radish is a short-cycle vegetable that has excellent nutritional and medicinal properties. It is considered rustic, meaning it tolerates adverse conditions with the possibility of being irrigated with saline water, which creates stress. In this context, this study aimed to evaluate the effect of electrical conductivities in irrigation water and doses of ascorbic acid on the agronomic performance and gaseous exchanges of radishes. This experiment was carried out in a protected environment at the Agricultural Sciences Center of the Federal University of Paraíba, Areia, Paraíba (Brazil). The experiment design used randomized blocks with five doses of ascorbic acid (0.0, 0.29, 1.0, 1.71 and 2.0 mM) and five electrical conductivities in the irrigation water (0.5, 1.3, 3.25, 5.2 and 6.0 dS m-1), with four replicates. The growth, gas exchange and production were evaluated. The doses of ascorbic acid were not significant. The increase in the electrical conductivities of the irrigation water provided a reduction in the agronomic performance and gas exchanges, except for the net photosynthesis, water use efficiency and instantaneous carboxylation efficiency, which were not significant. There was a relationship between the net photosynthesis, transpiration, internal concentration of CO2 and water use efficiency and the stomatal conductance. The agronomic performance and gaseous exchanges of the radish culture were influenced by the salinity. The foliar application of ascorbic acid did not influence the agronomic yield and gaseous exchanges of the radishes at the tested doses.

scholarly journals Nitrogen and Light Affect Water Use and Water Use Efficiency of Zoysiagrass Genotypes Differing in Canopy Structure

HortScience ◽  
2011 ◽  
Vol 46 (4) ◽  
pp. 643-647 ◽  
Author(s):  
John E. Erickson ◽  
Kevin E. Kenworthy
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Water Conservation ◽  
Management Practices ◽  
Canopy Structure ◽  
N Fertilization ◽  
Unit Leaf ◽  
Daily Evapotranspiration ◽  
Use Efficiency ◽  
Water Use Rates

Irrigation of residential lawns represents one of the major uses of potable water in many regions. An increased understanding of physiological responses underlying effects of turfgrass genotypes and management practices on water use rates and water use efficiencies could contribute to water conservation. Thus, we evaluated the effects of nitrogen (N) fertilization (0.0 and 2.5 g·m−2) and light environment (full sun and 50% shade) on average daily evapotranspiration (ETAVE), daily ET per unit leaf area (ETLA), carbon exchange rate (CER), and water use efficiency (WUE) in upright (experimental TAES 5343-22) and prostrate (‘Empire’) zoysiagrasses (Zoysia japonica Steud.) during two repeated trials. Across all treatments, ETAVE was 4.0 and 5.4 mm·d−1 during Trials 1 and 2, respectively. In the upright-growing genotype, ETAVE was ≈10% greater than the prostrate genotype during Trial 1. Nitrogen fertilization increased water use by ≈20% compared with non-fertilized pots. However, N fertilization reduced ETLA and increased WUE. Thus, ETAVE was positively related with WUE. As a result, there was a tradeoff between ETAVE and WUE, indicating that efforts to achieve reductions in water use through low N fertilization or genotypes can be accomplished, but in some cases at the expense of using water less efficiently to assimilate carbon for plant growth processes. In turfgrass, reductions in growth and WUE might be acceptable to minimize water use, but vigor and quality need to be maintained.

Growth and yield response of barley and chickpea to water stress under three environments in southeast Queensland. III. Water use efficiency, transpiration efficiency and soil evaporation

1995 ◽  
Vol 46 (1) ◽  
pp. 49 ◽  
Author(s):  
s Thoma ◽  
S Fukai
Keyword(s):  
Water Stress ◽  
Water Use Efficiency ◽  
Water Use ◽  
Vapour Pressure Deficit ◽  
Soil Evaporation ◽  
Growth And Yield ◽  
Yield Response ◽  
Transpiration Efficiency ◽  
Canopy Development ◽  
Use Efficiency

Two cultivars of barley and one cultivar of chickpea were grown in both well-watered and water stress conditions in three experiments. Water use efficiency (biomass produced per unit evapotranspiration) was lower in chickpea than in barley, and between two barley cultivars it was higher in early-maturing Corvette than in late-maturing Triumph. These differences in water use efficiency were mostly related to the differences in transpiration efficiency (biomass produced per unit transpiration). The latter appeared to reflect the differences in biomass production under well-watered conditions, as similar differences were found in light use efficiency (biomass produced per unit of photosynthetically active radiation intercepted) among the three crops. Transpiration efficiency was inversely related to vapour pressure deficit of the air. In three experiments soil evaporation accounted for about 55% and 10-30% of total water use for chickpea and barley respectively during observation periods, when rainfall was excluded from the plots. Slow canopy development of chickpea was a reason for such a high proportion of soil evaporation, and this contributed to its lower water use efficiency compared to barley. The amount of radiation transmitted to the soil surface appeared to be an important factor determining soil evaporation, even when soil water was not fully available and limiting soil evaporation.

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