Mechanisms of Impairment of the Photosynthetic Apparatus in Intact Leaves by Ozone

1999 ◽  
Vol 54 (9-10) ◽  
pp. 824-829 ◽  
Author(s):  
Thomas Gerhard Reichenauer ◽  
Harald Romuald Bolhàr-Nordenkampf
Keyword(s):  
Plant Growth ◽  
Calvin Cycle ◽  
Photosynthetic Apparatus ◽  
Net Photosynthesis ◽  
Major Effect ◽  
Photochemical Reactions ◽  
Early Event ◽  
Lag Phase ◽  
Limiting Factor ◽  
Negative Consequences

Tropospheric ozone has been recognised as a limiting factor for plant growth since late fifties of our century. The decrease in the rate of light saturated net photosynthesis (Asat) was shown to be the major effect of ozone in leaves with negative consequences for plant growth and the development of plant communities. The reasons for the ozone-induced decrease in Asat are still under investigation. Possible mechanisms are an increasing stomatal limitation, an increase in mesophyll limitation including a reduction of the CO2 fixation in the Calvin cycle and an impairment of the photochemical reactions in the grana membranes of chloroplasts. We conclude from the reviewed literature and from our own experiments that a decrease in carboxylation efficiency (CE) seems to be an early event caused by ozone leading to a decrease in Asat. The loss in current photochemical capacity (Fv/Fm) appears with a lag phase of many days and therefore the loss is thought to be a secondary effect due to a decreased demand of ‘assimilatory power’

scholarly journals Morphological and Metabolite Responses of Potatoes under Various Phosphorus Levels and Their Amelioration by Plant Growth-Promoting Rhizobacteria

2021 ◽  
Vol 22 (10) ◽  
pp. 5162
Author(s):  
Leangsrun Chea ◽  
Birgit Pfeiffer ◽  
Dominik Schneider ◽  
Rolf Daniel ◽  
Elke Pawelzik ◽  
...  
Keyword(s):  
Amino Acids ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Shoot Biomass ◽  
Root Surface Area ◽  
Limiting Factor ◽  
P Availability ◽  
P Deficiency ◽  
Plant Growth Promoting ◽  
Growth Promoting

Low phosphorus (P) availability is a major limiting factor for potatoes. P fertilizer is applied to enhance P availability; however, it may become toxic when plants accumulate at high concentrations. Therefore, it is necessary to gain more knowledge of the morphological and biochemical processes associated with P deficiency and toxicity for potatoes, as well as to explore an alternative approach to ameliorate the P deficiency condition. A comprehensive study was conducted (I) to assess plant morphology, mineral allocation, and metabolites of potatoes in response to P deficiency and toxicity; and (II) to evaluate the potency of plant growth-promoting rhizobacteria (PGPR) in improving plant biomass, P uptake, and metabolites at low P levels. The results revealed a reduction in plant height and biomass 60–80% under P deficiency compared to P optimum. P deficiency and toxicity conditions also altered the mineral concentration and allocation in plants due to nutrient imbalance. The stress induced by both P deficiency and toxicity was evident from an accumulation of proline and total free amino acids in young leaves and roots. Furthermore, root metabolite profiling revealed that P deficiency reduced sugars by 50–80% and organic acids by 20–90%, but increased amino acids by 1.5–14.8 times. However, the effect of P toxicity on metabolic changes in roots was less pronounced. Under P deficiency, PGPR significantly improved the root and shoot biomass, total root length, and root surface area by 32–45%. This finding suggests the potency of PGPR inoculation to increase potato plant tolerance under P deficiency.

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.

Effects of AOC and Phosphorus on Bacterial Growth under Oligotrophic Condition (1)

2011 ◽  
Vol 138-139 ◽  
pp. 981-987
Author(s):  
Deng Ling Jiang ◽  
Guo Wei Ni ◽  
Yu Min Zhang
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Bacterial Growth ◽  
Water Samples ◽  
Phosphorus Concentration ◽  
Lag Phase ◽  
Limiting Factor ◽  
Bacterial Number ◽  
In The Beginning ◽  
Oligotrophic Condition

The effects of phosphorus and organic carbon on bacterial growth were investigated in the laboratory. The bacteria sampled from the drinking water network of Tianjin were inoculated into water samples with different content of phosphorus (0～15µg PO43--P/L) and assimilable organic carbon (10～200µgAOC/L). The inoculated water samples were incubated at 20°C. Bacterial growth was monitored in every 2 days in the beginning of cultivation and in every 4 days or more in the later of the cultivation. Results showed that Phosphorus had obvious promotion on bacterial growth, which included shortening the lag phase evidently, increasing the growth rate and the maximum cell count in stationary phase. Carbon can only increase bacterial number. Under oligotrophic condition，when ratio of AOC: P in nutrients of water was more than 100:5, phosphorus was the limiting factor of bacterial growth. The bacterial yield factors against phosphorus and AOC were 1.1×109CFU/µgP and 9.0×107CFU/µgAOC respectively. Phosphorus was more sensitive than AOC. When the phosphorus concentration was less than 0.7µg/L in water samples, it was very difficult for bacteria to obtain phosphorus, and then growth of bacteria was very slowly or in lag phase in the first nine days of incubation time. In drinking water with low concentration of phosphorus (<0.7µg/L) and disinfectants, bacterial regrowth may be controlled. The paper will be Narrated in two parts, “Effects of AOC and Phosphorus on Bacterial Growth under Oligotrophic Condition (1)” and “Effects of AOC and Phosphorus on Bacterial Growth under Oligotrophic Condition (2)”.

scholarly journals Effects of Waterlogging with Different Water Resources on Plant Growth and Tolerance Capacity of Four Herbaceous Flowers in a Bioretention Basin

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1619 ◽  
Author(s):  
Wen-Chi Yang ◽  
Kuan-Hung Lin ◽  
Chun-Wei Wu ◽  
Yu-Jie Chang ◽  
Yu-Sen Chang
Keyword(s):  
Plant Growth ◽  
Water Resource ◽  
Tap Water ◽  
Ornamental Plants ◽  
Net Photosynthesis ◽  
Photosynthesis Rate ◽  
Extreme Weather Events ◽  
Waterlogging Tolerance ◽  
Water Shortages ◽  
Narrow Leaf

Extreme weather events have increased due to climate change. Bioretention basins can effectively alleviate urban flooding by short-term water retention. Reclaimed water (RW) is considered an alternative water resource during water shortages. In this study, the abilities for waterlogging tolerance of four herbaceous flowers (angelonia, narrow-leaf zinnia, celosia, and medallion flower) are investigated to screen suitable ornamental plants for bioretention basins, and the influence of RW on the plants is also evaluated. All plants were treated with 10 days of waterlogging (electrical conductivity (EC) of tap water = 110.0 μS·cm−1) followed by a seven-day recovery. Angelonia (Angelonia salicariifolia Humb. & Bonpl) was not affected by waterlogging and showed the best performance, judged from the ornamental quality, photosynthesis rate, and leaf malondialdehyde (MDA) among the tested flowers. Photosynthesis of the narrow-leaf zinnia (Zinnia angustifolia Kunth) decreased during waterlogging but soon recovered after being drained. Celosia (Celosia argentea L.) and medallion flower (Melampodium paludosum Kunth) were significantly affected by waterlogging and did not recover after drainage, in terms of responses to both external and physiological reactions. Moreover, waterlogging by the simulated RW (EC = 542.4 μS·cm−1) did not have negative impacts on angelonia and narrow-leaf zinnia, due to the reduced leaf malondialdehyde concentration of angelonia and retarded the decline in the net photosynthesis rate of narrow-leaf zinnia. Thus, RW could be used as an alternative irrigation water resource for bioretention basins during the dry season to maintain plant growth.

Simultaneous Gas-Exchange and Fluorescence Measurements with Ozone-Fumigated Spruce

1994 ◽  
Vol 49 (11-12) ◽  
pp. 819-833
Author(s):  
Stefan Drenkard ◽  
Jürgen Maguhn ◽  
Dietmar Knoppik
Keyword(s):  
Gas Exchange ◽  
Calvin Cycle ◽  
Photosynthetic Apparatus ◽  
Early Summer ◽  
Assimilation Rate ◽  
Light Reaction ◽  
Fluorescence Measurements ◽  
Transport Chain ◽  
Short Time ◽  
Supply Information

A method was developed for carrying out gas-exchange and chlorophyll-fluorescence measurements simultaneously during fumigation of spruce twigs with peroxidic photooxidants. It is thus now possible to investigate how a pollutant affects distinct sectors of the photosynthetic apparatus of the plant: whereas fluorescence reveals any changes in the primary light reaction, CO2 gas-exchange measurements supply information about the biochemical reactions of the Calvin cycle. Results of short-time fumigation with 750 ppb ozone are presented here. Gas-exchange and fluorescence data are affected strongly in early summer, but not in autumn. The assimilation rate decreases significantly: primarily as a result of Rubisco activity and possibly because of direct inhibition of the electron-transport chain as well. Closure of the stomata leads to further reduction in the assimilation rate. Though no damage becomes visible on the needles, the perturbance of the photosynthetic apparatus caused by ozone fumigation is not reversible within 24 h.

scholarly journals Research Progress and Perspective on Drought Stress in Legumes: A Review

2019 ◽  
Vol 20 (10) ◽  
pp. 2541 ◽  
Author(s):  
Muhammad Nadeem ◽  
Jiajia Li ◽  
Muhammad Yahya ◽  
Alam Sher ◽  
Chuanxi Ma ◽  
...  
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Nutrient Uptake ◽  
Nutrient Management ◽  
Growth Parameters ◽  
Photosynthetic Apparatus ◽  
Net Photosynthesis ◽  
Research Progress ◽  
Drought Tolerant ◽  
The Impact

Climate change, food shortage, water scarcity, and population growth are some of the threatening challenges being faced in today’s world. Drought stress (DS) poses a constant challenge for agricultural crops and has been considered a severe constraint for global agricultural productivity; its intensity and severity are predicted to increase in the near future. Legumes demonstrate high sensitivity to DS, especially at vegetative and reproductive stages. They are mostly grown in the dry areas and are moderately drought tolerant, but severe DS leads to remarkable production losses. The most prominent effects of DS are reduced germination, stunted growth, serious damage to the photosynthetic apparatus, decrease in net photosynthesis, and a reduction in nutrient uptake. To curb the catastrophic effect of DS in legumes, it is imperative to understand its effects, mechanisms, and the agronomic and genetic basis of drought for sustainable management. This review highlights the impact of DS on legumes, mechanisms, and proposes appropriate management approaches to alleviate the severity of water stress. In our discussion, we outline the influence of water stress on physiological aspects (such as germination, photosynthesis, water and nutrient uptake), growth parameters and yield. Additionally, mechanisms, various management strategies, for instance, agronomic practices (planting time and geometry, nutrient management), plant growth-promoting Rhizobacteria and arbuscular mycorrhizal fungal inoculation, quantitative trait loci (QTLs), functional genomics and advanced strategies (CRISPR-Cas9) are also critically discussed. We propose that the integration of several approaches such as agronomic and biotechnological strategies as well as advanced genome editing tools is needed to develop drought-tolerant legume cultivars.

scholarly journals Bioactivity Study of the C60-L-Threonine Derivative for Potential Application in Agriculture

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Gayane G. Panova ◽  
Evgeny B. Serebryakov ◽  
Konstantin N. Semenov ◽  
Nikolay A. Charykov ◽  
Olga S. Shemchuk ◽  
...  
Keyword(s):  
Biological Activity ◽  
Plant Growth ◽  
Ultraviolet Radiation ◽  
Potential Application ◽  
Antioxidant Properties ◽  
Photosynthetic Apparatus ◽  
Stress Factors ◽  
Biological Study ◽  
Nonspecific Resistance ◽  
Pesticide Load

The present paper reports data on the biological activity of nanocompositions based on a C60-L-threonine (C60-Thr) derivative. These nanocompositions promote the nonspecific resistance of plants to the action of stress factors (ultraviolet radiation, pesticides, and phytopathogens). Additionally, we determined the perspectives of the C60-Thr adduct application in the cultivation of plants due to the decrease of the pesticide load on the environment. The biological study of C60-Thr revealed the plant growth-stimulating ability due to its influence on the photosynthetic apparatus activity and antioxidant properties.

scholarly journals Endophytic colonization of rice (Oryza sativa L.) by the diazotrophic bacterium Burkholderia kururiensis and its ability to enhance plant growth

2008 ◽  
Vol 80 (3) ◽  
pp. 477-493 ◽  
Author(s):  
Katherine A. Mattos ◽  
Vania L.M. Pádua ◽  
Alexandre Romeiro ◽  
Leticia F. Hallack ◽  
Bianca C. Neves ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Plant Growth ◽  
Bacterial Growth ◽  
Plant Development ◽  
Oryza Sativa L ◽  
Limiting Factor ◽  
Rice Grain ◽  
Diazotrophic Bacterium ◽  
Endophytic Colonization ◽  
Auxin Production

Burkholderia kururiensis is a diazotrophic bacterium originally isolated from a polluted aquifer environment and presents a high level of similarity with the rice endophyte "B. brasilensis" species. This work assessed the ability of B. kururiensis to endophytically colonize rice plantlets by monitoring different tissues of root-inoculated plants for the presence of bacterial growth in different media, electron microscopy and by 16S rDNA analysis. Observations of roots, stems and leaves of inoculated rice plantlets by electron microscopy revealed B. kururiensis colonization predominantly on root hair zones, demonstrating endophytic colonization primarily through the endodermis, followed by spreading into xylem vessels, a possible pathway leading to aerial parts. Although indifferent for the bacterial growth itself, addition of a nitrogen source was a limiting factor for endophytic colonization. As endophytic colonization was directly associated to an enhanced plant development, production of phytohormone auxin/indole-3-acetic acid by B. kururiensis was assayed with transgenic rice plantlets containing an auxin-responsive reporter (DR5-GUS). Our findings suggest the ability of auxin production by plant-associated B. kururiensis which may have a stimulatory effect on plant development, as evidenced by activation of DR5-GUS. We hereby demonstrate, for the first time, the ability of B. kururiensis to endophytically colonize rice, promoting both plant growth and rice grain yield.

scholarly journals Effects of Ca2+ and Mg2+ on the activity of pyruvate dehydrogenase phosphate phosphatase within toluene-permeabilized mitochondria

1987 ◽  
Vol 241 (2) ◽  
pp. 371-377 ◽  
Author(s):  
P J Midgley ◽  
G A Rutter ◽  
A P Thomas ◽  
R M Denton
Keyword(s):  
Adipose Tissue ◽  
Small Molecules ◽  
White Adipose Tissue ◽  
Pyruvate Dehydrogenase ◽  
Maximum Rate ◽  
Major Effect ◽  
Lag Phase ◽  
Inhibitory Effects ◽  
Highly Sensitive ◽  
Epididymal White Adipose Tissue

Mitochondria from rat epididymal white adipose tissue were made permeable to small molecules by toluene treatment and were used to investigate the effects of Mg2+ and Ca2+ on the re-activation of pyruvate dehydrogenase phosphate by endogenous phosphatase. Re-activation of fully phosphorylated enzyme after addition of 0.18 mM-Mg2+ showed a marked lag of 5-10 min before a maximum rate of reactivation was achieved. Increasing the Mg2+ concentration to 1.8 mM (near saturating) or the addition of 100 microM-Ca2+ resulted in loss of the lag phase, which was also greatly diminished if pyruvate dehydrogenase was not fully phosphorylated. It is concluded that, within intact mitochondria, phosphatase activity is highly sensitive to the degree of phosphorylation of pyruvate dehydrogenase and that the major effect of Ca2+ may be to overcome the inhibitory effects of sites 2 and 3 on the dephosphorylation of site 1. Apparent K0.5 values for Mg2+ and Ca2+ were determined from the increases in pyruvate dehydrogenase activity observed after 5 min. The K0.5 for Mg2+ was diminished from 0.60 mM at less than 1 nM-Ca2+ to 0.32 mM at 100 microM-Ca2+; at 0.18 mM-Mg2+, the K0.5 for Ca2+ was 0.40 microM. Ca2+ had little or no effect at saturating Mg2+ concentrations. Since effects of Ca2+ are readily observed in intact coupled mitochondria, it follows that Mg2+ concentrations within mitochondria are sub-saturating for pyruvate dehydrogenase phosphate phosphatase and hence less than 0.5 mM.

Involvement ofgacSandrpoSin enhancement of the plant growth-promoting capabilities ofEnterobacter cloacaeCAL2 and UW4

2001 ◽  
Vol 47 (8) ◽  
pp. 698-705 ◽  
Author(s):  
Saleema S Saleh ◽  
Bernard R Glick
Keyword(s):  
Plant Growth ◽  
Pseudomonas Fluorescens ◽  
Indoleacetic Acid ◽  
Acc Deaminase ◽  
Enterobacter Cloacae ◽  
Lag Phase ◽  
Plant Growth Promoting Bacteria ◽  
Multicopy Plasmid ◽  
Plant Growth Promoting ◽  
Growth Promoting

The plant growth-promoting bacteria Enterobacter cloacae CAL2 and UW4 were genetically transformed with a multicopy plasmid containing an rpoS or gacS gene from Pseudomonas fluorescens. The transformed strains were compared with the nontransformed strains for growth, indoleacetic acid (IAA) production, antibiotic production, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, siderophore production, cell morphology, and the ability to promote canola root elongation. All transformed strains had a longer lag phase, were slower in reaching stationary phase, and attained a higher cell density than the nontransformed strains. Transformation resulted in cells that were significantly shorter than the nontransformed cells. The transformed strains also produced significantly more IAA than the nontransformed strains. Introduction of rpoS or gacS from Pseudomonas fluorescens was associated with a reduction in the production of both antibiotics, 2,4-diacetylphloroglucinol and mono-acetylphloroglucinol, produced by Enterobacter cloacae CAL2. With Enterobacter cloacae CAL2, plasmid-borne rpoS, but not gacS, increased the level of ACC deaminase activity, while introduction of rpoS in Enterobacter cloacae UW4 caused a decrease in ACC deaminase activity. Neither gacS nor rpoS significantly affected the level of siderophores synthesized by either bacterial strain. Overproduction of either GacA or RpoS in Enterobacter cloacae CAL2 resulted in a significant increase in the root lengths of canola seedlings when seeds were treated with the bacteria, and overproduction of RpoS caused an increase in canola shoot as well as root lengths.Key words: plant growth-promoting bacteria, canola, ethylene, ACC deaminase, GacS, RpoS, indoleacetic acid, siderophores, antibiotics.

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