How Plant Growth Is Impacted By Oxygen?

Oxygen is crucial for optimal plant growth, impacting photosynthesis and respiration. It is regulated through multiple interlinked signaling pathways and can be affected by adverse conditions such as microorganisms and abiotic factors like temperature, waterlogging, and salinity. Oxygen deficiency affects plant growth, development, and distribution in terrestrial and aquatic ecosystems, as well as crop yield losses worldwide.

Plants grow more at night than during the day due to environmental changes during the diel cycle and endogenous cues like the circadian clock. High levels of micronutrients contribute to the generation of reactive oxygen species (ROS), which can cause extensive cellular damage. Plants use sunlight, carbon dioxide from the atmosphere, and water for photosynthesis to produce oxygen and carbohydrates for energy and growth. Rising levels of CO2 in the atmosphere also play a role in maintaining normal plant growth and improving their tolerance to stress.

Oxygen is essential for plant respiration and mitochondrial energy generation, as it is used in aerobic respiration, where food molecules are broken down to release energy for growth. This process releases carbon dioxide as a waste product, which is used in photosynthesis, where the sun’s energy is harnessed to make food. Oxygen is the limiting factor for quality crops, as the amount of oxygen available to root cells matters for healthy plant growth rate and crop health.

Soil oxygen deficiency reduces respiration, mineral uptake, and water movement in roots, potentially impacting plant growth. Poor oxygen supply, such as waterlogged or compacted soils with limited aeration, can lead to root damage, reduced growth, and smaller plants. Low oxygen enhancement of photosynthesis declines over time, and after 10 days, leaf area and root dry weight are less than in plants grown in normal air.

What is the role of oxygen in plant growth?

Plants need to breathe to function and absorb gases from the atmosphere. They use oxygen for aerobic respiration and carbon dioxide for photosynthesis. Plants don’t have lungs to inhale and exhale the air, but they ‘breathe’ in and out oxygen and carbon dioxide. Oxygen is used in aerobic respiration, where food molecules are broken down to release energy for growth. Plants absorb these gases through tiny breathing pores in their leaves, moving through diffusion from high concentration to low concentration. Roots also need oxygen, which they absorb from air spaces in the soil, making well-aerated soil essential for good growth.

How do plants sense oxygen?

Plants require molecular oxygen for respiratory energy production and can experience hypoxic conditions during natural events, developmental processes, and cells of compact tissues with high metabolic rates. Plant acclimation responses to hypoxia involve modulating gene expression, leading to various biochemical, physiological, and morphological changes that stave off eventual anoxia. A direct oxygen-sensing mechanism in plants has been elusive, but recent independent studies show that oxygen sensing in plants operates via posttranslational regulation of key hypoxia response transcription factors by the N-end rule pathway.

Results from these studies demonstrate that oxygen-dependent modification and targeted proteolysis of members of the ethylene response factor group VII transcription factor family regulate hypoxia-responsive gene expression in Arabidopsis thaliana.

Plants are also strongly dependent on external oxygen supply, as they lack an active oxygen distribution system. This means dense and metabolically active tissues can quickly develop hypoxic cores even when oxygen is externally available. Oxygen deficiency can occur in the external environment, such as during winter ice encasement or flooding. Under conditions of limited oxygen availability, ATP production via oxidative phosphorylation is constrained, negatively affecting cellular energy status. Acclimative responses to hypoxia include a switch to an energy-conserving mode, involving lower ATP consumption and the use of pyrophosphate as an alternative energy donor.

The biochemical and physiological reconfiguration triggered by hypoxia is also reflected in the molecular response of plants to hypoxia, including the induction of genes encoding fermentative and glycolytic enzymes, many transcription factors (TFs), and several genes of unknown function. Most plant species switch on this core set of hypoxia-responsive genes, and there is a surprisingly conserved response of different cell types of Arabidopsis thaliana to low-oxygen stress.

What happens when a plant is deficient in oxygen?

Oxygen starvation is a condition where plants experience a sudden decrease in oxygen levels, leading to a decrease in plant growth and potentially causing death. This condition can cause leaves to wilt, become distorted, and drop prematurely, causing yellowing and other symptoms. Petioles may also droop, while the entire plant may wilt or exhibit shoot dieback. Oxygen starvation can also damage or kill roots, inhibiting their function. Symptoms may appear quickly or slowly, depending on the soil, the cause, the plant’s health, age, and care received.

Oxygen starvation can increase plant susceptibility to secondary disease and insect problems. The amount of oxygen in a soil is dependent on its texture, structure, permeability, water content, and compaction.

Why do we need oxygen to grow?

Oxygen is a vital element for the majority of living organisms, facilitating essential processes such as growth, reproduction, and energy conversion. The human body obtains oxygen through the process of respiration, which enables cells to metabolize food for the production of energy. While other animals utilize disparate organs for respiration, all are ultimately reliant on respiration as a means of obtaining oxygen.

What happens if plants have too much oxygen?

The level of oxygen in plants is dependent on the crop and can cause stunted growth. When there is too much oxygen, roots have less motivation to grow larger, leading to less biomass and leaf tissue. For crops like tomatoes, peppers, and cucumbers, the whole plant would be stunted. To reach excessive oxygen levels that damage plants, growers can use liquid oxygen or ozone. Air pumps or air stones won’t be high enough to stunt plant growth. To reach higher oxygen levels of 15-16 ppm, growers must use other methods like liquid oxygen and ozone.

It’s difficult to reach high oxygen levels above 10 ppm unless an alternative method is used. Growers using a deep water raft system can increase turbulence in the pond to increase oxygen levels, but too much turbulence can sometimes cause damage to the roots.

How does oxygen affect growth?

The study investigates the growth of human diploid fibroblasts (WI-38 and IMR90) in response to initial seeding density and oxygen tension. The cells were subcultured in Dulbecco’s modified Eagle’s medium with 10 fetal bovine serum at various levels. The flasks were equilibrated before and after seeding with gas mixtures containing the desired oxygen tension. The partial pressure of oxygen (PO2) in the media was determined at harvest.

The results showed that cell growth varied inversely with oxygen tension and seeding density. Growth was maximal at PO2 9 and 16 mm Hg, and growth was progressively inhibited as the oxygen tension increased. The population doubling increase at 14 days was 8. 6 for PO2 9 and 16 mm Hg, 5. 8 for PO2 42 mm Hg, 3. 8 for PO2 78 mm Hg, 3. 8 for PO2 104 mm Hg, and 3 for PO2 138 mm Hg.

As seeding density increased, the differences in growth at PO2 less than 140 mm Hg were progressively minimized, resulting in little difference in the rate of exponential growth or final saturation density of cells cultivated between PO2 9 and 96 mm Hg. Growth was progressively inhibited when PO2 was increased greater than 140 mm Hg.

The study found that oxygen regulates the growth of human cells under pressures of oxygen physiologic to humans, and that oxygen toxicity contributes to the seeding density dependence of cellular growth commonly seen in cell culture.

What are the effects of low oxygen on plants?

Low oxygen environments can decrease the utilization of assimilates, potentially leading to inhibition of photosynthesis. Access to content on Oxford Academic is typically provided through institutional subscriptions and purchases. Members of an institution can access content through IP-based access, which is provided across an institutional network to a range of IP addresses. This authentication occurs automatically and cannot be accessed.

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What is the importance of the oxygen that plants produce?

Oxygen is essential for all aerobic organisms, including plants and photosynthetic bacteria and algae, to survive and produce energy from sugars. Plants, along with photosynthetic bacteria and algae, support the biodiversity of life across ecosystems, including humans. The emergence of photosynthetic organisms around 3 billion years ago increased oxygen levels, supporting the evolution of aerobic life. Plants are major consumers of greenhouse gases CO2 and producers of O2, maintaining the delicate ratio of gases in our atmosphere.

As global warming increases, the importance of plant photosynthesis is set to increase. Plants actively reduce global warming by taking in CO2, acting as a carbon sink. With increasing CO2 emissions from human activity, increasing the photosynthetic capacity of plants and algae could potentially slow Earth’s rapid warming.

What happens if a plant lacks oxygen?

It is a fundamental biological principle that plants, including their roots, require oxygen for the process of cellular respiration. In the event that the soil is saturated with water and lacks air pockets around the roots, the plant will experience starvation and ultimately perish, as these areas require oxygen for respiration.

Why is air important for plant growth?

Plants require air for photosynthesis and respiration, which are essential for converting food into energy. The relationship between air and indoor plants is crucial for their health. Stagnant air, which is often invisible and readily available to plants above ground, can disrupt the availability of fresh air. Stagnant air may be low in vital gases like oxygen and high in other harmful gases. When plants are placed indoors, fresh air is depleted over time, leading to the build-up of toxic gases.

For example, a banana wrapped in a plastic bag can experience rapid depletion of fresh air, causing oxygen levels to drop and ethylene to be released, leading to faster ripening. This can also happen to foliage plants if not exposed to fresh air, resulting in damaged or dead foliage.

Does oxygen affect plant growth?

Oxygen availability is crucial for plant growth and development, as it is required in various metabolic processes such as carbohydrate metabolism, nitrate reduction, symbiotic nitrogen fixation, protein renewal, and nutrient absorption by roots. This oxygen is essential for root growth and shoot development, impacting the overall plant’s development. Plant respiration, an oxidative process controlled by metabolic pathways, helps avoid low energy availability, even in hypoxia. However, knowledge of its regulation is limited.

Frequent oxygen deficiencies in the rhizosphere can result from high rates of radical respiration due to high temperatures, insufficient aeration capacity, or inadequate irrigation management. This has led to various oxygenation techniques, such as aeroponia, oxygenation, and oxyfertigation, to minimize hypoxia risks and increase yield and quality of agricultural crops.

This work aims to review the evidence on the effects and importance of oxygen availability in the rhizosphere for plant growth and development, as well as the benefits of oxyfertigation in minimizing hypoxia risks and increasing yield and quality of agricultural crops.