Plant Development - What Are The Effects Of High Temperatures On Plant Development?
It is anticipated that global warming will have a negative overall effect on plant growth because high temperatures have detrimental effects on plant development.
A catastrophic loss in crop productivity and widespread famine could result from the rising threat of climatological extremes, such as extremely high temperatures.
The effects of climate change vary depending on the region and the crops that are most likely to see dramatic yield reductions due to expected extreme temperature swings and general global warming.
High temperature stress is something that plants experience, and it has a variety of effects on their physiology, biochemistry, and gene regulatory pathways.
However, there are techniques that can be used to create crop varieties that are more heat stress resistant.
COPYRIGHT_WI: Published on https://washingtonindependent.com/w/plant-development/ by Jaya Mckeown on 2022-08-04T13:47:25.261Z
The growth of plants is impacted in a variety of ways by high temperatures. The effects of heat on photosynthesis, in which plants use carbon dioxide to produce oxygen, and respiration, the converse process, in which plants produce carbon dioxide from oxygen, are the most obvious.
The two processes, however, become unbalanced when the temperatures reach limits that are uncomfortably high. These limits vary depending on the plant. When temperatures exceed approximately 96 degrees Fahrenheit (36 degrees Celsius), for instance, it can be harmful to tomatoes.
The impact that temperature has on plants can vary greatly depending on a number of factors, including elevation, exposure to sunlight, moisture drainage, the difference in temperature between the day and the night, and proximity to the thermal heat mass that is provided by the rock structure that is all around them.
How do hot temperatures affect plants?
Abiotic stresses are frequently interconnected; whether acting alone or in concert, they alter the morphology, physiology, biochemistry, and molecular structure of plants, which has a negative impact on the plants' productivity and, ultimately, their yield.
This has a negative impact on the environment as a whole as well.
The primary abiotic stresses that cause severe cellular damage in plant species, including crop plants, are high temperatures, extended periods of drought, low temperatures, and high salinity.
Variations in temperature are a natural and necessary component of the growth and reproduction of plants.
However, extreme variations during hot summers can cause damage to the intermolecular interactions that are necessary for healthy growth.
As a result, plant development and fruit set will be hampered by these conditions.
Heat waves have a significant negative impact on crop yields around the world, which in turn has a significant negative impact on agricultural production and poses serious risks to future food security on a global scale.
It is anticipated that climatological extremes, such as extremely high temperatures, which will generally have a negative impact on plant growth and development, will ultimately lead to widespread famine and a catastrophic loss in crop productivity.
In the future, the rise in the human population will bring about new challenges for agricultural production, and as a direct result, for the safety of food supplies all over the world.
Currently, 15% of the world's wheat production comes from the Indian lowlands, but climate change will make this region a short-season, heat-stressed production environment.
Plants have many defenses against high temperatures. These are long-term phenological and morphological evolutionary adaptations, such as leaf orientation or membrane lipid composition, or short-term stress avoidance and acclimation mechanisms.
Stress proteins, osmoprotectants, free-radical scavengers, ion transporters, signaling cascade and transcriptional control factors, and others are crucial for reducing the effects of stress.
Plant Health in a Changing Climate
Several plant physiological parameters and mechanisms contribute to heat tolerance in the field, such as modifying photosynthesis and increasing protective protein transcripts.
A heat-tolerant variety has higher photosynthetic rates, increased membrane thermostability, and avoids heat.
In all plant species, leaf gas exchange under heat stress is linked to heat tolerance.
Since carbon fixation by Rubisco is the main site of thermal injury, the decline in active Rubisco can be largely responsible for the negative temperature response of net photosynthesis.
Reactive oxygen species are harmful because of the decrease in carbon fixation and oxygen evolution.
The mechanism that would typically repair the damaged photosystem is therefore prevented.
The development of high-temperature crops may benefit from manipulating leaf photosynthesis and photosynthate partitioning.
Tissue senescence, which is characterized by membrane damage, increased fluidity of membrane lipids, lipid peroxidation, and protein degradation, can be brought on by heat stress.
This is why membrane lipid saturation is thought to play a significant role in high temperature tolerance.
In membrane lipids, a higher proportion of saturated fatty acids leads to a higher melting temperature and prevents heat-induced membrane fluidity.
As temperatures rise, plants up their intake of saturated and monounsaturated fatty acids to maintain membrane fluidity.
The stability of the membrane and heat tolerance appear to depend on increasing fatty acid saturation.
Secondary metabolite synthesis is increased in response to heat stress, preventing oxidative damage.
The accumulation of phenolics is caused by thermal stress, which activates their biosynthesis and inhibits their oxidation, according to several studies on tomatoes and watermelons.
It's possible that this protects plants from thermal stress by allowing them to adapt.
Plants can adjust to a wide range of temperatures by altering their transcriptome, proteome, and metabolome and even by activating cell death mechanisms, which can result in organ abortion or plant death as a whole.
Repairing heat-sensitive parts and preventing further heat injury lead to the capacity to withstand or adapt to higher than ideal temperatures; metabolic homeostasis is also preserved under stress.
The enormous production of HSPs is the key aspect of thermotolerance.
The development and maintenance of thermotolerance, however, also depend on a variety of biochemical and metabolic traits, including antioxidant activity, membrane lipid unsaturation, gene expression and translation, protein stability, and accumulation of compatible solutes.
Nevertheless, as some genotypes are more tolerant than others, the responses of plants to high temperatures during development clearly depend on genotypic factors.
Given that knockout versions of HSP101, HSA32, HSFA1, and HSFA3 had little effect on heat tolerance, several studies revealed that while some HSFs are essential for thermotolerance, others (HSP101, HSFA1, HSFA3) play a less essential role.
These findings also suggest that a sophisticated regulatory system offers various levels of heat stress defense.
According to a recent study, despite the absence of the HSFA1 transcription factor, Arabidopsis mutants can still develop acquired thermotolerance after acclimation.
This is probably because a small number of genes regulated by other transcription factors, like bZIP28, are induced.
However, HSPs play a crucial role in thermotolerance reactions because they function as molecular chaperones to stop target proteins from becoming denaturized or aggregating and to promote protein refolding.
Normal increases in transcripts involved in the biosynthesis of protective components and a lesser impact on vital processes like photosynthesis are characteristics of heat tolerance.
A heat-tolerant variety will typically exhibit higher photosynthetic rates as shown by stay-green leaves, increased membrane-thermostability, and successful fruit setting in high temperature conditions.
Photosynthesis and reproductive development are the physiological processes that are most sensitive to stress.
Due to the fact that tolerance to high temperatures is a multigenic trait, there are numerous opportunities for plant improvement.
Due to interactions with other environmental factors, heat tolerance screening in the field is difficult, but there are many different screenable traits that enable successful selection in the field.
In controlled environments, tolerable genotypes can also be chosen.
Controlled environments, however, are more expensive and do not allow for natural selection for additional elements that could affect the mechanisms for coping with heat stress in the field.
No matter the screening technique, one of the main goals for plant breeders is to create a useful set of thermotolerance markers that can be applied to further develop heat tolerance in various crop species.
Analysis of plant phenology in response to heat stress frequently provides a better understanding of the plant response and facilitates further molecular characterization of the tolerance traits because plants adapt to temperature stress by developing more suitable morphological, physiological, and biochemical characteristics.
By establishing functional connections between genetics and the associated phenotype, emerging phenomic methodologies are used to find the genes responsible for desired traits.
The performance of plants in controlled settings or in the field is also characterized using such tools.
The temperature and duration of heat stress treatments that affect plant growth and development vary by tissue and growth stage, so choosing an appropriate phenotype is crucial.
The function of a heat stress response gene may contribute to thermotolerance differently across tissues and growth stages.
A systematic phenotyping approach that includes a range of heat stress conditions may increase the chance of identifying heat stress response gene functions.
Elliot Meyerowitz (Caltech , HHMI) 1: Why we need to understand plant development
The normal cellular homeostasis is disrupted when a plant is subjected to heat stress, which can result in the plant's growth being stunted or even its death.
The production of reactive oxygen species (ROS) and their accumulation in the plant body against high temperature-induced signals was the mechanism that led to these impairments.
The disruption of food availability and access, as well as the degradation of food quality, can be caused by climate change.
Reduced agricultural productivity may be the result of a number of factors, including, but not limited to, projected increases in temperature, changes in the patterns of precipitation, changes in the frequency and intensity of extreme weather events, and decreased availability of water.
The uptake of salt by plants is reduced when they are subjected to salt stress, and the plants also adjust their osmotic pressure by producing compatible organic solutes.
Compatible solutes are low-molecular-weight compounds that are highly soluble and, in most cases, non-toxic even when present in high concentrations within cells.
Agriculture is particularly susceptible to the effects of climate change. In the long run, temperatures that are higher will result in lower yields of desirable crops while simultaneously fostering the growth of weeds and pests.
Alterations in the patterns of precipitation make it more likely that crops will fail in the short run and that production will drop in the long run.
With each growth stage, the effect of abiotic stresses on the development of plants becomes more complex.
Because incomplete tolerance mechanisms prevent accurate phenotyping of stress responses, conventional and molecular plant breeding efforts are constrained.
Facilities for conducting public research phenotyping are difficult to come by in developing countries.
Differences in their primary concerns and research strategies cause molecular biologists, plant physiologists, and breeders to work independently.
Such integration will enable the identification of tolerance genes and elucidate the functional relationships between genotype and observed phenotypes, providing a system-wide phenome for genome analysis and accurate trait mapping and introgression of superior alleles for complex characters like abiotic stress tolerance.
In order for plant breeders to be able to design new ideotypes in silico, construct new genotypes in plants, and ultimately implement these across a wide range of environmental conditions and locations in light of the anticipated warming of the planet, it is essential for them to understand the molecular basis of the relevant agronomic traits.