It is a common misconception that the most common effect of drought on plants is wilting…but in reality, this is not the case. Wilted plants are in fact close to death and visible wilting is one of the final signs for drought stress before plant death!!
How do plants react to drought stress?
Plants and humans have very similar reactions to dehydration. They alter their metabolism to conserve moisture. In plants, the stomata are closed tightly to prevent water loss during transpiration and in humans the excretion of water is reduced.
As water begins to become scarce, the plant, or body, begins to implement further emergency procedures to conserve fluids. The cells are now suffering from internal stresses that are referred to as abiotic stresses.
Abiotic stress: Stress that is external to the plant and is non pathogenic and non biological in origin is called non-living stress or abiotic stress
Due to the heat generated by the cell’s own metabolism and the lack of transpiration, temperatures in the cells begin to rise, as can be seen in the time lapse video. At this stage of drought, the plant is not visibly wilting but is already suffering large internal metabolic stresses that, for example, reduce growth rate.
What are the effects of drought stress on plants?
These effects include:
reduced ability of the cell to perform normal functions and growth
the disruption of amino acid or protein production
the destruction of chemicals that are critical to normal cell function, but are sensitive to heat
the concentration of electrolytes or salts (osmolytes) in the cell, which can damage the mitochondria, the energy factory of the cell
As drought continues, the cells lose water because:
They are permeable and water escapes through the cell wall
Also, water from the cell is used to preserve critical functions.
As a result, the cells become soft or lose their “turgor” and only at this late stage does wilting become visible.
Even if water is provided at this stage, the cell may rehydrate and regain “turgor” but the cells functions may be permanently damaged and, as a consequence, will never again be able to achieve 100% function. In plants this results in reduced yield and quality of harvest.
Infrared timelapse visualization of the “invisible” abiotic stresses caused by drought
Tradecorp, in collaboration with Landlab, a leading Italian agricultural research centre, has created this new infrared timelapse video to demonstrate that these invisible drought effects, such as increased cell temperature or reduced growth rate do indeed occur, even before wilting is visible.
To visualize these effects, we recorded three sets of plants:
The infrared camera clearly demonstrates that before wilting occurs plants were suffering from abiotic stresses.
Leaf temperature of the untreated drought affected plant was the highest
Growth rate of the untreated drought affected plant was lower than both the plants protected with Primactive and the plants not suffering from drought stress
Wilting occurred first in the untreated drought affected plant, and was delayed in the ones protected with Primactive,
The Primactive effect can delay or even eliminate negative abiotic stresses that crops are exposed to during the normal crop cycle – in this example, drought stress. Leaf surface temperature was reduced compared to untreated plants, the onset of wilting was also delayed.
As a result, plants suffered less disruption and damage to their metabolic functions and the growth rate of the Primactive plants was much higher than untreated plants. Reduction of the negative effects of drought helps to protect yield and quality and thus profitability – all thanks to Primactive.
Tradecorp’s collaboration with Landlab and other research centres
Tradecorp and Landlab have a long history of collaboration and research. This infrared time-lapse video is but one example of the successful research projects that Tradecorp R&D and Landlab have been collaborating on. Tradecorp have used the expertise gained with Landab and other similar research type entities to develop a deep and internationally recognized understanding of Biostimulants and their optimum use in agriculture.
