Plant stress takes shape in different forms. There are biotic sources of stress such as munching herbivores, viruses, fungal diseases, and bacteria. There are also abiotic sources of stress such as unfavorable temperature, deficiency or excess of water, soil salinity, and other non-living factors. Stress inhibits plant metabolism, which translates to reduced yields and quality. Understanding how plants tolerate and resist stress is important so farmers can get a better yield from their crops.
Research has shown that both biotic and abiotic stresses trigger a series of reactions in plants to help them protect themselves against those stresses. According to a study co-authored by Dr. Ravi Pottathil, biotic and abiotic stresses “activate several transcription factors and effector proteins,” which then induce the production of metabolites that help improve and protect the plant.
Dr. Pottathil spoke in a seminar organized by fertilizer trader SaraVentures on July 15, 2022 to talk about this defense mechanism which has been called priming. Scientists like Dr. Pottathil have been studying this behavior not only to understand how plants cope with stress but also to take advantage of this process. Dr. Pottathil is particularly interested in “defense priming” which uses priming to take advantage of the benefits that plants get from stress without exposing them to the source of stress in the first place.
Dr. Pottathil said that defense priming, in a way, is similar to tricking a plant into thinking that it is stressed when, in reality, it is not. Priming works through chemicals known as elicitors. Explaining the process in layman’s terms, Dr. Pottathil said in the seminar, “When an insect, fungus, or bacteria attaches to the leaves, plants cannot see them but they can smell what chemicals they secrete. These are called elicitors. Plants can smell them so correctly… that they can now recollect a few million years ago when this particular smell hurt the plant… This elicitor activates the innate immunity of plants. Once it is activated, plants can now be resistant to virus, bacteria, and fungus.”
According to his paper, defense priming can make use of agents such as live organisms like microorganisms or arthropods; chemicals such as vitamins or plant hormones; or components thereof. Once primed, a plant can defend itself more readily and effectively. For Dr. Pottathil’s study, he investigated the use of a chemically-defined elicitor on okra (Abelmoschus esculentus). The findings of his study showed that treating okra plants with the elicitor solution displayed high potential in priming the plants’ defense mechanisms.
Farmers have been used to mitigating pests through chemical pesticides, but such practices are unsustainable not only for the soil but also for the entire planet. Understanding how priming works could lead to the invention of products that can more sustainably protect and nourish plants.
The information provided here was taken from a seminar entitled “Priming: Crop Solution for Climate Uncertainty” organized by SaraVentures and Zero Gravity Solutions on July 15, 2022. Part of the event was the launching of BAM-FX in the Philippines. It is a plant mineral solution composed of zinc and copper that uses the mechanisms of priming to improve plant growth.