Exploring the effect of pulsed electric field on the growth and stress tolerance of oat seedlings

Abstract

Plants are exposed to harsh environments due to climate changes, which lead to reduction in productivity and yield of the crops. In order to promote stress tolerance in plants, several chemical, microbial and pulsed power methods are applied in agriculture. Pulsed Electric Field (PEF) is an alternative non-chemical and environmentally friendly technology that can be applied to promote the growth
of crops. This study is a systematic study investigating the effect of 15 different PEF protocols on the development of germinated oat seeds. To the best of our knowledge, this is the first systematic study on the effect of PEF on oat seeds. One PEF protocol was selected among the 15 PEF protocols which showed a significant promotion in oat seed germination and seedling development (p<0.05). The PEF parameters for the selected PEF protocol were E = 2.25 kV/cm, t = 10 µs and n = 99
pulses. The selected PEF protocol was applied to oat seeds at three different stages of germination to investigate the effect of this PEF protocol on oat seeds at different germination stages. Seeds at stage-1 of germination had no roots or shoots, seeds at stage-2 of germination had only one root and seeds at stage-3 of germination had both roots and shoots when treated with PEF. Three different growth experiments were performed: growth without stress, growth with salinity stress and growth with drought stress. The results from the growth experiments without stress showed a significant decrease in root growth for stage-1, no significant difference for stage-2, and a significant increase in root and shoot growth for stage-3 of germination (p<0.05). As for germinated oat seeds exposed to drought stress, a significant decrease in growth of seeds at stage-1 was observed, and no significant
differences appeared at stage-2 and stage-3 of germination (p<0.05). And for growth in salinity stress, the results showed no significant differences at stage-1, a significant increase in shoot weight at stage-2 and a significant promotion of shoot growth for stage-3 (p<0.05). The results from this thesis work shows that the PEF protocol applied and the germination stage of the seeds have to be investigated to find the right PEF parameters and germination stage.

Popular Abstract

Applying a non-thermal, non-chemical, and environmental friendly technology to promote growth and stress tolerance in germinated oat seeds.

Oats are nutritious crops that can be added to gluten-free diets and provide
umerous health benefits. However, environmental stresses like drought and salinity are affecting grain productivity, which includes oat production. Especially drought stress, as oats require large amounts of water during growth period. In this thesis work, Pulsed Electric Field (PEF) was applied to oat seeds to promote the growth and stress tolerance of the oat plant. PEF is a non-thermal technology that was used to apply short, high voltage electrical pulses to oat seeds at different stages of germination that were placed between two electrodes. The effect of PEF on the oat seeds can either be reversible or irreversible. If the cells are destroyed, it is an irreversible permeabilization. And if the cells recover after PEF treatment, it is a reversible permeabilization. In this thesis work, the desired outcome was the reversible permeabilization. Starting with 15 different PEF protocols and narrowing it down to the “best” PEF protocol was possible as the selected PEF protocol did significantly promote the growth of germinated oat seeds. The selected PEF protocol was applied to oat seeds at three different stages of germination for growth experiments and additionally to expose the PEF treated germinated seeds to salinity and drought stress. Different activities on molecular, biochemical and physiological levels occur at different germination and growth stages. For example, during the germination phase (phase-1 of growth), the dry oat seed tries to absorb as much water as possible so that the roots and shoots can grow and break the seed coat. Therefore, the main research question was: does PEF treatment at different levels of oat seed germination have different impacts on the development of the oat seeds? The results from this thesis work showed that treating oat seeds at different stages of germination with the same PEF protocol had different outcomes and it depended on the germination stage. For growth experiments in water and nutrients, it was observed that PEF decreased the growth of oat seeds at early stages of germination, whereas treating seeds at later stages of development did promote the growth. As for growth experiments with stress, there was also a difference in the results, which depended on the growth stage of the seeds when treated with PEF. Therefore, PEF is a promising non chemical technology to promote oat growth and resistance towards stresses; however, PEF parameters adjustment and germination stage are two main factors affecting the effect of PEF.

• author: Al-Khafaji, Alia
• supervisor: Federico Gómez Galindo
• organization: Food Technology and Nutrition (M.Sc.)
• course: KLTM01 20231
• year: 2023
• type: H2 - Master's Degree (Two Years)
• subject: Agriculture and Food Sciences
• keywords: Pulsed electric field, Oats, Germination, Agriculture, Salinity, Drought, Abiotic stresses, Electrotechnology, Food engineering
• language: English
• id: 9134450
• date added to LUP: 2023-08-29 14:53:04
• date last changed: 2023-08-29 14:53:04