A fast and reliable method to measure the activity
of photosynthetic herbicides in intact plants

The Problem

Why do we need such method?

Modern agriculture relies essentially on herbicides for managing weeds and the use of herbicides is not foreseen to diminish in near future. Understanding the mechanism of action of a given group of herbicides is critical and this includes not just identifying its target site in an isolated model system but knowing all aspects of interaction with the whole plant. Spectroscopic methods such as delayed fluorescence (DF) are one possible solution for studying the interaction between herbicides and plants in vivo.

We could take advantage of the rapid acquisition and analysis of luminescence data which is possible with the present technology, and develop a DF-based method for measuring the herbicide efficiency in different plants. This could serve not only in basic photosynthesis research but also in applied science as an easy and affordable screening method for testing new herbicides or herbicide-resistant biotypes.

What should we do to have such method?

1. Find how DF responds to the herbicide action.

  • Among all DF data that can be measured, find the properties of DF that are directly related to the action of herbicides.
  • Select such DF properties that can be quantified with minimal error.
  • Discover the relationship between the DF properties and herbicide concentration (the dose-response relationship).

2. Find an appropriate procedure for treating the sample plants with herbicides.

  • In order to express their action, photosynthetic herbicides must be delivered to the chloroplasts inside the plant's cells. However, native plants are not necessarily eager to let poisonous agents in. There are many barriers that could stop the herbicide molecules from penetrating, such as the leaf cuticle and the epidermis.
  • The treatment procedure must guarantee that the exact dose of herbicides will enter into the chloroplast, so that the method will be statistically reliable.
  • The treatment procedure itself must not be damaging to the plant.

3. Set the protocol for treatment, registration and analysis of the results.

Before proceeding with these steps, you might want to read about the photosynthetic apparatus, the mechanisms of delayed fluorescence emission, and the photosynthetic herbicides. Introductory material on these topics can be found in the Theory section.

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