Exogenous treatment with the plant hormone, ABA or auxin, induces enhanced susceptibility against biotrophic pathogens. Design an experiment that can reveal whether these hormones use the same signalling pathway or independent pathways to induce susceptibility.
To design an experiment to determine if the plant hormones ABA (abscisic acid) and auxin use the same signaling pathway or independent pathways to induce susceptibility against biotrophic pathogens, you could follow the steps below:
1. Plant selection: Choose a suitable plant species that is known to respond to both ABA and auxin treatments and have well-studied interactions with biotrophic pathogens.
2. Pathogen selection: Choose a biotrophic pathogen that has been extensively studied and is known to infect the selected plant species.
3. Treatment groups: Divide the plants into several treatment groups: control (no hormone treatment), ABA treatment, auxin treatment, and a combined ABA+auxin treatment group. Make sure to have a sufficient number of replicates in each group for statistical analysis.
4. Hormone treatment: Apply ABA, auxin, or both hormones to the respective treatment groups following the appropriate concentrations and treatment duration based on previous studies or pilot experiments. Ensure that control plants receive a suitable solvent as a mock treatment.
5. Infection: After the hormone treatments have been administered, inoculate all the plants with the biotrophic pathogen, following established infection protocols.
6. Disease assessment: Monitor and record disease progression for each plant over a defined time period. Measure relevant disease parameters such as lesion size, pathogen growth, symptoms, or other indicators of susceptibility.
7. Statistical analysis: Quantitatively analyze the disease data obtained from the different treatment groups using appropriate statistical tests (e.g., ANOVA) to compare the effects of the treatments. This analysis will help determine whether the treatments have significant effects on pathogen susceptibility.
8. Comparative analysis: Compare the disease data among the different treatment groups. If the ABA and auxin treatments induce a similar level of susceptibility, it would suggest that they likely share a common signaling pathway. On the other hand, if the treatments result in different levels of susceptibility, it would suggest independent pathways for ABA and auxin in inducing susceptibility.
9. Additional controls: To ensure the experiment's validity, include additional control groups such as infected plants with no hormone treatment or infected plants treated only with the solvent. These controls will help assess the normal susceptibility of the plant to the pathogen and ensure that any observed changes are specifically due to the hormone treatments.
10. Repeat and validate: Perform multiple independent repetitions of the experiment to validate the results and confirm the consistency of the findings.
By following these steps, you can design an experiment that investigates whether ABA and auxin use the same signaling pathway or independent pathways to induce susceptibility against biotrophic pathogens in plants.