fatima.naim@curtin.edu.au

Pathogen attacks elicit dynamic and widespread molecular responses in plants. While our understanding of plant responses has advanced considerably, given the complexity of the wheat genome, there is much to characterise to understand the biotic stress-driven phenotypes and their impact on plant physiology. By assessing the progression of yellow spot disease in wheat, we have shown that calcium is uniquely manipulated in susceptible wheat, and the asymptomatic regions surrounding the lesions are desensitised to follow-up infection.

A follow-up comparison of calcium re-distribution in four wheat genotypes infected with yellow spot disease found that the re-distribution of calcium depends on how the disease develops based on the environment and pathogen load. It is independent of the major wheat susceptibility gene (Tsn1), which suggests that the pathogen manipulates other interactions and results in similar disease outcomes. To further characterise this phenotype, the team investigated the potential of other interactions that the pathogen can manipulate or deploy that result in the disease phenotypes we see.

For this, a large wheat experiment was established in the glasshouse with wheat genotypes that are rated resistant to very susceptible to yellow spot. The molecular analysis comprising both short- and long-read RNA sequencing was combined with high-resolution phenotyping to associate the mineral nutrient redistribution and fungal growth to construct pathways leading to disease resistance and susceptibility.

I will present our recent findings using this layered approach and its potential in identifying novel traits.