Can the presence of a fungal volatile organic compound improve plant resilience to abiotic stress? : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University

Climate change is a matter of increasing concern, as the severity, duration, and area affected by drought have steadily risen since the 1970s. These changes have severely affected the agricultural industry, as drought stress is a major contributor to crop loss. Therefore, it is crucial to develop new strategies to address this problem. Seed coating shows the potential to mitigate the challenges faced by the agricultural industry, as it provides physical and physiological properties to seeds, helping alleviate both biotic and abiotic stress. This research aims to evaluate the protective effect of the fungal volatile (FVOC) organic compound when applied via polymer seed coating. The FVOC seed coating treatment's effects were assessed regarding plant emergence, resilience to drought stress, and transgenerational stress adaptations. By conducting a comprehensive transcriptomic analysis, it was possible to identify the transcriptional changes induced by the presence of the FVOC molecule. The application of the FVOC led to significant changes in gene expression in plants under drought-stress conditions, enabling them to cope more effectively with stress. Moreover, when plants grown from FVOC-treated seeds were exposed to a second round of drought stress, they exhibited a more specific and refined response to this stress. Moreover, when the second-generation plants derived from FVOC-treated seeds were exposed to drought, they exhibited improved resilience to environmental stress. This observation strongly suggests the occurrence of transgenerational changes. The drought stress initially triggered these changes in the first-generation plants and was further enhanced by the presence of the FVOC molecule. Subsequently, these changes were transmitted to the second generation, resulting in enhanced resilience plants.