Deoxynivalenol (DON) disrupts chloroplast function in plants. This study investigates the impact of DON on chloroplasts in diverse plant species, including Arabidopsis and cereals, drawing insights from the model green alga Chlamydomonas reinhardtii.
While Chlamydomonas exhibits a robust chloroplast unfolded protein response (cpUPR) upon chloroplast stress, involving the upregulation of nuclear genes encoding protective proteins, this response appears to differ in higher plants. Specifically, key protective cpUPR-related nuclear genes in Arabidopsis, such as VIPP1 (encoding a thylakoid membrane protein) and associated-chloroplast heat shock proteins, did not show the same level of induction observed in Chlamydomonas when exposed to DON. This suggests potential variations in stress response mechanisms, particularly those related to the chloroplast, between algae and higher plants.
Despite these differences, trichothecenes caused significant chloroplast damage, such as reduced chlorophyll content and altered thylakoid membrane structure in all species tested, as evidenced by chlorophyll fluorescence imaging. This highlights a conserved detrimental effect of these toxins on chloroplast integrity, regardless of the specific response pathways activated. This research provides insights into the complexities of plant responses to trichothecene-induced chloroplast stress and may contribute to a better understanding of these virulence factors, particularly their role in disrupting chloroplast function and inducing disease in cereal crops.