Cellular Trojans Help Against Salt Stress

What was the question behind this work? Using a wooden horse, the Greek succeeded to invade Troy and to conquer the city. Plant cells with their rigid cell wall are quite comparable to the besieged Troy. To get control over them, usually genetic engineering is employed. Hereby, foreign DNA encoding the feature of interest, is introduced into the genome. Is there no other way to manipulate cells, without the need to use the detour via the DNA? This is excactly, what our work is about:

How did we approach this question? In a cooperation between the team of Ute Schepers (Institute for Toxicology and Genetics) and Peter Nick (Botanical Institute) we developed over several years “Trojan Horses” that can invade the mitochondria of plant cells, where respiration generates energy. Oxygen is a risky stuff for a cell, because it easily gives rise to dangerous reactive oxygen species. This happens prominently under stress and is, by the way, one of the reasons, why in humans stress can also culminate in bodily damage. Our Trojan Horse does not smuggle in blood-thirsty Greek warriors, but a variant of coenzyme Q10 that can efficiently quelle reactive oxygen species.

What did we achieve? We show in this work not only that cells pretreated with these Trojan Horses, are more resilient against salt stress, but we also clarified, how the Trojan Horse reaches the interior of the mitochondria. Against the expectation, it does not penetrate through the cell membrane, but is taken up by vesicles that pass on their cargo to the Endoplasmic Reticulum. Only here, the Trojan Horse sneaks through the membrane and reaches the adjacent mitochondria. This is relevant, because plant cells respond to impaired integrity of the cell membrane by programmed cell death, a kind of suicide supposed to ward off invading pathogens. Our mitochondrial Trojan Horse elegantly circumvents this response and can therefore be used for chemical engineering of plant cells.

Publication

148. Asfaw KG, Liu Q, Maisch J, Münch S, Wehl I, Bräse S, Bogeski I, Schepers U, Nick P (2019) A Peptoid Delivers CoQ-derivative to Plant Mitochondria via Endocytosis. Nature Sci Rep 9, 9839 - pdf