Mitochondria-Nucleus Interactions: Evidence for Mitochondrial Retrograde Communication in Plant Cells

Abstract

There is increasing awareness of the intricate communication networks and signal transduction pathways that link plant organelles. It appears that in some situations altered expression of specific nuclear genes is directed by other organelles. This is referred to as retrograde regulation of nuclear gene expression and is presumably dependent upon some form of retrograde communication (signaling) from the other organelles to the nucleus. Relatively little is known about the mechanisms involved in mitochondrial retrograde regulation of nuclear gene expression in plants. Nonetheless, experimental results from yeast, mammalian and plant cells indicate that mitochondria participate in the sensing of developmental cues, as well as biotic and abiotic stresses, and that this sensing then initiates retrograde regulation of nuclear gene expression. Here we present the current state of research regarding the potential roles and mechanisms of mitochondrial retrograde regulation in higher plants.