The role of alternative oxidase in plant hypersensitive response

The innate immune system of plants is crucial in defining the fate of a plant cell during plant-pathogen interactions. This response is often accompanied by a hypersensitive reaction leading to the death of a plant cell and restricted pathogen growth. Plant mitochondria, in this case, play a key role by maintaining a balance between cell respiration and reactive oxygen species formation. One of the key features of the hypersensitive response is the shift of the normal plant respiratory pathway to a special 'alternative' pathway. Plants contain an enzyme, alternative oxidase, for maintaining metabolic homeostasis of the cell. This energy dissipating respiration provides a branch in normal respiration by using ubiquinone to form water and heat, thus maintaining the energy status of the cell. Alternative oxidase is thought to minimize production of reactive oxygen species and can also function in 'anti-apoptotic' machinery in plant cells. In this mini review, we briefly describe the alternative respiratory pathway and explain the role of alternative oxidase in important cellular processes, such as programmed cell death and the hypersensitive response.

Automated summary

The innate immune system of plants plays a crucial role in plant-cell fate during interactions with pathogens, often leading to a hypersensitive reaction related to cell death and restricted pathogen growth. Plant mitochondria are essential for maintaining a balance between cell respiration and reactive oxygen species formation, with alternative oxidase playing a key role in metabolic homeostasis and minimizing production of reactive oxygen species. This alternative respiratory pathway and enzyme function in important cellular processes, such as programmed cell death and hypersensitive response.