Plant biology | 2021
The role of alternative oxidase in plant hypersensitive response.
Abstract
The innate immune system of plants is very 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 hypersensitive response is the shift of 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 energy status of the cell. Alternative oxidase has been attributed to minimize reactive oxygen species production and can also function as an Anti-apoptotic machinery in a plant cell. In this mini review, we briefly describe alternative respiratory pathway and explain the role of alternative oxidase in important cellular processes like programmed cell death and hypersensitive response.