Voltage-dependent anion channels: their roles in plant defense and cell death.

The voltage-dependent anion channels (VDACs), mitochondrial outer membrane components, are present in organisms from fungi to animals and plants. They are thought to function in the regulation of metabolite transport between mitochondria and the cytoplasm. Sufficient knowledge on plant VDACs has been accumulated, so that we can here summarize the current information. Then, the involvement of mitochondria in plant defense and cell death is overviewed. While, in mammals, it is suggested that VDAC, also known as a component of the permeability transition pore (PTP) complex formed in the junction site of mitochondrial outer and inner membrane, is a key player in mitochondria-mediated cell death, little is known about the role of plant VDACs in this process. We have shown that plant VDACs are involved in mitochondria-mediated cell death and in defense against a non-host pathogen. In light of the current findings, we discuss the role of the PTP complex and VDAC as its component in plant pathogen defense and cell death.