Prohibitin is involved in mitochondrial biogenesis in plants.

Area of Science:

• Plant Biology
• Mitochondrial Biology
• Molecular Genetics

Background:

• Prohibitins (PHB1 and PHB2) are vital for mitochondrial function and cellular processes in mammals and yeast.
• Their role in plant physiology, particularly in relation to mitochondria, remains largely unexplored.

Purpose of the Study:

• To investigate the function of prohibitin subunits (NbPHB1 and NbPHB2) in Nicotiana benthamiana.
• To elucidate the role of prohibitins in plant mitochondrial biogenesis, stress response, and senescence.

Main Methods:

• Virus-induced gene silencing (VIGS) was employed to suppress NbPHB1 and NbPHB2 expression in N. benthamiana.
• Mitochondrial morphology, number, mass, and physiological functions were assessed.
• Reactive oxygen species (ROS) production and plant responses to oxidative stress were analyzed.

Main Results:

• Suppression of NbPHB1 and NbPHB2 targeted these proteins to mitochondria and affected their gene expression during senescence.
• VIGS of NbPHB2 induced severe growth inhibition and cell death symptoms; NbPHB1 suppression caused milder effects.
• Depletion of prohibitins led to reduced mitochondrial number/mass, morphological/physiological abnormalities, and increased ROS production (10-20 fold).
• Prohibitin disruption accelerated leaf senescence and increased susceptibility to oxidative stress agents (H2O2, paraquat, antimycin A, salicylic acid).

Conclusions:

• Prohibitins are crucial for maintaining mitochondrial integrity and function in plant cells.
• These proteins play a significant role in regulating plant stress tolerance and preventing premature senescence.
• The findings highlight prohibitins as key regulators of mitochondrial biogenesis and cellular defense mechanisms in plants.