Figure 9.

The schematic diagram shows the orf116b module-based mechanism inducing pollen abortion in the cotton line J4A. As per the proposed model, the rearrangement of the J4A mt genome produces a new gene, orf116b. Orf116b protein is toxic and adversely affects mt function, leading to mt dysfunction with excessive ROS accumulation and reduced ATP production. Orf116b triggers abnormal proliferation and delayed PCD of tapetal cells in anthers, leading to pollen sterility. Orf116b also appears to interact with an anther-specific protein, LAT52, in the mt and contributes to CMS in J4A; however, this mechanism needs further investigation.