Genetic analyses of cell death in maize (Zea mays, Poaceae) leaves reveal a distinct pathway operating in the camouflage1 mutant

Controlled cell death is vital for many physiological processes in plants, such as xylem development, the hypersensitive response (HR), and senescence; however, the pathways governing cell death are incompletely understood. Studies of mutants that display a cell‐death phenotype have greatly contributed to our knowledge of how this process is regulated. The maize camouflage1 ( cf1 ) mutant displays the novel phenotype of cell‐specific death of bundle sheath (BS) cells in discrete yellow leaf tissues. To investigate the BS cell death in cf1 mutants, we characterized potential underlying factors. Hydrogen peroxide (H 2 O 2 ) is known to be involved in many cell‐death events in plants, including the HR. However, in vivo staining found no accumulation of H 2 O 2 in cf1 mutant leaves. Additionally, genetic analyses determined that functional chloroplasts are required for cf1 BS cell death. These results demonstrate that cf1 BS cell death occurs via a distinct pathway from that seen in a functionally related maize mutant or in the HR, suggesting that cell death in maize leaves can be caused by multiple mechanisms.