Polyphenol oxidase and red clover

Leaf polyphenol oxidase (PPO) is an important agronomic trait in red clover, improving meat production while reducing the industry’s environmental impact. While PPO is not needed for normal plant growth, it does protect plants against pathogens.
Red clover has a large PPO gene family; one allelic gene governs most leaf and nodule PPO activity in healthy tissues. Plant cultivar, genotype and leaf age along with abiotic and biotic stresses all alter leaf PPO activity. Understanding what controls PPO gene expression and enzyme activity will clarify its role in plant development and direct breeding for cultivars well-suited to current needs.