How Plants Decide to Grow or Defend: Key Protein Revealed

Plants can choose to either grow or defend themselves when their survival depends on it. Now, scientists have discovered how these organisms use steroid hormones to accomplish just that, revealing a bit more about the unusual mechanisms that plants employ.

"A major dilemma faced by plants is whether to invest their energy in growth or defending against pathogens," said Cyril Zipfel, one of the researchers, in a news release. "Knowing how this is controlled adds a powerful tool in our ability to breed disease resistant plants with maximum yield.

In this case, the scientists identified a key protein BZR1. This protein controls the activity of genes related to immunity and is involved in growth mediated by steroid hormones called brassinosteroids. These hormones are common to all plants. This protein is also responsible for rapidly tipping the balance in favor of growth and ignoring pathogen attack when it is a matter of life and death. For example, this is the case when a seed germinates in the soil.

"Light is essential for plant's survival the number one priority for a seedling is to reach sunlight," said Rosa Lozano-Durano, one of the researchers, in a news release. "Investing the limited resources in fighting back a pathogen could have lethal consequences."

Currently, researchers are already focusing on brassinosteroids in order to breed semi-dwarfed cereal crops. Yet this latest study has paved the way for continuing these studies. Reducing the levels of brassinosteroids or their activity could have the added benefit of making crops better able to resist disease.

The findings reveal a bit more about the mechanisms that plants use in order to survive. In addition, the latest study could help researchers breed and modify crops in order to increase yield and resist pests. This could help with food security in the future.