Natural plant defense genes provide clues to safener protection in grain sorghum

UNIVERSITY OF ILLINOIS COLLEGE OF AGRICULTURAL, CONSUMER AND ENVIRONMENTAL SCIENCES

Weeds often occur at the same time as fragile crop seedlings and sneak between plants as the crop grows. How can farmers kill them without harming crops?

Seed and chemical companies have developed two main technologies to prevent soil and foliar application of herbicides to harm crops: genetically modified herbicide-tolerant crops; and safeners, selectively and mystically - protect certain crops from damage Chemicals. In a new study at the University of Illinois, the researchers identified genes and metabolic pathways that lead to the safety of grain sorghum.

This discovery has played a big role in explaining how security personnel operate. According to my co-author of the weed scientist Dean Riechers of the U of I Crop Science Department and the frontier research in plant science, scientists accidentally discovered safeners in the late 1940s. Tomato plants grown in the greenhouse were inadvertently exposed to synthetic plant hormones during the experiment. Tomatoes are not exposed to the symptoms of the hormone itself, but when a herbicide is sprayed, they are not harmed. Without fully understanding how they worked, the researchers began trying to find more "herbicide antidote" before commercializing the first corn safener (methylene chloride) in 1971.

Today, after nearly 50 years of commercial use of corn, rice, wheat and grain sorghum, safeners remain a mystery. According to Riechers, the existence of synthetic chemicals that selectively protect high-value cereal crops rather than broad-leaved crops or weeds is fascinating, but not intuitive. Finding out how protection mechanisms in cereal crops can be turned on can help scientists play a protective role in broad-leaved crops such as soybeans and cotton.

Riechers said: "The finding of a safener for dicotyledonous crops will be the Holy Grail."

However, the first step is to understand what happens inside the cell when the grain crop is exposed to a safener. In the previous grain sorghum trial, the team found a significant increase in the production of glutathione S-transferase (GSTs). These important enzymes present in all organisms are rapidly detoxified before herbicides and other foreign chemicals can cause damage. But this did not greatly reduce the scope of the haystack.