Hormone discovery may boost plant defenses against disease

Scientists have finally learned how a common plant hormone, jasmonate, responds to insects and diseases. Michigan State University researchers Sheng Yang He and Gregg Howe worked with Washington State University on the project. Until now, scientists did not know the steps that convert the hormone’s signal into genetic and cellular action.

“Now that we know what the active signals are and have identified the key regulatory proteins -- the JAZ proteins -- involved, the hope is to either genetically modify plants or develop compounds that mimic the jasmonate hormone,” Howe said. “The research may help scientists engineer plants for increased resistance to insects and pathogens.”

Jasmonate is the last major plant hormone to have its signaling process revealed. Initial research by WSU researchers identified the family of proteins -- dubbed JAZ proteins -- that are critical to plants receiving and responding to the jasmonate signal.

Independent of the WSU work, Howe and He used Arabidopsis, a common lab plant, and tomato plants to determine how JAZ proteins work. Their experiments showed that the jasmonate signal causes direct interaction between JAZ proteins and a second protein complex, SCFCOI1, that works to eliminate the JAZ protein so that the plant can mount a defensive response.

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For more: Gregg Howe, Michigan State University, (517) 355-5159; howeg@msu.edu. Sheng Yang He, (517) 353-9181; hes@msu.edu.