Plants have evolved several mechanisms to control their development and their defence against disease. One key mechanism, called RNA silencing, switches genes on and off during plant development, and stops pathogens such as fungi and viruses. Another key mechanism involves a network of plant hormones that control plant growth and trigger the plant's defence system when under attack. The EU-funded SILENCING HORMONES (The role of RNA silencing In regulation of jasmonate hormone signalling) project wanted to find out if plant RNA silencing and hormone pathways are interlinked. SILENCING HORMONES was particularly interested in seeing if RNA silencing controls signalling by the hormone jasmonate, which controls processes ranging from photosynthesis to reproduction. Researchers first studied a group of proteins called transcription factors that are known to regulate RNA silencing to see if they control jasmonate production too. The project found that these transcription factors regulated multiple hormone pathways, by binding to thousands of genes and switching them off. Evidence suggests that the mechanisms by which RNA silencing regulates gene activity are in turn controlled by hormones like jasmonate. This dynamic regulatory network involving feedback into RNA silencing by jasmonate signalling will be useful for understanding how plants coordinate complex defence and development behaviour. It will also be valuable for breeders aiming to improve plant defence and growth.
Plant development, RNA silencing, jasmonate, hormone signalling, transcription factors