Karrikin

Chemical structures of karrikins (KAR1, KAR2, KAR3, and KAR4)

Karrikins are a group of plant growth regulators found in the smoke of burning plant material.[1][2] Karrikins help stimulate seed germination and plant development because they mimic a signaling hormone known as strigolactone. Strigolactones are hormones that help increase growth of symbiotic arbuscular mycorrhizal fungi in the soil, which enhances plant growth and leads to an increase in plant branching.[3][4]

Smoke from wildfires or bushfires has been known for a long time to stimulate the germination of seeds.[5][6] In 2004, the butenolide karrikinolide (KAR1) was shown to be responsible for this effect.[7] Later, several closely related compounds were discovered in smoke, and are collectively known as karrikins.[2]

  1. ^ Flematti GR, Dixon KW, Smith SM (December 2015). "What are karrikins and how were they 'discovered' by plants?". BMC Biology. 13 (1): 108. doi:10.1186/s12915-015-0219-0. PMC 4687367. PMID 26689715.
  2. ^ a b Chiwocha SD, Dixon KW, Flematti GR, Ghisalberti EL, Merritt DJ, Nelson DC, et al. (2009-10-01). "Karrikins: A new family of plant growth regulators in smoke". Plant Science. 177 (4): 252–256. doi:10.1016/j.plantsci.2009.06.007.
  3. ^ "Strigolactone - Latest research and news | Nature". www.nature.com. Retrieved 2020-04-26.
  4. ^ Andreo-Jimenez B, Ruyter-Spira C, Bouwmeester HJ, Lopez-Raez JA (2015-09-01). "Ecological relevance of strigolactones in nutrient uptake and other abiotic stresses, and in plant-microbe interactions below-ground". Plant and Soil. 394 (1): 1–19. doi:10.1007/s11104-015-2544-z.
  5. ^ Halford B (2010). "Smoke Signals". Chemical & Engineering News. 88 (15): 37–8. doi:10.1021/cen-v088n015.p037.
  6. ^ Nelson DC, Flematti GR, Ghisalberti EL, Dixon KW, Smith SM (2012-06-02). "Regulation of seed germination and seedling growth by chemical signals from burning vegetation". Annual Review of Plant Biology. 63 (1): 107–30. doi:10.1146/annurev-arplant-042811-105545. PMID 22404467.
  7. ^ Flematti GR, Ghisalberti EL, Dixon KW, Trengove RD (August 2004). "A compound from smoke that promotes seed germination". Science. 305 (5686): 977. doi:10.1126/science.1099944. PMID 15247439. S2CID 42979006.