Hao, JingjieYang, YingFutrell, StephanieKelly, Elizabeth A.Lorts, Claire M.Nebie, BalouaRuno, StevenYang, JinliangAlvarez, SophieLasky, Jesse R.Schachtman, Daniel P.2023-07-122023-07-122023Hao, J., Yang, Y., Futrell, S., Kelly, E. A., Lorts, C. M., Nebie, B., ... & Schachtman, D. P. (2023). CRISPR/Cas9-Mediated Mutagenesis of Carotenoid Cleavage Dioxygenase (CCD) Genes in Sorghum Alters Strigolactone Biosynthesis and Plant Biotic Interactions. Phytobiomes Journal, PBIOMES-08.https://doi.org/10.1094/PBIOMES-08-22-0053-Rhttp://ir-library.ku.ac.ke/handle/123456789/26175articleStrigolactones are a group of small molecules that play criticalroles in plant developmental processes and root bioticinteractions. Strigolactones are agronomically important due totheir role as a signal for the germination of a parasitic weed(Strigaspp.) that reduces yields of cereal crops worldwide. Toidentify the genes encoding strigolactones in sorghum and theirfunction, we characterized two CRISPR/Cas9-mediated geneknockouts ofcarotenoid cleavage dioxygenase 8(CCD8) genes(SbCCD8aandSbCCD8b), which have been shown in otherplant species to be involved in strigolactone biosynthesis.Although strigolactones are important for the parasitization ofsorghum in Africa, the functions of members of the CCD8 familyhave not been characterized. The impact of the knockouts onstrigolactone production, plant growth and development,resistance to the parasitic weedStriga, and the root-associatedmicrobiomes were investigated in this study. The resultsrevealed that knockout ofSbCCD8genes in sorghumsignificantly reduced orobanchol production andStrigagermination. Strigolactone deficiency altered the shoot and rootarchitecture and reduced grain yield of sorghum. The knockoutof theSbCCD8bgene significantly affected the rhizospherebacterial diversity and community composition at sorghum plantgrain-fill stage due to the abolition of orobanchol exudation fromroots. Reduced amounts of orobanchol in root exudates alsoinfluenced root-associated fungal taxa abundance. Our findingsprovide new insights into potentially sustainable approaches forthe recruitment of beneficial microbes and for parasitic weedcontrol through manipulation of strigolactone production insorghum.enCCDmicrobiomesorghumStrigolactoneArticle