title: HOMEODOMAIN PROTEIN 1 is required for jasmonate-mediated glandular trichome initiation in Artemisia annua.
abstract: Glandular trichomes are generally considered biofactories that produce valuable chemicals. Increasing glandular trichome density is a very suitable way to improve the productivity of these valuable metabolites, but little is known about the regulation of glandular trichome formation. Phytohormone jasmonate (JA) promotes glandular trichome initiation in various plants, but its mechanism is also unknown. By searching transcription factors regulated by JA in Artemisia annua, we identified a novel homeodomain-leucine zipper transcription factor, HOMEODOMAIN PROTEIN 1 (AaHD1), which positively controls both glandular and nonglandular trichome initiations. Overexpression of AaHD1 in A. annua significantly increased glandular trichome density without harming plant growth. Consequently, the artemisinin content was improved. AaHD1 interacts with A. annua jasmonate ZIM-domain 8 (AaJAZ8), which is a repressor of JA, thereby resulting in decreased transcriptional activity. AaHD1 knockdown lines show decreased sensitivity to JA on glandular trichome initiation, which indicates that AaHD1 plays an important role in JA-mediated glandular trichome initiation. We identified a new transcription factor that promotes A. annua glandular trichome initiation and revealed a novel molecular mechanism by which a homeodomain protein transduces JA signal to promote glandular trichome initiation. Our results also suggested a connection between glandular and nonglandular trichome formations.
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Tingxiang
authors.initials: T
authors.lastname: Yan
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Minghui
authors.initials: M
authors.lastname: Chen
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Qian
authors.identifier: http://orcid.org/0000-0002-4621-4659
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Fu
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Qifang
authors.initials: Q
authors.lastname: Pan
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Yueli
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Pu
authors.initials: P
authors.lastname: Shi
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Zongyou
authors.initials: Z
authors.lastname: Lv
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Ya-Nan
authors.initials: YN
authors.lastname: Ma
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Hao
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Xiaofen
authors.initials: X
authors.lastname: Sun
authors.affiliation: Joint International Research Laboratory of Metabolic & Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: Kexuan
authors.initials: K
authors.lastname: Tang
mesh_terms: D031172:Artemisia annua / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism*; D003517:Cyclopentanes / Q000494:pharmacology*; D055785:Gene Knockdown Techniques; D008954:Models, Biological; D038081:Organogenesis / Q000187:drug effects; D054883:Oxylipins / Q000494:pharmacology*; D010802:Phylogeny; D018515:Plant Leaves / Q000648:ultrastructure; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D030821:Plants, Genetically Modified; D000072417:Protein Domains; D014158:Transcription, Genetic / Q000187:drug effects; D064201:Trichomes / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid
keywords: 
  Artemisia annua
  ; AaHD1; JAZ protein; glandular trichome; jasmonate (JA); transcription factor