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HOMEODOMAIN PROTEIN 1 is required for jasmonate‐mediated glandular trichome initiation in Artemisia annua
Author(s) -
Yan Tingxiang,
Chen Minghui,
Shen Qian,
Li Ling,
Fu Xueqing,
Pan Qifang,
Tang Yueli,
Shi Pu,
Lv Zongyou,
Jiang Weimin,
Ma Yanan,
Hao Xiaolong,
Sun Xiaofen,
Tang Kexuan
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14205
Subject(s) - trichome , artemisia annua , transcription factor , biology , jasmonate , microbiology and biotechnology , homeobox , gene knockdown , botany , gene , biochemistry , artemisinin , arabidopsis , malaria , mutant , immunology , plasmodium falciparum
Summary 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 (Aa HD 1), which positively controls both glandular and nonglandular trichome initiations. Overexpression of Aa HD 1 in A. annua significantly increased glandular trichome density without harming plant growth. Consequently, the artemisinin content was improved. Aa HD 1 interacts with A. annua jasmonate ZIM‐domain 8 (Aa JAZ 8), which is a repressor of JA , thereby resulting in decreased transcriptional activity. Aa HD 1 knockdown lines show decreased sensitivity to JA on glandular trichome initiation, which indicates that Aa HD 1 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.