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Aa MYB 1 and its orthologue At MYB 61 affect terpene metabolism and trichome development in Artemisia annua and Arabidopsis thaliana
Author(s) -
MatíasHernández Luis,
Jiang Weimin,
Yang Ke,
Tang Kexuan,
Brodelius Peter E.,
Pelaz Soraya
Publication year - 2017
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13509
Subject(s) - trichome , artemisia annua , myb , arabidopsis thaliana , biology , mutant , transcription factor , botany , microbiology and biotechnology , biochemistry , artemisinin , gene , malaria , immunology , plasmodium falciparum
Summary The effective anti‐malarial drug artemisinin ( AN ) isolated from Artemisia annua is relatively expensive due to the low AN content in the plant as AN is only synthesized within the glandular trichomes. Therefore, genetic engineering of A. annua is one of the most promising approaches for improving the yield of AN . In this work, the Aa MYB 1 transcription factor has been identified and characterized. When Aa MYB 1 is overexpressed in A. annua , either exclusively in trichomes or in the whole plant, essential AN biosynthetic genes are also overexpressed and consequently the amount of AN is significantly increased. Artemisia Aa MYB 1 constitutively overexpressing plants displayed a greater number of trichomes. In order to study the role of Aa MYB 1 on trichome development and other possibly connected biological processes, Aa MYB 1 was overexpressed in Arabidopsis thaliana . To support our findings in Arabidopsis thaliana , an Aa MYB 1 orthologue from this model plant, At MYB 61 , was identified and atmyb61 mutants characterized. Both Aa MYB 1 and At MYB 61 affected trichome initiation, root development and stomatal aperture in A. thaliana . Molecular analyses indicated that two crucial trichome activator genes are misexpressed in atmyb61 mutant plants and in plants overexpressing Aa MYB 1 . Furthermore, Aa MYB 1 and At MYB 61 are also essential for gibberellin ( GA ) biosynthesis and degradation in both species by positively affecting the expression of the enzymes that convert GA 9 into the bioactive GA 4 as well as the enzymes involved in the degradation of GA 4 . Overall, these results identify Aa MYB 1/At MYB 61 as a key component of the molecular network that connects important biosynthetic processes, and reveal its potential value for AN production through genetic engineering.