AaORA, a trichome-specific AP2/ERF transcription factor of Artemisia annua, is a positive regulator in the artemisinin biosynthetic pathway and in disease resistance to Botrytis cinerea
Article first published online: 1 MAR 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 198, Issue 4, pages 1191–1202, June 2013
How to Cite
Lu, X., Zhang, L., Zhang, F., Jiang, W., Shen, Q., Zhang, L., Lv, Z., Wang, G. and Tang, K. (2013), AaORA, a trichome-specific AP2/ERF transcription factor of Artemisia annua, is a positive regulator in the artemisinin biosynthetic pathway and in disease resistance to Botrytis cinerea. New Phytologist, 198: 1191–1202. doi: 10.1111/nph.12207
- Issue published online: 7 MAY 2013
- Article first published online: 1 MAR 2013
- Manuscript Accepted: 30 JAN 2013
- Manuscript Received: 17 OCT 2012
- China ‘863’ Program. Grant Number: 2011AA100605
- China Transgenic Research Program. Grant Number: 2011ZX08002-001
- Ministry of Education
- artemisinin biosynthetic pathway;
- dihydroartemisinic acid;
- disease resistance to B. cinerea;
- secondary metabolism;
- trichome specific
- Six transcription factors of APETALA2/ethylene-response factor (AP2/ERF) family were cloned and analyzed in Artemisia annua. Real-time quantitative polymerase chain reaction (RT-Q-PCR) showed that AaORA exhibited similar expression patterns to those of amorpha-4,11-diene synthase gene (ADS), cytochrome P450-dependent hydroxylase gene (CYP71AV1) and double bond reductase 2 gene (DBR2) in different tissues of A. annua.
- AaORA is a trichome-specific transcription factor, which is expressed in both glandular secretory trichomes (GSTs) and nonglandular T-shaped trichomes (TSTs) of A. annua. The result of subcellular localization shows that AaORA is targeted to the nuclei and the cytoplasm.
- Overexpression and RNA interference (RNAi) of AaORA in A. annua regulated, positively and significantly, the expression levels of ADS, CYP71AV1, DBR2 and AaERF1. The up-regulated or down-regulated expression levels of these genes resulted in a significant increase or decrease in artemisinin and dihydroartemisinic acid. The results demonstrate that AaORA is a positive regulator in the biosynthesis of artemisinin.
- Overexpression of AaORA in Arabidopsis thaliana increased greatly the transcript levels of the defense marker genes PLANT DEFENSIN1.2 (PDF1.2), HEVEIN-LIKE PROTEIN (HEL) and BASIC CHITINASE (B-CHI). After inoculation with Botrytis cinerea, the phenotypes of AaORA overexpression in A. thaliana and AaORA RNAi in A. annua demonstrate that AaORA is a positive regulator of disease resistance to B. cinerea.