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. Issue 4 (1st March 2013)

• Record Type: Journal Article
• Authors: Lu, Xu; Zhang, Ling; Zhang, Fangyuan; Jiang, Weimin; Shen, Qian; Zhang, Lida; Lv, Zongyou; Wang, Guofeng; Tang, Kexuan
• Is Part Of: New phytologist. Volume 198:Issue 4(2013)
• Page Start: 1191
• Page End: 1202
• Publication Date: 2013-03-01
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12207
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12207-abs-0001"> <title>Summary</title> <p> <list id="nph12207-list-0001" list-type="bullet"> <list-item> <p>Six transcription factors of APETALA2/ethylene‐response factor (AP2/ERF) family were cloned and analyzed in <italic>Artemisia annua</italic>. Real‐time quantitative polymerase chain reaction (RT‐Q‐PCR) showed that <italic>AaORA</italic> exhibited similar expression patterns to those of amorpha‐4, 11‐diene synthase gene (<italic>ADS</italic>), cytochrome P450‐dependent hydroxylase gene (<italic>CYP71AV1</italic>) and double bond reductase 2 gene (<italic>DBR2</italic>) in different tissues of <italic>A. annua</italic>.</p> </list-item> <list-item> <p> <italic>AaORA</italic> is a trichome‐specific transcription factor, which is expressed in both glandular secretory trichomes (GSTs) and nonglandular T‐shaped trichomes (TSTs) of <italic>A. annua</italic>. The result of subcellular localization shows that <italic>AaORA</italic> is targeted to the nuclei and the cytoplasm.</p> </list-item> <list-item> <p>Overexpression and RNA interference (RNAi) of <italic>AaORA</italic> in <italic>A. annua</italic> regulated, positively and significantly, the expression levels of <italic>ADS</italic>, <italic> CYP71AV1</italic>, <italic> DBR2</italic> and <italic>AaERF1</italic>. 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 <italic>AaORA</italic> is a positive regulator in the biosynthesis of artemisinin.</p> </list-item> <list-item> <p>Overexpression of <italic>AaORA</italic> in <italic>Arabidopsis thaliana</italic> increased greatly the transcript levels of the defense marker genes <italic>PLANT DEFENSIN1.2</italic> (<italic>PDF1.2</italic>), <italic>HEVEIN‐LIKE PROTEIN</italic> (<italic>HEL</italic>) and <italic>BASIC CHITINASE</italic> (<italic>B‐CHI</italic>). After inoculation with <italic>Botrytis cinerea</italic>, the phenotypes of <italic>AaORA</italic> overexpression in <italic>A. thaliana</italic> and <italic>AaORA </italic>RNAi in <italic>A. annua</italic> demonstrate that <italic>AaORA</italic> is a positive regulator of disease resistance to <italic>B. cinerea</italic>.</p> </list-item> </list> </p> </abstract>