Overexpression of a Novel NAC Domain-Containing Transcription Factor Gene (AaNAC1) Enhances the Content of Artemisinin and Increases Tolerance to Drought and Botrytis cinerea in Artemisia annua
Overexpression of a Novel NAC Domain-Containing Transcription Factor Gene (AaNAC1) Enhances the Content of Artemisinin and Increases Tolerance to Drought and Botrytis cinerea in Artemisia annua
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DOI：
10.1093/pcp/pcw118
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发表时间：
2016-09-01
影响因子：
4.9
通讯作者：
Tang, Kexuan
中科院分区：
文献类型：
--
作者：
Lv, Zongyou;Wang, Shu;Tang, Kexuan
NAC（NAM、ATAF 和 CUC）超家族是最大的植物特异性转录因子家族之一。 NAC转录因子在应对各种非生物胁迫中始终发挥着重要作用。从青蒿中克隆了一个含有完整开放阅读框（ORF）864 bp的NAC转录因子基因AaNAC1。 AaNAC1 的表达可以通过脱水、寒冷、水杨酸（SA）和茉莉酸甲酯（MJ）诱导，表明它可能是青蒿应激信号通路的关键调节因子。 AaNAC1 通过转化烟叶表皮细胞被证明定位于细胞核。当AaNAC1在青蒿中过表达时，青蒿素和二氢青蒿酸的含量分别增加了79%和150%。青蒿素生物合成途径基因，即紫穗槐-4,11-二烯合酶（ADS）、青蒿醛Delta 11（13）还原酶（DBR2）和醛脱氢酶1（ALDH1）的表达水平增加。双荧光素酶 (dual-LUC) 检测表明 AaNAC1 可以在体内激活 ADS 的转录。转基因青蒿表现出增强的干旱耐受性和灰霉病抗性。当AaNAC1在拟南芥中过表达时，转基因拟南芥明显更能耐受干旱。转基因拟南芥显示出对灰霉病菌的抗性增强。这些结果表明AaNAC1有可能用于转基因育种，以提高青蒿的青蒿素含量和耐旱性。
The NAC (NAM, ATAF and CUC) superfamily is one of the largest plant-specific transcription factor families. NAC transcription factors always play important roles in response to various abiotic stresses. A NAC transcription factor gene AaNAC1 containing a complete open reading frame (ORF) of 864 bp was cloned from Artemisia annua. The expression of AaNAC1 could be induced by dehydration, cold, salicylic acid (SA) and methyl jasmonate (MJ), suggesting that it might be a key regulator of stress signaling pathways in A. annua. AaNAC1 was shown to be localized to the nuclei by transforming tobacco leaf epidermal cells. When AaNAC1 was overexpressed in A. annua, the content of artemisinin and dihydroartemisinic acid was increased by 79% and 150%, respectively. The expression levels of artemisinin biosynthetic pathway genes, i.e. amorpha-4,11-diene synthase (ADS), artemisinic aldehyde Delta 11(13) reductase (DBR2) and aldehyde dehydrogenase 1 (ALDH1), were increased. Dual luciferase (dual-LUC) assays showed that AaNAC1 could activate the transcription of ADS in vivo. The transgenic A. annua exhibited increased tolerance to drought and resistance to Botrytis cinerea. When AaNAC1 was overexpressed in Arabidopsis, the transgenic Arabidopsis were markedly more tolerant to drought. The transgenic Arabidopsis showed increased resistance to B. cinerea. These results indicate that AaNAC1 can potentially be used in transgenic breeding for improving the content of artemisinin and drought tolerance in A. annua.