AUTHOR=Wang Qing , Liu Heng , Zhang Min , Liu Shaohua , Hao Yujin , Zhang Yuanhu 

TITLE=MdMYC2 and MdERF3 Positively Co-Regulate α-Farnesene Biosynthesis in Apple

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.512844

DOI=10.3389/fpls.2020.512844

ISSN=1664-462X

ABSTRACT=<p>α-Farnesene, a sesquiterpene volatile compound plays an important role in plant defense and is known to be associated with insect attraction and with superficial scald of apple and pear fruits during cold storage. But the mechanism whereby transcription factors regulate apple α-farnesene biosynthesis has not been clarified. Here, we report that two transcription factors, MdMYC2 and MdERF3 regulated α-farnesene biosynthesis in apple fruit. Dual-luciferase assays and Y1H assays indicated that MdMYC2 and MdERF3 effectively trans-activated the <italic>MdAFS</italic> promoter. EMSAs showed that MdERF3 directly binds the DRE motif in the <italic>MdAFS</italic> promoter. Subsequently, overexpression of <italic>MdMYC2</italic> and <italic>MdERF3</italic> in apple calli markedly activated the transcript levels of <italic>MdHMGR2</italic> and <italic>MdAFS</italic>. Furthermore, transient overexpression of <italic>MdMYC2</italic> and <italic>MdERF3</italic> in apple fruit significantly increased <italic>MdAFS</italic> expression and hence, α-farnesene production. These results indicate that MdMYC2 and MdERF3 are positive regulators of α-farnesene biosynthesis and have important value in genetic engineering of α-farnesene production.</p>