Scala Alessandra, Mirabella Rossana, Goedhart Joachim, de Vries Michel, Haring Michel A, Schuurink Robert C
Department of Plant Physiology, Swammerdam Institute for Life Sciences, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
Department of Molecular Cytology, Swammerdam Institute for Life Sciences, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
Plant Mol Biol. 2017 Nov;95(4-5):399-409. doi: 10.1007/s11103-017-0659-8. Epub 2017 Sep 16.
This work adds a new player, HER2, downstream of the perception of E-2-hexenal, a green leaf volatile, and shows that E-2-hexenal specifically changes the redox status of the mitochondria. It is widely accepted that plants produce and respond to green leaf volatiles (GLVs), but the molecular components involved in transducing their perception are largely unknown. The GLV E-2-hexenal inhibits root elongation in seedlings and, using this phenotype, we isolated E-2-hexenal response (her) Arabidopsis thaliana mutants. Using map-based cloning we positioned the her2 mutation to the At5g63620 locus, resulting in a phenylalanine instead of serine on position 223. Knockdown and overexpression lines of HER2 confirmed the role of HER2, which encodes an oxidoreductase, in the responsiveness to E-2-hexenal. Since E-2-hexenal is a reactive electrophile species, which are known to influence the redox status of cells, we utilized redox sensitive GFP2 (roGFP2) to determine the redox status of E-2-hexenal-treated root cells. Since the signal peptide of HER2 directed mCherry to the mitochondria, we targeted the expression of roGFP2 to this organelle besides the cytosol. E-2-hexenal specifically induced a change in the redox status in the mitochondria. We did not see a difference in the redox status in her2 compared to wild-type Arabidopsis. Still, the mitochondrial redox status did not change with Z-3-hexenol, another abundant GLV. These results indicate that HER2 is involved in transducing the perception of E-2-hexenal, which changes the redox status of the mitochondria.
这项研究发现了一个新的参与者HER2，它位于绿叶挥发物E-2-己烯醛感知的下游，并表明E-2-己烯醛特异性地改变了线粒体的氧化还原状态。人们普遍认为植物会产生并对绿叶挥发物（GLVs）做出反应，但参与传递其感知的分子成分在很大程度上尚不清楚。GLV E-2-己烯醛会抑制幼苗的根伸长，利用这一表型，我们分离出了拟南芥E-2-己烯醛反应（her）突变体。通过图位克隆，我们将her2突变定位到At5g63620位点，导致第223位的丝氨酸被苯丙氨酸取代。HER2的敲低和过表达株系证实了HER2（一种编码氧化还原酶）在对E-2-己烯醛的反应中的作用。由于E-2-己烯醛是一种活性亲电物质，已知会影响细胞的氧化还原状态，我们利用氧化还原敏感的绿色荧光蛋白2（roGFP2）来确定经E-2-己烯醛处理的根细胞的氧化还原状态。由于HER2的信号肽将mCherry导向线粒体，除了细胞质外，我们还将roGFP2的表达靶向到这个细胞器。E-2-己烯醛特异性地诱导了线粒体氧化还原状态的变化。与野生型拟南芥相比，我们没有观察到her2中氧化还原状态的差异。然而，线粒体氧化还原状态并没有随着另一种丰富的GLV Z-3-己烯醇而改变。这些结果表明，HER2参与传递E-2-己烯醛的感知，从而改变线粒体的氧化还原状态。
