LSD3 mediates the oxidative stress response through fine-tuning APX2 activity and the NF-YC15-GSTs module in cassava

第一作者：Hongqiu Zeng

第一单位：海南大学

通讯作者：Haitao Shi

 Abstarct 

背景+问题：Reactive oxygen species (ROS) overproduction leads to oxidative damage under almost all stress conditions. Lesion-Simulating Disease (LSD), a zinc finger protein, is an important negative regulator of ROS accumulation and cell death in plants. However, the in vivo role of LSD in cassava (Manihot esculenta) and the underlying molecular mechanisms remain elusive. 

在几乎所有的胁迫条件下，活性氧物质（ROS）的过量产生都会导致氧化损伤。锌指蛋白LSD是植物体内ROS积累和细胞死亡的重要负调节因子。然而，LSD在木薯中的作用及其潜在分子机制仍不清楚。

主要发现：Here, we found that MeLSD3 is essential for the oxidative stress response in cassava. 

本文中，作者发现MeLSD3对木薯的氧化应激响应至关重要。

结果1-LSD3与APX2：MeLSD3 physically interacted with ascorbate peroxidase 2 (MeAPX2), thereby promoting its enzymatic activity. 

MeLSD3能够与抗坏血酸过氧化物酶MeAPX2发生物理互作，从而提高后者的酶活性。

结果2-LSD3与NF-YC15：In addition, MeLSD3 also interacted with the nuclear factor YC15 (MeNF-YC15), which also interacted with nuclear factor YA2/4 (MeNF-YA2/4) and nuclear factor YB18 (MeNF-YB18) to form an MeNF-YC15–MeNF-YA2/4–MeNF-YB18 complex. 

此外，MeLSD3还会与核因子MeNF-YC15互作，后者会与核因子MeNF-YA2/4和MeNF-YB18互作，从而形成MeNF-YC15–MeNF-YA2/4–MeNF-YB18复合物。

结果3-LSD3通过GST调控NF-YC15复合物：Notably, MeLSD3 positively modulated the transcriptional activation of the MeNF-YC15–MeNF-YA2/4–MeNF-YB18 complex by interacting with the CCAAT boxes of the promoters of glutathione S-transferases U37/U39 (MeGST-U37/U39), activating their transcription. When one or both of MeLSD3 and the MeNF-YC15–MeNF-YA2/4–MeNF-YB18 complex were co-silenced, cassava showed decreased oxidative stress resistance, while overexpression of MeGST-U37/U39 alleviated the oxidative stress-sensitive phenotype of these silenced plants. 

值得注意的是，MeLSD3通过与谷胱甘肽S-转移酶编码基因MeGST-U37/U39启动子上的CCAAT boxes互作，激活MeGST-U37/U39基因的转录，从而正向调控MeNF-YC15–MeNF-YA2/4–MeNF-YB18复合物的转录激活。当MeLSD3和MeNF-YC15–MeNF-YA2/4–MeNF-YB18复合物中的一个或两个共同沉默时，木薯的抗氧化能力降低，而MeGST-U37/U39的过度表达能够减缓这些沉默株系的氧化应激易敏表型。

结论：This study illustrates the dual roles of MeLSD3 in promoting MeAPX2 activity and MeNF-YC15–MeGST-U37/U39 regulation, which underlie the oxidative stress response in cassava.

本文的研究结果揭示了木薯LSD3基因在促进MeAPX2活性和MeNF-YC15–MeGST-U37/U39调节中的双重作用，从而构成了木薯氧化应激响应的分子基础。

** 施海涛 **

doi: https://doi.org/10.1111/tpj.15749

Journal: the plant journal

 First Published: March 30, 2022