The plant signal peptide CLE7 induces plant defense response against viral infection in Nicotiana benthamiana.

In plants, small peptides are important players in the plant stress response, yet their function in plant antiviral responses remains poorly understood. Here, we identify that the plant small peptide, CLAVATA3/ESR-RELATED 7 (CLE7), enhances plant resistance to Chinese wheat mosaic virus infection in Nicotiana (N.) benthamiana. Subsequent investigations demonstrate that CLE7 recognizes receptor kinase NbPXC3 to control the plant antiviral response. Moreover, CLE7-NbPXC3 signaling induces NbMKK2-controlled NbMPK4 phosphorylation, resulting in phosphorylation of the transcription factor NbEDT1. NbEDT1 phosphorylation is involved in the transcriptional activity of NbNCED3, which is a rate‐limiting enzyme in ABA (Abscisic Acid) biosynthesis. Moreover, CLE7 activates broad-spectrum disease resistance to multiple RNA viral infections. Our study indicates that CLE7 induces a plant antiviral response though a series of immune signal transductions in N. benthamiana and provides a foundation for the exploration of efficient viral disease management methods based on plant small peptides.

在植物界，小肽作为植物对胁迫反应的关键参与者，然而其在植物抗病毒反应中的功能尚不明确。本研究揭示了植物小肽CLAVATA3/ESR-RELATED 7（CLE7）能够增强拟南芥（N. benthamiana）对小麦花叶病毒感染的抵抗力。后续研究证实，CLE7通过识别受体激酶NbPXC3来调控植物的抗病毒反应。此外，CLE7-NbPXC3信号通路诱导NbMKK2控制的NbMPK4磷酸化，进而导致转录因子NbEDT1的磷酸化。NbEDT1的磷酸化参与了NbNCED3的转录活性，而NbNCED3是ABA（脱落酸）生物合成的限速酶。此外，CLE7激活了对多种RNA病毒感染的广谱抗病性。本研究表明，CLE7通过拟南芥中的系列免疫信号传导诱导植物抗病毒反应，并为基于植物小肽的高效病毒病管理方法的探索奠定了基础。