PhD defence of Qi Zheng: Dissecting Gpa2‐mediated immune signaling pathways involved in resistance to the potato cyst nematode Globodera pallida
Potato NLR immune receptor Gpa2 confers resistance to potato cyst nematode Globodera pallida. Gpa2 is able to recognize its corresponding effector GpRBP-1 and trigger RanGAP2-dependent cell death response in Nicotiana benthamia leaves. So far, Gpa2 is the only intracellular nematode NLR for which its matching effector is identified, making Gpa2 a great model to study molecular mechanisms underlying nematode detection and defense activation. However, the molecular knowledge involved in Gpa2 activation and downstream signaling pathways is still fragmented. In this thesis, we investigated the role of different subcellular compartments in Gpa2 function and how RanGAP2 regulates Gpa2 activity at the cellular level. In addition, we identified two novel co-factors of Gpa2, which contribute to Gpa2-mediated immune responses. Eventually, we performed comparative transcriptome analysis on G. pallida infected potato roots upon Gpa2 activation to further explore the genes and potential signaling pathways involved in Gpa2-mediated resistance.