Stripe rust effector Pst03724 modulates host immunity by inhibiting NAD kinase activation by a calmodulin

Yanfeng Wang; Cong Liu; Yuanyang Qin; Yuanyuan Du; Chao Song; Zhensheng Kang; Jia Guo; Jun Guo

doi:10.1093/plphys/kiae112

Stripe rust effector Pst03724 modulates host immunity by inhibiting NAD kinase activation by a calmodulin

Plant Physiol. 2024 Mar 5:kiae112. doi: 10.1093/plphys/kiae112. Online ahead of print.

Authors

Yanfeng Wang¹, Cong Liu¹, Yuanyang Qin¹, Yuanyuan Du¹, Chao Song¹, Zhensheng Kang¹, Jia Guo¹, Jun Guo¹

Affiliation

¹ State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, P R China.

PMID: 38441329
DOI: 10.1093/plphys/kiae112

Abstract

Puccinia striiformis f. sp. tritici (Pst) secretes effector proteins that enter plant cells to manipulate host immune processes. In this report we present an important Pst effector, Pst03724, whose mRNA expression level increases during Pst infection of wheat (Triticum aestivum). Silencing of Pst03724 reduced the growth and development of Pst. Pst03724 targeted the wheat calmodulin TaCaM3-2B, a positive regulator of wheat immunity. Subsequent investigations revealed that Pst03724 interferes with the TaCaM3-2B-NAD kinase TaNADK2 association and thus inhibits the enzyme activity of TaNADK2 activated by TaCaM3-2B. Knocking down TaNADK2 expression by virus-mediated gene silencing (VIGS) significantly increased fungal growth and development, suggesting a decrease in resistance against Pst infection. In conclusion, our findings indicate that Pst effector Pst03724 inhibits the activity of NAD kinase by interfering with the TaCaM3-2B-TaNADK2 association, thereby facilitating Pst infection.

Keywords: Puccinia striiformis f. sp. tritici; NAD kinase (NADK); calmodulin (CaM); effector; reactive oxygen species (ROS); wheat (Triticum aestivum).