and Suppress pv. -Induced Hypersensitive Response and Non-host Resistance in Tomato.

Mechanisms underlying plant non-host resistance to pv. (), the pathogen causing rice leaf streak disease, are largely unknown. Cyclic nucleotide-gated ion channels (CNGCs) are calcium-permeable channels that are involved in various biological processes including plant resistance. In this study, functions of two tomato genes and in non-host resistance to were analyzed. Silencing of and in tomato significantly enhanced -induced hypersensitive response (HR) and non-host resistance, demonstrating that both and negatively regulate non-host resistance related HR and non-host resistance to in tomato. Silencing of and strikingly increased -induced callose deposition and strongly promoted both -induced and flg22-elicited HO, indicating that these two repress callose deposition and ROS accumulation to attenuate non-host resistance and PAMP-triggered immunity (PTI). Importantly, silencing of and apparently compromised cytosolic Ca accumulation, implying that SlCNGC1 and SlCNGC14 function as Ca channels and negatively regulate non-host resistance and PTI-related responses through modulating cytosolic Ca accumulation. seemed to play a stronger regulatory role in the non-host resistance and PTI compared to . Our results reveal the contribution of CNGCs and probably also Ca signaling pathway to non-host resistance and PTI.