Identification of a Putative Voltage-Gated Ca²⁺ Permeable Channel Involved in Elicitor-Induced Defense Responses in Rice Cells

Abstract

Physiological evidences suggest that transient membrane depolarization and Ca²⁺ influx through the plasma membrane triggered by elicitors play important roles in defense signaling. However, molecular bases for the Ca²⁺ influx and its regulation remain largely unknown in plants. We identified a putative voltage-gated Ca²⁺ channel in rice and developed its overexperssors as well as its retrotransposon-insertional knockout mutant. The overexpressing cells showed enhanced sensitivity to a proteiaceous fungal elicitor that induces hypersensitive cell death, whereas the elicitor-induced defense responses were strongly suppressed in the knockout cells. Possible physiological roles of the putative voltage-gated Ca²⁺ permeable channel in elicitor-mediated defense responses will be discussed.