Calcium signaling in plant-microbe interaction

Introduction

Calcium ion (Ca²⁺) is an important second messenger involved in many signaling pathways in plants. The intracellular concentration of Ca²⁺ connects the extracellular stimuli, including the signal of microbes, to intracellular and allow the respond in plants. Since Ca²⁺ cannot be synthesized or degraded by plant, its concentration in the cytoplasm of a plant cell ([Ca²⁺]_cyt) is completely dependent on the balance of its entry and efflux process. The concentration is regulated tightly by various membrane proteins, such as Ca²⁺ permeable channels, transporters, and Ca²⁺ pumps. Different microbe signals trigger distinctive Ca²⁺ elevation patterns, referred to as Ca²⁺ signature, that can be different from each other from various aspects: amplitude, duration, frequency, spatial distribution, and times of cycle in [Ca²⁺]_cyt changes. The Ca²⁺ signature produced by microbe signal can be decoded by downstream effectors and will result in transcriptional reprogramming of the defense or symbiosis-related genes by the transcription factors, causing different responses by plants.

References

Edited by Yueqi Song, student of Joan Slonczewski for BIOL 116 Information in Living Systems, 2021, Kenyon College.