The Same against Many: AtCML8, a Ca Sensor Acting as a Positive Regulator of Defense Responses against Several Plant Pathogens.

Calcium signals are crucial for the activation and coordination of signaling cascades leading to the establishment of plant defense mechanisms. Here, we studied the contribution of CML8, an Arabidopsis calmodulin-like protein in response to and to pathogens with different lifestyles, such as pv. and . We used pathogenic infection assays, gene expression, RNA-seq approaches, and comparative analysis of public data on knockdown and overexpressing Arabidopsis lines to demonstrate that CML8 contributes to defense mechanisms against pathogenic bacteria and oomycetes. gene expression is finely regulated at the root level and manipulated during infection with , and overexpression confers better plant tolerance. To understand the processes controlled by CML8, genes differentially expressed at the root level in the first hours of infection have been identified. Overexpression of also confers better tolerance against and and most of the genes differentially expressed in response to are differentially expressed in these different pathosystems. Collectively, CML8 acts as a positive regulator against and against other vascular or root pathogens, suggesting that CML8 is a multifunctional protein that regulates common downstream processes involved in the defense response of plants to several pathogens.