Peroxisomes are redox nodes playing a diverse range of roles in cell functionality and in the perception of and responses to changes in their environment.

Complex signalling pathways are involved in plant protection against single and combined stresses. Plants are able to coordinate genome-wide transcriptional reprogramming and display a unique program of transcript responses to a combination of stresses which differ from single stresses. However, a significant overlap between pathways and some defence genes in the form of shared and general stress-responsive genes appears to be commonly involved in responses to multiple biotic and abiotic stresses. Reactive oxygen and nitrogen species (ROS/RNS), as well as redox signals, are key molecules involved at the crossroads of perceptions of different stress factors and regulation of both specific and general plant responses to biotic and abiotic stress. In this review, we focus on crosstalk between plant responses to biotic and abiotic stresses, in addition to possible plant protection against pathogens caused by previous abiotic stress. Bioinformatic analyses of transcriptome data from Cd- and fungal pathogen-treated plants focusing on redox gene ontology (GO) categories were carried out to gain a better understanding of common plant responses to abiotic and biotic stresses. The role of ROS and RNS in the complex network involved in plant responses to changes in their environment is also discussed.

Reactive oxygen and nitrogen species (ROS/RNS) are signaling molecules involved in a plethora of physiological processes in plants. Especially, ROS and nitric oxide (NO) are key players that are required for programmed cell death (PCD). The PCD associated with the hypersensitive response (HR) has been well characterized and the role of HO and NO as key signaling molecules inducing HR has been established. Localization of ROS and NO production in plant tissues in response to pathogens can be imaged by confocal laser microscopy by using specific fluorescent probes. Deciphering the time and spatial regulation of ROS and NO is very important to establish the cellular response of plants to adverse conditions. This chapter is mainly focused on the imaging of ROS and RNS accumulation in vivo in plant tissues undergoing PCD.

No abstract