Abstract:
Plant Nucleotide binding-Leucine rich repeat (NLR) proteins play a significant role in
pathogen detection and the activation of effector-triggered immunity. NLR regulation has
mainly been studied at a protein level, with large knowledge gaps remaining regarding
the transcriptional control of NLR genes. The mis-regulation of NLR gene expression may
lead to the inability of plants to recognize pathogen infection, lower levels of immune
response activation, and ultimately plant susceptibility. This highlights the importance of
understanding all aspects of NLR regulation. Three main mechanisms have been shown
to control NLR expression: epigenetic modifications, cis elements which bind transcription
factors, and post-transcriptional modifications. In this review, we aim to provide an
overview of these mechanisms known to control NLR expression, and those which
contribute toward successful immune responses. Furthermore, we discuss how pathogens
can interfere with NLR expression to increase pathogen virulence. Understanding how
these molecular mechanisms control NLR expression would contribute significantly toward
building a complete picture of how plant immune responses are activated during pathogen
infection—knowledge which can be applied during crop breeding programs aimed to
increase resistance toward numerous plant pathogens.
