Nitric oxide (NO) is a signaling molecule involved in numerous physiological processes in
both animals and plants. The bioactivity of NO is mainly transduced via post-translational modification
of cysteine residues of proteins termed S-nitrosylation. Interestingly, a number of key regulatory
components in plant defense responses have been found to be regulated by S-nitrosylation making this
type of protein modification an important modulator of plant immunity. As a signaling molecule, NO
intimately interact with other important molecules such as reactive oxygen species. Since the
identification of NO in plants, increasing number of papers isbeing published in the area of NO biology
each year. Here, a collection of papers describing the role of NO in plant immunity has been brought
together to provide a bird's-eye view on the focus area.