Nitric oxide signaling in plants

Nitric oxide (NO) is now seen as a vitally important molecule in many biological systems. Once it was identified in mammalian systems in 1987 (Palmer et al., 1987) it was only a matter of time before researchers hunted for its presence in plants, with the first such reports being published in 1998 (Delledonne et al., 1998; Durner et al., 1998). Now 15 years later the interest in NO and its roles in plants is as eagerly investigated as ever, with an ever increasing number of papers published in the area each year. However, the field is not short of controversies, and it would certainly be fair to say that there is still much to be learnt in the area of NO biology. Here, a collection of papers by the many of the most active research groups in the field has been brought together. Some have contributed original research, others have written reviews to enable readers to get a up-to-date view of specialist areas in the field, while others still have written opinion articles, which give their views of the state-of-play in NO research as they see it.