Skip to main content
padlock icon - secure page this page is secure

Free Content Nicotinamidase activity is important for germination

Download Article:

You have access to the full text article on a website external to Ingenta Connect.

Please click here to view this article on Wiley Online Library.

You may be required to register and activate access on Wiley Online Library before you can obtain the full text. If you have any queries please visit Wiley Online Library


It has been suggested that nicotinamide must be degraded during germination; however, the enzyme responsible and its physiological role have not been previously studied. We have identified an Arabidopsis gene, NIC2, that is expressed at relatively high levels in mature seed, and encodes a nicotinamidase enzyme with homology to yeast and bacterial nicotinamidases. Seed of a knockout mutant, nic2-1, had reduced nicotinamidase activity, retarded germination and impaired germination potential. nic2-1 germination was restored by after-ripening or moist chilling, but remained hypersensitive to application of nicotinamide or ABA. Nicotinamide is a known inhibitor of NAD-degrading poly(ADP-ribose) polymerases (PARP enzymes) that are implicated in DNA repair. We found reduced poly(ADP)ribosylation levels in nic2-1 seed, which were restored by moist chilling. Furthermore, nic2-1 seed had elevated levels of NAD, and germination was hypersensitive to methyl methanesulphonate (MMS), suggesting that PARP activity and DNA repair responses were impaired. We suggest that nicotinamide is normally metabolized by NIC2 during moist chilling or after-ripening, which relieves inhibition of PARP activity and allows DNA repair to occur prior to germination.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Arabidopsis; NAD; germination; nicotinamide; poly(ADP-ribose) polymerase; sirtuin

Document Type: Research Article

Affiliations: 1: Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK, and 2: Division of Agriculture and Environmental Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, LE12 5RD, UK

Publication date: August 1, 2007

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more