Abstract
The T-DNA insertion line in NMNAT (nicotinate/nicotinamide mononucleotide adenyltransferase) gene was found to produce less seeds. This allele only inherits maternally leading to male gametophytic malfunction. Hence, this allele was named MALE GAMETOPHYTIC MALFUNCTION (MGM). The rate of living pollen grains derived from mgm anthers was similar to wild type anthers. However, mgm affects pollen lifespan after release from anthers. Namely, a half-life of pollen from wild type and mgm were 85 hours and 40 hours, respectively. In vitro test revealed that only 40% of mgm pollen showed full tube growth after 16 hours. Furthermore, less pollen tube reached the micropyles when mgm or wild type stigma was pollinated with mgm pollen, resulted in decreased relative fertility than wild type pollen. Our results indicate that NAD is essential for the pollen tube growth, which eventually essential prerequisite for seed production.
