Studies on the role of the<i>SlNAC3</i>gene in regulating seed development in tomato (<i>Solanum lycopersicum</i>)

Abstract

SummaryPlant seeds contain the sporophytic embryo and nutrients for embryo development. To ensure correct seed formation, co-ordination between the embryo, the endosperm, and the maternal seed components must be achieved. However, this regulatory mechanism is poorly understood. Here, we demonstrate that an NAC gene (SlNAC3) was essential for young embryo and endosperm development in tomato (Solanum lycopersicum). Transgenic tomato seeds expressing SlNAC3 RNA interference (RNAi) exhibited defects in pollen viability and a reduced seed size. Ultrastructural analysis revealed the absence of an embryo sac, while the endosperm collapsed in the seed of transgenic tomato plants expressing lower levels of SlNAC3 transcripts due to RNAi. Real-time quantitative RT-PCR analysis revealed the down-regulation (to < 10% of wild-type levels) of four genes involved in jasmonic acid (JA) biosynthesis in the flowers of transgenic plants. These results demonstrate that the SlNAC3 gene plays a critical role in the development of the embryo in tomato seed.