The N-terminal acetyltransferase Naa50 regulates tapetum degradation and pollen development in Arabidopsis. (March 2022) - Feng, Jinlin
Highlights: The lacking of Naa50 resulted in collapsed and sterile pollen caused from the sporophytic effects in Arabidopsis . Naa50 was specifically expressed in tapetum cells of anthers at 9–11 stages, and mutation in Naa50 accelerated the tapetum degradation. The loss of Naa50 resulted in the up-regulation of CEP1, which is necessary for the timely degeneration of tapetal cells. Abstract: The N-terminal acetylation of proteins is a key modification in eukaryotes. However, knowledge of the biological function of N-terminal acetylation modification of proteins in plants is limited. Naa50 is the catalytic subunit of the N-terminal acetyltransferase NatE complex. We previously demonstrated that the absence of Naa50 leads to sterility in Arabidopsis thaliana . In the present study, the lack of Naa50 resulted in collapsed and sterile pollen in Arabidopsis . Further experiments showed that the mutation in Naa50 accelerated programmed cell death in the tapetum. Expression pattern analysis revealed the specific expression of Naa50 in the tapetum cells of anthers at 9–11 stages during pollen development, when tapetal programmed cell death occurred. Reciprocal cross analyses indicated that male sterility in naa50 is caused by sporophytic effects. mRNA sequencing and quantitative PCR of the closed buds showed that the deletion of Naa50 resulted in the upregulation of the cysteine protease coding gene CEP1 and impaired the expression of several genes involved in pollen wall deposition and pollen mitotic division. The collective data suggest that Naa50 balances the degradation of tapetum cells during anther development and plays an important role in pollen development by affecting several pathways.