The Role of INAPERTURATE POLLEN1 as a Pollen Aperture Factor Is Conserved in the Basal Eudicot Eschscholzia californica (Papaveraceae) Mazuecos Aguilera, Ismael Romero García, Ana Teresa Fernández Fernández, Carmen Ben-Menni Schuler, Samira Suárez Santiago, Víctor Eschscholzia californica INAPERTURATE POLLEN1 Papaveraceae Pollen Pollen aperture RNA-Seq Transcriptome analysis VIGS This study was supported by the Spanish Ministry of Economy and Competitiveness (project CGL2015-70290-P to VS-S) and by the US National Science Foundation (MCB-1817835 to AD). IM-A was supported by a predoctoral grant (F.P.I. program) from the Spanish Government. BK was supported by the Ministry of Education, Youth and Sports of the Czech Republic (project LTC20050) and DH was supported by Czech Science Foundation (project 21-15856S). Pollen grains show an enormous variety of aperture systems. What genes are involved in the aperture formation pathway and how conserved this pathway is in angiosperms remains largely unknown. INAPERTURATE POLLEN1 (INP1) encodes a protein of unknown function, essential for aperture formation in Arabidopsis, rice and maize. Yet, because INP1 sequences are quite divergent, it is unclear if their function is conserved across angiosperms. Here, we conducted a functional study of the INP1 ortholog from the basal eudicot Eschscholzia californica (EcINP1) using expression analyses, virus-induced gene silencing, pollen germination assay, and transcriptomics. We found that EcINP1 expression peaks at the tetrad stage of pollen development, consistent with its role in aperture formation, which occurs at that stage, and showed, via gene silencing, that the role of INP1 as an important aperture factor extends to basal eudicots. Using germination assays, we demonstrated that, in Eschscholzia, apertures are dispensable for pollen germination. Our comparative transcriptome analysis of wildtype and silenced plants identified over 900 differentially expressed genes, many of them potential candidates for the aperture pathway. Our study substantiates the importance of INP1 homologs for aperture formation across angiosperms and opens up new avenues for functional studies of other aperture candidate genes. 2021-09-14T10:24:33Z 2021-09-14T10:24:33Z 2021-07-07 journal article Mazuecos-Aguilera I... [et al.] (2021) The Role of INAPERTURATE POLLEN1 as a Pollen Aperture Factor Is Conserved in the Basal Eudicot Eschscholzia californica (Papaveraceae). Front. Plant Sci. 12:701286. doi: [10.3389/fpls.2021.701286] http://hdl.handle.net/10481/70203 10.3389/fpls.2021.701286 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Frontiers Research Foundation