Microsporogenesis and the biosynthesis of floral small interfering RNAs in coffee have a unique pattern among eudicots, suggesting a sensitivity to climate changes
Kellen Kauanne Pimenta deOliveira,
Raphael Ricon deOliveira,
Gabriel deCampos Rume,
Thales Henrique Cherubino Ribeiro,
Christiane Noronha Fernandes‐Brum,
Laurence Rodrigues doAmaral,
Atul Kakrana,
Sandra Mathioni,
Blake C. Meyers,
Matheus deSouza Gomes,
Antonio Chalfun‐Junior
Affiliations
Kellen Kauanne Pimenta deOliveira
Laboratory of Plant Molecular Physiology, Plant Physiology Sector Institute of Biology, Federal University of Lavras (UFLA) Lavras Minas Gerais Brazil
Raphael Ricon deOliveira
Laboratory of Plant Molecular Physiology, Plant Physiology Sector Institute of Biology, Federal University of Lavras (UFLA) Lavras Minas Gerais Brazil
Gabriel deCampos Rume
Laboratory of Plant Molecular Physiology, Plant Physiology Sector Institute of Biology, Federal University of Lavras (UFLA) Lavras Minas Gerais Brazil
Thales Henrique Cherubino Ribeiro
Laboratory of Plant Molecular Physiology, Plant Physiology Sector Institute of Biology, Federal University of Lavras (UFLA) Lavras Minas Gerais Brazil
Christiane Noronha Fernandes‐Brum
Laboratory of Plant Molecular Physiology, Plant Physiology Sector Institute of Biology, Federal University of Lavras (UFLA) Lavras Minas Gerais Brazil
Laurence Rodrigues doAmaral
Laboratory of Bioinformatics and Molecular Analysis Federal University of Uberlândia (UFU) Campus Patos de Minas Patos de Minas Minas Gerais Brazil
Atul Kakrana
Donald Danforth Plant Science Center St. Louis MO USA
Sandra Mathioni
Donald Danforth Plant Science Center St. Louis MO USA
Blake C. Meyers
Donald Danforth Plant Science Center St. Louis MO USA
Matheus deSouza Gomes
Laboratory of Bioinformatics and Molecular Analysis Federal University of Uberlândia (UFU) Campus Patos de Minas Patos de Minas Minas Gerais Brazil
Antonio Chalfun‐Junior
Laboratory of Plant Molecular Physiology, Plant Physiology Sector Institute of Biology, Federal University of Lavras (UFLA) Lavras Minas Gerais Brazil
Abstract Recently, the siRNAs pathways, and especially reproductive phasiRNAs, have attracted attention in eudicots since their biological roles are still unknown and their biogenesis took different evolutionary pathways compared to monocots. In this work, we used Coffea arabica L., a recent allotetraploid formed from the hybridization of Coffea canephora and C. eugenioides unreduced gametes, to explore microsporogenesis and small RNAs‐related pathways in a eudicot crop. First, we identified the microsporogenesis stages during anther development revealing that pre‐meiosis occurs in anthers of 1.5 mm inside floral buds (FBs), whereas meiosis between 1.5 and 4.2 mm FBs, and post‐meiosis in FBs larger than 4.2 mm. These stages coincide with the Brazilian winter, a period of FBs reduced growth which suggests temperature sensitivity. Next, we identified and quantified the expression of reproductive 21‐ and 24‐nt phasiRNAs during coffee anther development together with their canonical and novel miRNA triggers, and characterized the DCL and AGO families. Our results showed that the pattern of reproductive phasiRNA abundance in C. arabica is unique among described eudicots and the canonical trigger car‐miR2275 is involved in the processing of both 21‐ and 24‐nt phasiRNAs. Fourteen DCL genes were identified, but DCL5, related to phasiRNA biosynthesis in monocots, was not, according to its specificity for monocots. Thus, our work explored the knowledge gap about microsporogenesis and related siRNAs pathways in coffee, contributing to the control of reproductive development and the improvement of fertility in eudicots.
