A Deeper Understanding of Differential Sense/Antisense RNA Representation in Reproductive Organs of Sexual and Apomictic Paspalum Notatum

PODIO M; COLONO, C; SIENA L; ORTIZ JPA; PESSINO SC

Rosario

Workshop; 7th Series of Seminars on Advances in Apomixis Research; 2021

EU-funded Mechanisms of Apomictic Development

The selection of apomixis genes to be used as breeding/research tools requires detailed characterization of the expression landscape across multiple developmental stages. Our group established Roche 454/FLX+ reference floral transcriptomes from sexual and apomictic Paspalum notatum biotypes and used these solid frames to assist the assembly of 24 extensive TruSeq®/Hiseq Illumina libraries, covering in triplicate four reproductive steps (pre-meiosis, meiosis, post-meiosis, anthesis). Moreover, de novo assemblies were constructed with Trinity to complete an integrative global transcriptome. For differential expression analysis, RNA-seq reads were analyzed with the Kallisto v.0.44.0 software to determine transcript counts and abundances. These analysis allowed us to: (1) identify sequences differentially expressed in apomictic and sexual biotypes, which were consistently differential on the course of development or otherwise stage-specific; (2) characterize some differentially expressed transcript clusters (particularly transcription factors of the AP2, ARF, MYB, and WRKY groups, as well as hormone-pathways controllers of the auxin, jasmonate, and cytokinin families); (3) detect a number of antisense sequences differentially modulated between reproductive modes; and (4) gain knowledge on the expression of a group of transcripts that had been previously associated with apomixis. Currently, we are using the Illumina libraries to identify transcripts expressed from the apomixis controlling locus (ACL), whose sequence is partially available through the Paspalum genomesequencing initiative.