Agave striata transcriptome reveals candidate cellulose synthase A genes involved in sisal cellulose biosynthesis

Agave striata is a typical ornamental agave species that can be used as a wild genotype to explore the domestication of agronomic traits in A. tequilana and A. H11648. Hence, we assembled the first A. striata transcriptome with 112,718 transcripts, which will be a useful bioinformatics database for the evolutionary patterns and gene functional characterization of agave species. The annotation results of these transcripts indicate their phylogenetic position in the Asparagaceae family. We further identified and cloned 19 cellulose synthase A (CesA) genes in A. deserti, A. tequilana, and A. H11648 according to their transcriptome databases. Interestingly, phylogenetic analysis revealed a species-specific expansion of CesA genes in the agave species. However, none of these were positively selected in the domesticated agave species A. tequilana and A. H11648. Their expression patterns revealed that the candidate functions of these two genes were significantly correlated with cellulose accumulation during leaf development and oomycete infection. The results revealed the candidate CesA genes for cellulose biosynthesis, which will serve as a guide for the genetic improvement of cellulose traits in agaves.