CC-NBS-LRR and LEA gene expression and morphological analysis supports adaptations of according to ploidy level in Agave accessions

Polyploidy in many Agave species have been widely described but still is unknown its influence on environmental response to the stress. Current study analyzed 16 morphological trials on five Agave accessions comprising three species (A. tequilana, A. angustifolia and A. fourcroydes) with different ploidy (2X, 3X, 5X and 6X) levels. It was possible to associate some morphological (spine, nuclei and stomata) traits to the ploidy level. Genetic analysis includes the characterization of two important stress-related genes, NBS-LRR and LEA genes induced by pathogenic infection, and heat or saline stresses, respectively. Amino acidic analysis in these genes showed more substitutions in those Agave accessions with higher ploidy level as A. fourcroydes var. Sac ki (5X) and A. angustifolia var. Chelem ki (6X). These last accessions also had a high LEA and NBS-LRR representativeness when are compared to its diploid and triploids counterparts. LEA and NBS-LRR gene expression were induces by saline or heat stresses, or by Erwinia carotovorum infection in all Agave accessions, and these transcriptional activation was also higher in A. angustifolia var Chelem ki (6X), and A. fourcroydes var. Sac ki (5X) than its diploid and triploids counterparts which suggests its mayor stress adaptation. Finally, the diploid accession A. tequilana var. Azul showed a differential genetic profile with regarding to other Agave accessions. These differences covering its genetic representativeness and its transcript accumulation, which were similar or higher than polyploidy (5X and 6X) Agave accessions, thus suggests a differential pressure selection, that overcome its lower ploidy level, in this Agave diploid specie.