Genome-wide analysis of the MATE gene family and expression analysis of subfamily III genes in response to aluminium toxicity in pineapple

Abstract

ABSTRACT Pineapple has strong adaptability to acidic soil and has become a significant economic fruit crop in the tropics and subtropics. The multidrug and toxin compound extrusion (MATE) gene family plays crucial roles in plant growth, development and responses to adverse stresses, especially in acidic soils. In this study, forty-two AcMATE genes were identified and classified into six subfamilies based on phylogenetic analysis. The chromosomal distribution, physical characteristics, phylogenetic relationships, and gene and protein structures of pineapple MATE gene family members were systematically analysed. Our results showed that six AcMATE genes can be further clustered into subfamily III with similar conserved motifs and exon-intron patterns, and are unevenly distributed on four pineapple chromosomes. Citrate exuding motif (CEM) was present in all six AcMATE proteins of subfamily III. Finally, quantitative real-time PCR experiments indicated that subfamily III AcMATE genes were highly expressed in roots and distinctly upregulated under Al stresses. In conclusion, our study illustrated that the AcMATE genes of subfamily III may function as an Al-induced citrate transporter in alleviating Al toxicity to adapt acidic soil in pineapple.