Genomic Identification and Expression Analysis of Acid Invertase (AINV) Gene Family in Dendrobium officinale Kimura et Migo

Abstract

Abstract Background Dendrobium officinale Kimura et Migo, a traditional Chinese orchid herb famous for its great horticultural and medicinal value, grows in an adverse habitat and suffers from abiotic or biotic stresses. Acid invertases (AINVs) are widely considered enzymes involved in regulating sucrose metabolism and here revealed to participate in responses to environmental stress in plants. The AINV gene family members have been identified and characterized in multiple plant genomes. However, detailed information about this gene family and their expression patterns are unknown in D. officinale despite their significance in polysaccharide biosynthesis. Results This study systematically analyzed the D. officinale genome and identified four DoAINV genes, classified into two subfamilies based on subcellular prediction and phylogenetic analysis. Comparison of gene structures and conserved motifs in DoAINV genes showed high conservation during their evolution. The conserved amino acids and domains of DoAINV proteins were characterized as pivotal for their function. Abiotic and biotic stress responses cis-elements were the most abundant motif in all DoAIVN genes, indicating they were stress-responsive. Furthermore, bioinformatics analysis of transcriptome data, validated by quantitative real-time reverse transcription PCR (qRT-PCR), revealed distinct organ-specific expression patterns of DoAINV genes in eight tissues and in response to abiotic stresses. Soluble sugar content and interaction network were examined to provide information on stress release and sucrose metabolism. Conclusions DoAINV genes are involved in various activities such as growth and development, stress response, and polysaccharide biosynthesis. The results provide valuable insights into the AINV family and will be helpful in further investigating DoAINV functions in D. officinale.