Genome-wide identification, characterization, and expression analysis of aluminum-activated malate transporter genes (ALMTs) in Gossypium hirsutum L.

Aluminum-activated malate transporters (ALMT) are widely involved in plant growth and metabolic processes, including adaptation to acid soils, guard cell regulation, anion homeostasis, and seed development. Although ALMT genes have been identified in Arabidopsis, wheat, barley, and Lotus japonicus, little is known about its presence in Gossypium hirsutum L. In this study, ALMT gene recognition in diploid and tetraploid cotton were done using bioinformatics analysis that examined correlation between homology and evolution. Differentially regulated ALMT genetic profile in G. hirsutum was examined, using RNA sequencing and qRT-PCR, during six fiber developmental time-points, namely 5 d, 7 d, 10 d, 15 d, 20 d, and 25 d. We detected 36 ALMT genes in G. hirsutum, which were subsequently annotated and divided into seven sub-categories. Among these ALMT genes, 34 had uneven distribution across 14/26 chromosomes. Conserved domains and gene structure analysis indicated that ALMT genes were highly conserved and composed of exons and introns. The GhALMT gene expression profile at different DPA (days post anthesis) in different varieties of G. hirsutum is indicative of a crucial role of ALMT genes in fiber development in G. hirsutum. This study provides basis for advancements in the cloning and functional enhancements of ALMT genes in enhancing fiber development and augmenting high quality crop production.