Comprehensive Analysis of the Aquaporin Genes in Eucalyptus grandis Suggests Potential Targets for Drought Stress Tolerance

Abstract

This study delves into the comprehensive analysis of AQP genes in Eucalyptus grandis, providing insights into their genomic abundance, diversification, expression patterns across tissues, and responses to drought stress. We identified 48 AQP genes in the Eucalyptus grandis genome, categorized into four subfamilies: AQP-NIP, AQP-SIP, AQP-PIP, and AQP-TIP. This abundance of AQP genes is a reflection of gene duplications, both tandem and whole-genome, which have shaped their expansion. The chromosomal distribution of these genes reveals their widespread presence across the genome, with some subfamilies exhibiting more tandem duplications, suggesting distinct roles and evolutionary pressures. Sequence analysis uncovered characteristic motifs specific to different AQP subfamilies, demonstrating the diversification of protein and targeting. The expression profiles of AQP genes in various tissues in both Arabidopsis thaliana and Eucalyptus grandis showcased variations, with root tissues showing higher expression levels. Notably, AQP-PIP genes consistently exhibited robust expression across tissues, highlighting their importance in maintaining water regulation within plants. Furthermore, the study investigated the response of AQP genes to drought stress and rehydration, revealing differential expression patterns. EgAQP-NIP and EgAQP-TIP genes were up-regulated during drought stress, emphasizing their role in osmotic equilibrium and water transport. Conversely, EgAQP-PIP genes showed down-regulation during drought stress but were up-regulated upon rehydration, indicating their involvement in water movement across cell membranes. Overall, this research contributes to our understanding of AQP genes in Eucalyptus grandis, shedding light on their genomic evolution, expression patterns, and responses to environmental challenges, particularly drought stress. This information can be valuable for future studies aimed at enhancing the drought resilience of woody perennial plants like Eucalyptus grandis.