Key Genes Involved in the Saline–Water Stress Tolerance of Aloe vera

<i>Aloe vera</i> is well known for its high tolerance to adverse environmental conditions. However, the molecular pathways governing its adaptive response mechanisms to abiotic stress remain unclear. Thus, the expression of <i>AOG</i>, <i>ABA2</i>, and <i>GMMT</i> genes in <i>Aloe vera</i> plants subjected to saline-water stress was evaluated, with the expression of key genes significantly influenced by stress response. <i>AOG</i> and <i>GMMT</i> expression levels were higher under field capacity (FC) than under water deficit (PWP), with <i>AOG</i> reaching ~4.3% under 40 mM salinity at FC. In contrast, <i>ABA2</i> was strongly upregulated under PWP, particularly at 40 mM salinity, with expression increasing up to fivefold compared to the control. However, salinity above 40 mM led to reduced <i>ABA2</i> expression. <i>GMMT</i> was overexpressed (~6%) under severe stress, while mannose content increased significantly with salinity but remained unaffected by soil moisture. These findings highlight gene-specific responses to combined stress.