Garlic (Allium sativum L.) Invertase Genes: Genome-Wide Identification and Expression in Response to Abiotic Stresses and Phytohormones

Invertases are involved in plant growth, development, and stress adaptation; however, invertase-encoding genes have not yet been reported in Allium species. In this study, we identified 23 invertase izogenes in garlic (Allium sativum L.): 11 encoding putative neutral/alkaline (AsN/AINV1-11) and 12 acid (6 cell-wall-AsCWINV1-6 and 6 vacuolar-AsVINV1-6) enzymes. Among them, AsN/AINV1, 3, 8-10, AsCWINV2-5, and AsVINV2-6 showed significant transcription in garlic organs (roots, bulbs, pseudostems, leaves, sprouts, and reproductive parts) in a tissue-specific manner, whereas the AsN/AINV4-6, 11, AsCWINV1, 6, and AsVINV1 genes had weak or no detectable expression. Gene promoters contained nine, nine, and sixteen hormone-, stress-, and light-responsive cis-regulatory elements, respectively, and fifteen sites related to transcription factor binding and plant development. Expression analysis revealed that 12 invertase genes strongly transcribed in the roots of A. sativum cv. Ershuizao showed differential expression in the roots and leaves of A. sativum cv. Sarmat exposed to abiotic stresses (low temperature, high salinity, and drought) and phytohormones (abscisic acid and methyl jasmonate), which was significantly correlated with glucose, fructose, and sucrose contents. Our results should further functional analysis of invertases from Allium crops and contribute to the breeding of stress-tolerant varieties.