Plants are exposed to various environmental stresses such as drought, cold, and high salinity during their sessile lifetime. The Late-Embryogenesis Abundant (LEA) proteins are involved in protection against different environmental stresses. LEA proteins have been classified into 7 groups based on sequence similarity and conserved domains. Among these groups, the functions of only group 1, 2 and 3 genes in regulating abiotic stress tolerance have been investigated. The productivity of watermelon (Citrullus lanatus), the most economically important cucurbitaceous crop, is affected by environmental stresses, but the functions of environmental stress-related genes in watermelon have not been reported yet. Therefore, abiotic and biotic stress-related research on watermelon is necessary. In this study, we selected Cl017745 (ClLEA3-1) as a representative group 3 LEA protein based on the watermelon database (http://www.icugi.org) and reported its expression patterns in response to diverse stresses and ABA treatment. Tissue-specific expression pattern of ClLEA3-1 was induced by dehydration, low-temperature, high-salinity, and abscisic acid (ABA) treatment, but expression of ClLEA3-1 was not increased by inoculation with a pathogen. Subcellular localization analysis showed that ClLEA3-1 was a cytosolic protein. Therefore, we recommend that ClLEA3-1 (Cl017745) can be used as an abiotic stress marker gene in watermelon.
