Cloning and molecular characterisation of a putative glyoxalase I Gene ( HfGlX I-1 ) of Daylily ( Hemerocallis spp.)

Excessive methylglyoxal (MG), which is produced by plants in response to biotic or abiotic stress, could be removed by the glyoxalase system. Glyoxalase I is the main component of the glyoxalase system, and it plays an important role in conferring abiotic stress tolerance of plants. In this study, glyoxalase I activity of different daylily ( Hemerocallis spp.) varieties was measured and compared, showing that glyoxalase I activity was positively correlated with salt tolerance in daylily. In addition, a putative glyoxalase I gene ( HfGlX I-1 ) of daylily was cloned and introduced to tobacco ( Nicotiana benthamiana ). Results showed that the glyoxalase I activity of transgenic plants was higher than that of wild-type plants, indicating that HfGlX I-1 served as glyoxalase I. Furthermore, transgenic tobacco showed tolerance to abiotic stress, including drought, high concentrations of sodium chloride and zinc chloride. Our results could establish the potential selection system of salt-tolerant daylily and provide a molecular tool to modify the biotic tolerance of ornamental plants.