Abstract: As a regulator of various stress responses, protein BLI promotes the adaptability of plants to the environment and maintains the normal growth of plants by inhibiting protein IRE1. Arabidopsis thaliana individuals without protein BLI are shown to have the mutant phenotype of pleiotropic development. The senescence-related characteristics of BLI mutant Arabidopsis thaliana plants were studied with the cell biology and genetic methods. It was found that a series of senescence phenotypes, such as leaf yellowing, decreased chlorophyll content and increased cell conductivity, appeared in the early stage of the BLI mutant plants and, at the same time, the expression of senescence-related genes in BLI mutant plants was up-regulated and the expression of photosynthesis-related genes was down-regulated. These results preliminarily proved that protein BLI was involved in plant senescence. Applying exogenous ROS to wild-type Col-0 plants showed that the BLI expression was reduced and GUS staining showed that BLI was expressed in all parts of the plant, which provides clues for further analyzing the molecular network for BLI regulating senescence.