The six pea varieties also demonstrated negative correlations between fluorescence signal and root length under both stressful and stress-mitigating conditions (Fig. ). In the case of Vicia faba L under saline stress, a strong negative correlation (y = -2.48x + 3.46, R 2 = -0.973) was observed between the fluorescence signal (y) and root length (x) across three different cultivation environments: natural water, NaCl-induced stress, and co-cultivation with NaCl+B. subtilis (Fig. , Table ). The results clearly showed that the fluorescence signals were crucial for accurately measuring ROS level across different pea varieties under various stressful conditions. The demonstrated effectiveness of AIEgens paves the way for creating highly sensitive and dependable fluorescence-based assays for investigating oxidative stress in plants. Moreover, this assessment offered valuable insights into selecting the most resilient pea variety for cultivation under stressful conditions and identifying the optimal planting conditions for various pea varieties, especially new varieties.