Noninvasive and Real-time Monitoring of the Regulation of Plant Growth and Development Using Delayed Fluorescence Technique

The structure and function of photosynthetic apparatus in plant leaves can be affected by plant growth regulators (PGRs) and other exogenous chemical factors. The photosystem II in a plant is considered the primary site where light-induced delayed fluorescence (DF) is produced. With the lamina of soybean (Glycine max (L.) Merr.) seedlings as testing models, we have studied the effects of sodium bisulfite (NaHSO₃) on characteristics of DF using a home-made portable DF detection system. The results show that the changes in DF intensity can reflect the changes in photosynthetic capacity caused by NaHSO₃. Therefore, the light-induced DF is a novel and excellent marker for early and rapidly detecting the regulatory effects of NaHSO₃ on plant photosynthetic metabolism. DF technique could be potential useful for real-time monitoring the effects of PGRs and other exogenous chemical factors on plant growth and development.