Abstract:

We investigated the ultraweak luminescence(UWL) emitted from the root of Platycladus orientalis and Acacia auriculiformis in responsing to soil drying and in a previous cycle of soil dehydration-rehydration to modify the UWL ability of root. Plants were grown in pots and subjected by rapid and slow soil drying. UWL is related to the soil drought time extend, soil water content (SWC) and root water content (RWC) reducing, P <0.001. But the relationship between UWL and leaf water potential (Ψ) is remarkable at the level of P <0.1. UWL recovers from the soil rehydration but its recovery rate is slower than SWC or Ψ. Results are discussed in the context of the sensibility of UWL to soil drought. We concluded that root UWL as an indicator of plant drought resistance is more sensitive than Ψ.

Key words: Platycladus orientalis, Acacia auriculiformis, Ultraweak luminescence, Signal delivery, Soil drying