An efficient method for the collection of root mucilage from different plant species—A case study on the effect of mucilage on soil water repellency

Root mucilage may play a prominent role in understanding root water uptake and, thus, there is revived interest in studying the function of root mucilage. However, mucilage research is hampered by the tedious procedures of mucilage collection. We developed a mucilage separator which utilizes low centrifugal forces (570 rpm) to separate the mucilage from seminal roots without the need of handling individual seeds or removing the germinated seeds from the tray/mesh to a centrifuge tube. For the different plant species, between 1 and 3.7 mL tray^?1 of hydrated mucilage could be produced, with 6 trays being handled successively within 45 min. For Triticum aestivum, which showed a dry matter content of 0.5%, this was equivalent to 98.6 mg mucilage dry matter. The lowest total production was found for Zea mays with just 34 mg dry matter. The amounts of mucilage produced normalized to root tip agree well with literature data. The mucilage obtained by the new method was used to measure its effect on repellency of soil as this property directly relates to the phenomenon of lower rhizosphere soil water content during rewetting. It could be shown that repellency of the rhizosphere is affected by the quantity as well as by species‐dependent quality of mucilage in the rhizosphere. Among the species tested (Lupinus albus, Vicia faba, Zea mays, Triticum aestivum), the largest differences were observed between the two legumes. For Zea mays seminal root mucilage obtained with the new system was compared to mucilage of air born brace roots. The differences between these two mucilages, representing different root orders, indicate clearly that there is still a need for methods which enable the investigation of roots from older plants.