About this Research Topic
In this Research Topic we want to set the stage for significant advances in all aspects of phytolith research. Phytoliths are deposits of amorphous silica in higher plants. Deposition takes place in a variety of organs, from roots and stems, to leaves and inflorescences, and in a variety of biochemical environments within the cells of these organs, including cell walls and the cell lumen. The deposition of silica in phytoliths is significant in providing structural integrity for some plant species and may also be involved in the regulation of transpiration. Silica makes plant material less palatable, and is therefore important in defences against grazers and pathogens. Understanding of the uptake of silica from the soil and its transport through the plant has markedly increased in the last ten years, but we still have a relatively poor understanding of the processes affecting silica deposition in plant cells, and how this impacts phytolith composition, solubility, and longevity.
Phytolith analysis is now a popular technique in palaeoecological and archaeological investigations. Phytoliths can tell us much about past environments and agriculture, what animals and people ate and more. Considerable progress has been made on phytolith taxonomy with the development of the International Code for Phytolith Nomenclature 1.0 (version 2.0 is in progress). A combination of image analysis techniques and statistics has enabled plant species identification in some cases from only a few phytoliths. Studies on the chemical and isotopic composition of phytoliths, and how this is determined by the deposition environment, could potentially provide additional information on the environmental context and Si cycling.
This brings us to the role of phytoliths in the terrestrial biogeochemical cycles of silicon and carbon. In both natural and agricultural contexts, phytoliths are a key source of soluble silicon in the soil, much more so than aluminosilicates. Rice husks, which are rich in deposited silica in the form of phytoliths, are often used as a fertilizer in rice paddies. Continuous harvesting of cereal shoot material and not returning it to the land may decrease the amount of soluble silicon available for plant uptake with possible deleterious effects on plant growth. Carbon sequestration in phytoliths has become an important research topic in the last few years. There is still some controversy over the amount of carbon that is sequestered by phytoliths in soil, but there is ample reason to believe that this could be significant, and that it may have an important role in combatting global warming.
Frontiers in Phytolith Research will consider all aspects of phytolith research, from the molecular mechanisms of phytolith formation in the plant to their importance in terrestrial biogeochemical silicon cycle and carbon sequestration. The aim will be to draw together top quality research from across the complete range of phytolith studies, and to take advantage of cross-listing by involving a number of Frontiers journals. We will thereby assemble a collection of papers that will showcase the very best of phytolith research, and foster interdisciplinary thinking.
Keywords: Phytolith, Silica, Silicon, Plant
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.