Final Report Summary - SYMDEV (The role of symplastic communication during root development) In the ERC funded project “The role of symplastic communication during root development” (SYMDEV) we addressed four parallel objectives. (1) We identified a new cellular pathway that unloads carbon through phloem tissue to the root meristem through the phloem sieve element, pericycle cells and ground tissue. We also identified the critical role for the sphingolipids in specifying the rate of unloading. (2) We identified a set of novel regulators, such as transcription factors (NAC45/86) and nuclease enzymes (NEN1-4) determining phloem morphogenesis. (3) By taking advantage of the newly developed molecular tool with which we can block symplastic trafficking through the plasmodesmata, we uncovered a new class of mobile transcription factors (PEAR), the corresponding genes of which are transcribed in undifferentiated sieve element cells and who move to the neighboring cells to guide their gene expression and cell behavior. (4) The knowledge from (1-3) is helping to develop a general framework for understanding and engineering carbon allocation processes related to agriculture and forestry.
