Sphingolipid biosynthesis modulates plasmodesmal ultrastructure and phloem unloading
Abstract
During phloem unloading, multiple cell-to-cell transport events move organic substances to the root meristem. Although the primary unloading event from the sieve elements to the phloem pole pericycle has been characterized to some extent, little is known about post-sieve element unloading. Here, we report a novel gene, PHLOEM UNLOADING MODULATOR (PLM), in the absence of which plasmodesmata-mediated symplastic transport through the phloem pole pericycle--endodermis interface is specifically enhanced. Increased unloading is attributable to a defect in the formation of the endoplasmic reticulum--plasma membrane tethers during plasmodesmal morphogenesis, resulting in the majority of pores lacking a visible cytoplasmic sleeve. PLM encodes a putative enzyme required for the biosynthesis of sphingolipids with very-long-chain fatty acid. Taken together, our results indicate that post-sieve element unloading involves sphingolipid metabolism, which affects plasmodesmal ultrastructure. They also raise the question of how and why plasmodesmata with no cytoplasmic sleeve facilitate molecular trafficking.
Cite
@article{arxiv.1912.03949,
title = {Sphingolipid biosynthesis modulates plasmodesmal ultrastructure and phloem unloading},
author = {Dawei Yan and Shri Yadav and Andrea Paterlini and William Nicolas and Ilya Belevich and Magali Grison and Anne Vaten and Leila Karami and Sedeer El-Showk and Jung-Youn Lee and Gosia Murawska and Jenny Mortimer and Michael Knoblauch and Eija Jokitalo and Jonathan Markham and Emmanuelle Bayer and Ykä Helariutta},
journal= {arXiv preprint arXiv:1912.03949},
year = {2019}
}
Comments
Nature Plants, Nature Publishing Group, In press