Long-Distance Signaling via Mobile RNAs
Beyond its role in moving sugars from source leaves to sinks, the phloem is an important conduit for transporting information molecules that function as signals responding to environmental and internal cues related to numerous aspects of physiology. One of the most prominent groups of these signaling molecules is full-length mRNAs. Thousands of full-length transcripts have been identified in sieve elements of the phloem, but only a few have been confirmed to be mobile. This chapter focuses on six RNAs that move long distance through the plant and have a documented role in regulating development. These include StBEL5 and POTH1 of potato, CmGAI of pumpkin, PFP-LeT6 from tomato, and Aux/IAA and FLOWERING LOCUS T from Arabidopsis. Their impact in controlling development and the mechanisms that facilitate their movement are discussed.
KeywordsNon-cell-autonomous Phloem Polypyrimidine tract-binding proteins Potato Signal Vascular biology
Thanks to Anjan Banerjee, Yiguo Hong, and Tien-Shin Yu for allowing use of their data for this book chapter. Thanks also to Anjan Banerjee, Mithu Chatterjee, Ameya Mahajan, and Xin Meng for their dedicated contributions to this work.