title: Multiple Mobile mRNA Signals Regulate Tuber Development in Potato.
abstract: Included among the many signals that traffic through the sieve element system are full-length mRNAs that function to respond to the environment and to regulate development. In potato, several mRNAs that encode transcription factors from the three-amino-loop-extension (TALE) superfamily move from leaves to roots and stolons via the phloem to control growth and signal the onset of tuber formation. This RNA transport is enhanced by short-day conditions and is facilitated by RNA-binding proteins from the polypyrimidine tract-binding family of proteins. Regulation of growth is mediated by three mobile mRNAs that arise from vasculature in the leaf. One mRNA,StBEL5, functions to activate growth, whereas two other, sequence-related StBEL's,StBEL11andStBEL29, function antagonistically to repress StBEL5 target genes involved in promoting tuber development. This dynamic system utilizes closely-linked phloem-mobile mRNAs to control growth in developing potato tubers. In creating a complex signaling pathway, potato has evolved a long-distance transport system that regulates underground organ development through closely-associated, full-length mRNAs that function as either activators or repressors.
authors.affiliation: Plant Biology Major, 253 Horticulture Hall, Iowa State University, Ames, IA 50011-1100, USA. djh@iastate.edu.
authors.forename: David J
authors.initials: DJ
authors.lastname: Hannapel
authors.affiliation: Biology Division, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411008, India. akb@iiserpune.ac.in.
authors.forename: Anjan K
authors.initials: AK
authors.lastname: Banerjee
keywords: Solanum tuberosum; StBEL; TALE; phloem; signals; tuberization