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Abstract In plants, the cell wall fixes the position of each cell; therefore, during development, plants rely on cellular proliferation and expansion for tissue patterning and organ formation. How plant cells communicate with neighboring cells to coordinate expansion for properly patterned tissues and organs is not well understood. In seed plants, organ growth is known to be modulated by sulfotyrosyl peptide signaling. Here, we report that the activity of TYROSYL PROTEIN SULFOTRANSFERASE (TPST), which is responsible for the post-translational modification of sulfotyrosyl peptides, is essential for expansion during development in the non-vascular plant,Physcomitrium patens. Plants that harbor a null mutation in the gene encoding TPST (Δtpst) were smaller, formed fewer caulonemal filaments, and were unable to form expanded gametophores. In Δtpstmultiple aspects of gametophore development were affected, including the first division of the gametophore initial, as well as reduced rates of cell division and expansion. Mutational analysis ofP. patensTPST identified the residue Histidine 124, a candidate catalytic residue, as essential for TPST function. Notably, addition of the sulfated signaling peptide, PSY1 from eitherP. patensorArabidopsis thaliana, rescued all Δtpstdevelopmental deficits. Taken together, these data suggest that TPST functions to sulfate PSY, and this activity is necessary for plant growth and development. Furthermore, since addition of AtPSY fully rescues Δtpstand PpPSY promotes root elongation in Arabidopsis and rice, these findings suggest that PSY signaling is evolutionarily conserved.
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Molecular mechanisms of tubulogenesis revealed in the sea star hydro-vascular organ
Abstract A fundamental goal in the organogenesis field is to understand how cells organize into tubular shapes. Toward this aim, we have established the hydro-vascular organ in the sea starPatiria miniataas a model for tubulogenesis. In this animal, bilateral tubes grow out from the tip of the developing gut, and precisely extend to specific sites in the larva. This growth involves cell migration coupled with mitosis in distinct zones. Cell proliferation requires FGF signaling, whereas the three-dimensional orientation of the organ depends on Wnt signaling. Specification and maintenance of tube cell fate requires Delta/Notch signaling. Moreover, we identify target genes of the FGF pathway that contribute to tube morphology, revealing molecular mechanisms for tube outgrowth. Finally, we report that FGF activates the Six1/2 transcription factor, which serves as an evolutionarily ancient regulator of branching morphogenesis. This study uncovers distinct mechanisms of tubulogenesis in vivo and we propose that cellular dynamics in the sea star hydro-vascular organ represents a key comparison for understanding the evolution of vertebrate organs.
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- Award ID(s):
- 1923445
- PAR ID:
- 10542300
- Publisher / Repository:
- Nature
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 14
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1038/s41467-023-37947-2
