Biology subjects

Liou, P.-C.

Publications and source records attributed to Liou, P.-C..

3 recordsLinked to original sources

bioRxiv2024

Living xylem cells encode a large number of conserved gene families responsible for vascular sap peptides

Plant long-distance signaling peptides travel through the vascular system to coordinate development and respond to environmental cues, yet their precursor genes and expression origins remain elusive. We characterized 4,804 sap peptide precursor genes in Populus trichocarpa using an integrated approach that combined liquid chromatography tandem mass spectrometry (LC-MS/MS) peptidomics, transcriptomics, and comparative genomics. This study expands the known precursor families from approximately 50 to thousands, the majority of which are conserved across angiosperms. Transcriptome analysis across xylem developmental stages revealed that living xylem cells, typically viewed as precursors to non-living structures, predominantly express these specifically at transitions between primary and secondary growth stages, indicating an active role in plant-wide signaling coordination. The precursor genes show conservation at the transcriptome level and are under strong purifying selection. Our findings provide a comprehensive overview of the gene families encoding sap peptides, redefining xylem as an active participant in plant communication and adaptation.

plant biology↗

bioRxiv2024

Evolutionary conserved sap peptides derived from xylem-specific peptide precursors in woody angiosperms

Peptides act as long-distance mobile signals, transported through vascular sap to coordinate complex developmental processes. Since the tissue-specificity of peptide precursor gene expression is critical in determining peptide signaling function, we integrated vascular sap peptidomes with tissue-level transcriptomes to investigate the roles of sap peptides in two economically important woody plants, Populus trichocarpa and Eucalyptus grandis. Xylem exhibited the highest ratio of tissue-specific sap peptide precursor genes. Most of the sap peptides derived from xylem-specific precursor genes of P. trichocarpa and E. grandis were highly conserved throughout woody species selected from different clades in angiosperms, including magnoliids, rosids and asterids in eudicots. To further explore the conservation of these peptides, we examined the sap peptidome of Cinnamomum kanehirae (camphor tree), from the ancient clade with three xylem cell types. Approximately 90% of the peptides from xylem-specific precursors that were conserved between P. trichocarpa and E. grandis, were also conserved in the vascular sap of C. kanehirae, demonstrating a remarkably high conservation of these peptides across woody angiosperms. Most of the sap peptides conserved in these three woody species are also highly conserved across land plants, suggesting that these peptides may contribute to plant terrestrialization. Within the sap peptides from xylem- specific precursor genes, a total of 10 peptides were identical across all three woody plants. This substantial enrichment of xylem-specific precursor-derived peptides, along with their high conservation, suggests that these long-distance mobile peptides play a crucial role in secondary xylem development. One sentence summaryIntegration of sap peptidomic and tissue-level transcriptomic data revealed highly conserved long-distance mobile peptides derived from xylem- specific precursors across woody angiosperms.

evolutionary biology↗

bioRxiv2024

A Sap Peptide Conserved across Flowering Plants Positively Regulates Lignin Biosynthesis, Biomass and Immunity

Signaling peptides act as hormones to deliver short- or long-distance intercellular signals to govern complex developmental processes. Identifying endogenous signaling peptides is challenging due to their low abundance and the unknown cleavage sites required for release from precursor proteins, not to mention the investigation of their evolutionary roles across species. Consequently, very few peptides were evolutionarily characterized in vivo, especially long-distance signaling peptides. Here we present current largest peptidomic datasets from six species (maize, camphor tree, tomato, rose gum, soybean and poplar), totaling 12,242 peptides, selected from all representative evolutionary clades of angiosperms, including monocots, magnoliids, rosid eudicots, and asterid eudicots. A sap peptide was found to be identical across all six species and named as ASAP (angiosperm sap peptide), emerging as the most conserved peptide family discovered thus far. ASAP rapidly induces a series of protein phosphorylation involved in a signaling cascade previously reported to regulate lignin biosynthesis, plant growth and plant immunity. Functional assays on ASAP activity demonstrated its capability on the induction of monolignol biosynthesis and lignin deposition. High-throughput phenomic analyses showed that ASAP significantly increased plant above- and below-ground biomass. In addition, ASAP treatment enhanced plant immunity and reduced the number of galls and egg masses against nematode invasion. This study provides insights into the conservation and functional significance of plant long-distance mobile signaling peptides, offering potential applications in crop improvement and disease management strategies.

plant biology↗