Biology subjects

Montes-Serey, C.

Publications and source records attributed to Montes-Serey, C..

3 recordsLinked to original sources

bioRxiv2023

Improved Super-Resolution Ribosome Profiling Revealed Prevalent Translation of Upstream ORFs and Small ORFs in Arabidopsis

A crucial step in functional genomics is identifying actively translated open reading frames (ORFs) that link biological functions. The challenge lies in identifying short ORFs, as they are greatly impacted by data quality and depth. Here, we improved the coverage of super-resolution Ribo-seq in Arabidopsis, revealing uncharacterized translation events in nucleus-, chloroplast-, and mitochondria-encoded genes. We identified 7,751 unconventional translation events, including 6,996 upstream ORFs (uORFs) and 209 downstream ORFs on annotated protein-coding genes, as well as 546 ncORFs on presumed non-coding RNAs. Proteomics data confirmed the production of stable proteins from some of the unannotated translation events. We present evidence of active translation on primary transcripts of tasiRNAs (TAS1-4) and microRNAs (pri-miR163, pri-miR169), and periodic ribosome stalling supporting co-translational decay. Additionally, we developed a method for identifying extremely short uORFs, including 370 minimum uORF (AUG-stop), and 2,984 tiny uORFs (2-10 aa), as well as 681 uORFs that overlap with each other. Remarkably, these short uORFs exhibit strong translational repression as longer uORFs. We also systematically discovered 594 uORFs regulated by alternative splicing, suggesting widespread isoform-specific translational control. Finally, these prevalent uORFs are associated with numerous important pathways. In summary, our improved Arabidopsis translational landscape provides valuable resources to study gene expression regulation.

genomics↗

bioRxiv2023

A soybean rust effector protease suppresses host immunity and cleaves a 3-deoxy-7-phosphoheptulonate synthase

The devastating soybean rust (SBR) pathogen, Phakopsora pachyrhizi, encodes many secreted proteins, but only two have been functionally characterized for their roles in rust virulence. Here, we demonstrate that transient expression of P. pachyrhizi effector candidate 15 (PpEC15), an aspartic protease, leads to enhanced bacterial growth in planta, suppression of callose deposition, reduced expression of plant defense-related marker genes and suppression of pathogen-associated molecular pattern (PAMP)-induced reactive oxygen species (ROS). Stable expression of PpEC15 in soybean suppresses PAMP-induced ROS production and enhances bacterial growth, indicating that, collectively, PpEC15 suppresses host and non-host innate immune responses. Yeast-two-hybrid and proximity labeling identified putative PpEC15 interacting partners including a peptide-chain release factor (PCRF), a NAC83 (NAM, ATAF, and CUC) transcription factor, and a DAHP (3-deoxy-7-phosphoheptulonate) synthase. We further show that PpEC15 can cleave DAHP but does not cleave PCRF or NAC83. Virus-induced gene silencing of NAC83, PCRF and DAHP altered PAMP-induced ROS production and salicylic acid production, indicating that these proteins may be involved in immune signaling. Collectively, our data show that PpEC15 is conserved across P. pachyrhizi isolates and other economically important rust species and is involved in the suppression of plant basal defense responses. Understanding the role of PpEC15 in P. pachyrhizi virulence will provide a foundation for designing targeted intervention strategies to generate rust-resistant crops.

plant biology↗

bioRxiv2022

Plasmodesmata-located proteins regulate plasmodesmal function at specific cell interfaces in Arabidopsis

Plasmodesmata (PD) are membrane-lined channels connecting adjoining plant cells. PD control symplasmic intercellular communication by allowing molecules to move between cells. Plant polysaccharide callose ({beta}-1,3-glucan) is deposited at PD, affecting plasmodesmal function; however, the regulation of PD at different cell interfaces is largely unknown. This study discovered that two PD-located proteins, PDLP5 and PDLP6, are expressed in non-overlapping cell types. The constitutive expression of PDLP5 and PDLP6 results in the overaccumulation of PD callose at different cell interfaces and starch hyperaccumulation in different cell types within mature leaves. Using a proximity labeling approach, we identified sucrose synthase 6 (SUS6) as a functional partner of PDLP6. We further demonstrated that PDLP6 physically and genetically interacts with SUS6. In addition, callose synthase 7 (CalS7) interacts with both SUS6 and PDLP6 and is required for PDLP6s function. We propose that PDLP6-SUS6-CalS7 forms a callose synthase complex in the vasculature to regulate the plasmodesmal function.

plant biology↗