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Biology subjects

Yang, S.-L.

Publications and source records attributed to Yang, S.-L..

5 recordsLinked to original sources

Endocytosis of the damage-associated molecular pattern receptor PEPR1 is BAK1-dependent.

After cellular damage caused by wounding or pathogens, Arabidopsis thaliana endogenous elicitor peptides (Peps) are released into the apoplast, enhancing innate immunity by directly binding to the membrane-localized leucine-rich repeat receptor kinase PEP RECEPTOR1 (PEPR1). Ligand binding induces PEPR1 heterodimerization with the co-receptor BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1), followed by PEPR1 internalization, both essential for a subset of Pep1-induced responses. However, the role of BAK1 in Pep1-triggered PEPR1 endocytosis remains unclear. Here, we show that the ligand-induced PEPR1 endocytosis depends on its kinase activity and requires BAK1 C-terminal tail phosphorylation, which is equally indispensable for immune signaling and BAK1 internalization. Using a GFP insertional mutagenesis approach, we generated a partially functional GFP-tagged BAK1 to demonstrate that, following Pep1 elicitation, BAK1 and PEPR1 are endocytosed together with similar dynamics. Our findings identify the BAK1 function as a prerequisite for PEPR1 internalization.

plant biology↗

The HOMEODOMAIN-Like protein HDL mediates chromatin organization and rewires leaf epidermal patterning

The Arabidopsis leaf epidermis is comprised of trichomes, pavement cells, and stomata, originating from versatile precursor cells capable of dividing or differentiating to create unique epidermal patterns. The mechanism governing these transitions and the maintenance of cell heterogeneity remains unclear. In this study, we identified a novel homeodomain-like superfamily protein, HDL, localized in chromocenters and playing a role in chromatin organization. HDL interacts with histone deacetylase 6 (HDA6) and methyltransferases, indicating its function in modulating chromatin accessibility. In hdl mutants, we observed moderately increased chromatin accessibility in the promoter region of protein-coding genes, along with reduced stomatal density and elevated trichome numbers on leaf surfaces. Corresponding to these phenotypes, stomatal-related gene expression decreased, while a transcriptional reporter for GLABRA2, a trichome initiation gene, exhibited higher and more variable expression levels. These findings highlight how HDL-mediated chromatin organization influences epidermal cell fate by modulating gene expression and enhancing cell heterogeneity within the leaf epidermis. One Sentence SummaryA homeodomain-like protein functions with histone modifiers to regulate chromatin and influence cell fate decisions.

plant biology↗

Misregulation of MYB16 causes stomatal cluster formation by disrupting polarity in asymmetric cell division

Stomata and leaf cuticle regulate water evaporation from the plant body and balance the trade-off between photosynthesis and water loss. We identified MYB16, a key transcription factor controlling cutin biosynthesis, from previous stomatal lineage ground cell (SLGC)-enriched transcriptome study. The preferential localization of MYB16 in SLGCs but not meristemoids suggests a link between cutin synthesis and stomatal development. Here, we showed that downregulation of MYB16 in meristemoids was directly mediated by the stomatal master transcription factor, SPEECHLESS (SPCH). The suppression of MYB16 before asymmetric division was crucial for stomatal patterning because overexpression or ectopic expression of MYB16 in meristemoids increased impermeability and elevated stomatal density and clusters. The aberrant pattern of stomata was due to reduced and disrupted establishment of polarity during asymmetric cell division. Manipulating polarity by growing seedlings on hard agar rescued stomatal clusters and polarity defects in MYB16 ectopic lines. By expressing a cutinase in MYB16 ectopic lines, stomatal clustering was reduced, which suggests that the ectopic accumulation of cuticle affects the polarity in asymmetrically dividing cells and causes clustered stomata. Taken together, inhibiting MYB16 expression by SPCH in early stomatal lineage is required to correctly place the polarity complex for proper stomatal patterning during leaf morphogenesis.

plant biology↗

Sequence variation among SARS-CoV-2 isolates in Taiwan

Taiwan experienced two waves of imported cases of coronavirus disease 2019 (COVID-19), first from China in January to late February, followed by those from other countries starting in early March. Additionally, several cases could not be traced to any imported cases and were suspected as sporadic local transmission. Twelve full viral genomes were determined in this study by Illumina sequencing either from virus isolates or directly from specimens, among which 5 originated from clustered infections. Phylogenetic tree analysis revealed that these sequences were in different clades, indicating that no major strain has been circulating in Taiwan. A deletion in open reading frame 8 was found in one isolate. Only a 4-nucleotide difference was observed among the 5 genomes from clustered infections.

genetics↗

Ecological occurrence and plant regeneration of embryoid of the endangered and endemic plant Dysosma versipellis in China

In this study, the effective callus culture, somatic embryogenesis, and plant regeneration system of Dysosma versipellis, which is an endangered and endemic plant in China, were established under specific culture conditions. Using the D. versipellis leaves, petioles, and roots as explants, DPS software orthogonal design method and SPSS Duncans multiple range test were used to investigate their effects of D. versipellis on callus formation, embryoid induction, and plant regeneration by adding different phytohormones. Results showed that leaves and petioles were the most suitable materials in inducing callus. The effect of phytohormone on callus formation followed the order of 2,4-dichlorophenoxyacetic acid (2,4-D)>thidiazuron (TDZ)> kinetin>naphthylacetic acid (NAA)>2-ip. The best medium for callus formation was MS+2,4-D 1 mg/L+NAA 0.05 mg/L+TDZ 0.5 mg/L+2-ip 1 mg/L. The optimal medium to induce the formation of granular callus embryoid was MS+0.5 mg/L 6-BA+0.1 mg/L NAA, and the induction rate was 71.33%. The embryoid rooting and plant regeneration medium was MS+0.5 mg/L IBA+0.5 mg/L GA3. The optimal medium formula obtained in this study was suitable for the rapid induction of callus, embryoid, and plant regeneration of D. versipellis under in vitro culture conditions. Further study on the action mechanism, signal regulation mechanism, and artificial seed production of fungal elicitors affecting the accumulation of podophyllotoxin is important.

plant biology↗