Project description:In plants, miR390 directs the production of tasiRNAs from TRANS-ACTING SIRNA 3 (TAS3) transcripts to regulate AUXIN RESPONSIVE FACTOR (ARF) genes, transcription factors critical for auxin signaling; these tasiRNAs are known as tasiARFs. This pathway is highly conserved, with the TAS3 as the only one noncoding gene present almost ubiquitously in land plants. To understand the evolution of this miR390-TAS3-ARF pathway, we characterized homologs of these three genes from thousands of plant species, from bryophytes to angiosperms. Both miR390 and TAS3 are present and functional in liverworts, confirming their ancestral role to regulate ARFs in land plants. We found the lower-stem region of MIR390 genes, critical for accurate DCL1 (DICER-LIKE 1) processing, is conserved in sequence in seed plants. We propose a model for the transition of functional tasiRNA sequences in TAS3 genes occurred at the emergence of vascular plants, in which the two miR390 target sites of TAS3 genes showed distinct pairing patterns in different plant lineages. Based on the cleavability of miR390 target sites and the distance between target site and tasiARF we inferred a potential bidirectional processing mechanism exists for some TAS3 genes. We also demonstrated a tight mutual selection between tasiARF and its target genes, and characterized unusual aspects and diversity of regulatory components of this pathway. Taken together, these data illuminate the evolutionary path of the miR390-TAS3-ARF pathway in land plants, and demonstrate the significant variation that occurs in the production of phasiRNAs in plants, even in the functionally important and archetypal miR390-TAS3-ARF regulatory circuit.
Project description:Pathways underlying miRNA biogenesis, degradation, and activity were established early in land plant evolution, but the 24-nt siRNA pathway that guides DNA methylation was incomplete in early land plants, especially lycophytes. We show that the functional diversification of key gene families such as DICER-LIKE and ARGONAUTE (AGO) as observed in angiosperms occurred early in land plants followed by parallel expansion of the AGO family in ferns and angiosperms. We uncovered an unexpected AGO family specific to lycophytes and ferns. Our phylogenetic analyses of miRNAs in lycophytes, bryophytes, ferns, and angiosperms refined the temporal origination of conserved miRNA families in land plants.
Project description:Proteomics data used in the evaluation of Micromonas pusilla as part of a larger comparison associated with marine diversity and ancestral characteristics of land plants
Project description:The colonization of land by plants relies on numerous evolutionary innovations crucial for terrestrial adaptation. These include advances in sexual reproduction and the ability to properly respond to various environmental stresses, which involve precise control of their regulatory genes. A notable genetic innovation in land plants is the emergence of histone lysine methyltransferases ATXR5/6, which specifically catalyse the repressive histone H3 lysine 27 monomethylation (H3K27me1). However, the evolutionary reason for land plants to develop these enzymes remains unclear. In this study, we investigate the importance of ATXR5/6 by generating strong atxr5;axtr6 double mutants in Arabidopsis. Our results show that ATXR5/6 are essential for plant reproductive development and play a critical role in supporting normal plant growth by repressing the transcription of stress responsive genes. In addition, ATXR5/6 are necessary for maintaining H3K27 trimethylation (H3K27me3), likely by providing H3K27me1 as a substrate for further methylation. We also demonstrate that the function of ATXR5/6 in regulating reproductive development and responsive genes is conserved in the monocot rice. We propose that land plants may have evolved ATXR5/6 to assist in the transcriptional regulation necessary for terrestrial adaptation
Project description:Telomere homeostasis, crucial for various biological processes, relies on telomerase activity. We identified ZC3H15 as a novel telomerase-interacting protein. Its deletion unexpectedly increased telomerase activity but led to shortened telomeres and cellular senescence. ZC3H15 interacts with telomerase and itself, regulating telomerase activity in an RNA-dependent manner. Proximity labeling showed ZC3H15's interaction with proteins involved in organelle assembly and RNA processes. Loss of ZC3H15 sequestered TERC in the Cajal body, reducing telomerase recruitment to telomeres during S phase. These findings unveil ZC3H15's role in telomere dynamics and cellular senescence, suggesting its potential as a target for cancer therapy or anti-aging interventions.
Project description:The Streptophyta include unicellular and multicellular charophyte green algae and land plants. Colonization of the terrestrial habitat by land plants was a major evolutionary event that has transformed our planet. So far lack of genome information on unicellular charophyte algae hinders our understanding of the origin and the evolution from unicellular to multicellular life in Streptophyta. This work reports the high-quality reference genome and transcriptome of Mesostigma viride, a single-celled charophyte alga with a position at the base of Streptophyta. There are abundant segmental duplications and transposable elements in M. viride, which contribute to a relatively large genome with high gene content compared to other algae and early diverging land plants. This work identifies the origin of genetic tools that multicellular Streptophyta have inherited and key genetic innovations required for evolution of land plants from unicellular aquatic ancestors. The findings shed light on the age-old questions of the evolution of multicellularity and the origin of land plants.
Project description:The Streptophyta include unicellular and multicellular charophyte green algae and land plants. Colonization of the terrestrial habitat by land plants was a major evolutionary event that has transformed our planet. So far lack of genome information on unicellular charophyte algae hinders our understanding of the origin and the evolution from unicellular to multicellular life in Streptophyta. This work reports the high-quality reference genome and transcriptome of Mesostigma viride, a single-celled charophyte alga with a position at the base of Streptophyta. There are abundant segmental duplications and transposable elements in M. viride, which contribute to a relatively large genome with high gene content compared to other algae and early diverging land plants. This work identifies the origin of genetic tools that multicellular Streptophyta have inherited and key genetic innovations required for evolution of land plants from unicellular aquatic ancestors. The findings shed light on the age-old questions of the evolution of multicellularity and the origin of land plants.
Project description:The rapid production of reactive oxygen species (ROS) is a key signaling output in plant immunity. In the angiosperm model species, Arabidopsis thaliana (hereafter Arabidopsis), recognition of non- or altered-self elicitor patterns by cell-surface immune receptors activates the receptor-like cytoplasmic kinases (RLCKs) of the AVRPPHB SUSCEPTIBLE 1 (PBS1)-like (PBL) family, particularly BOTRYTIS-INDUCED KINASE1 (BIK1)1–3. BIK1/PBLs in turn phosphorylate the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase RESPIRATORY BURST OXIDASE HOMOLOG D (RBOHD) to induce apoplastic ROS production4,5. PBL and RBOH functions in plant immunity have been extensively characterized in flowering plants. Much less is known about the conservation of pattern-triggered ROS signaling pathways in non-flowering plants. In this study, we show that, in the liverwort Marchantia polymorpha (hereafter Marchantia), single members of RBOH and PBL families, namely MpRBOH1 and MpPBLa, are required for chitin-induced ROS production. MpPBLa directly interacts with and phosphorylates MpRBOH1 at specific, conserved sites within its cytosolic N-terminus and this phosphorylation is essential for chitin-induced MpRBOH1-mediated ROS production. Collectively, our work reveals the functional conservation of the PBL-RBOH module that controls pattern-triggered ROS production in land plants.
Project description:This experiment probed for the presence of known Arabidopsis and rice microRNAs in total RNA samples derived from species representative of the major groups of land plants: Eudicots (Arabidopsis thaliana, Nicotiana benthamiana), monocots (Oryza satica, Triticum aestivum), magnoliids (Liriodendron tulipifera), gymnosperms (Pinus resinosa), ferns (Ceratopteris thalictroides), lycopods (Selaginella uncinata), and mosses (Polytrichum juniperinum). In most cases two technical or biological replicates were performed.
Project description:The colonization of land by plants relies on numerous evolutionary innovations crucial for terrestrial adaptation. These include advances in sexual reproduction and the ability to properly respond to various environmental stresses, which involve precise control of their regulatory genes. A notable genetic innovation in land plants is the emergence of histone lysine methyltransferases ATXR5/6, which specifically catalyse the repressive histone H3 lysine 27 monomethylation (H3K27me1). However, the evolutionary reason for land plants to develop these enzymes remains unclear. In this study, we investigate the importance of ATXR5/6 by generating strong atxr5;axtr6 double mutants in Arabidopsis. Our results show that ATXR5/6 are essential for plant reproductive development and play a critical role in supporting normal plant growth by repressing the transcription of stress responsive genes. In addition, ATXR5/6 are necessary for maintaining H3K27 trimethylation (H3K27me3), likely by providing H3K27me1 as a substrate for further methylation. We also demonstrate that the function of ATXR5/6 in regulating reproductive development and responsive genes is conserved in the monocot rice. We propose that land plants may have evolved ATXR5/6 to assist in the transcriptional regulation necessary for terrestrial adaptation