The mantled phenotype is an abnormal somaclonal variant arising from the oil palm cloning process and severe phenotypes lead to oil yield losses. Hypomethylation of the Karma retrotransposon within the B-type MADS-box EgDEF1 gene has been associated with this phenotype. While abnormal Karma-EgDEF1 hypomethylation was detected in mantled clones, we examined the methylation state of Karma in ortets that gave rise to high mantling rates in their clones.
View Article and Find Full Text PDFArabinogalactan proteins are functionally diverse cell wall structural glycoproteins that have been implicated in cell wall remodeling, although the mechanistic actions remain elusive. Here, we identify and characterize two AGP glycoproteins, SLEEPING BEAUTY (SB) and SB-like (SBL), that negatively regulate the gametophore bud initiation in Physcomitrium patens by dampening cell wall loosening/softening. Disruption of SB and SBL led to accelerated gametophore formation and altered cell wall compositions.
View Article and Find Full Text PDFLight is a critical signal perceived by plants to adapt their growth rate and direction. Although many signaling components have been studied, how plants respond to constantly fluctuating light remains underexplored. Here, we showed that in the moss () , the PSTAIRE-type cyclin-dependent kinase PpCDKA is dispensable for growth.
View Article and Find Full Text PDFSmall signalling peptides are key molecules for cell-to-cell communications in plants. The cysteine-rich signalling peptide, rapid alkalinisation factors (RALFs) family are involved in diverse developmental and stress responses and have expanded considerably during land plant evolution, implying neofunctionalisations in the RALF family. However, the ancestral roles of RALFs when land plant first acquired them remain unknown.
View Article and Find Full Text PDFDuring the immune response, activation of the secretory pathway is key to mounting an effective response, while gauging its output is important to maintain cellular homeostasis. The Exo70 subunit of the exocyst functions as a spatiotemporal regulator by mediating numerous interactions with proteins and lipids. However, a molecular understanding of the exocyst regulation remains challenging.
View Article and Find Full Text PDFChloroplast division is a critical process for the maintenance of appropriate chloroplast number in plant cells. It is known that in some plant species and cell types, environmental stresses can affect chloroplast division, differentiation and morphology, however the significance and regulation of these processes are largely unknown. Here we investigated the regulation of salt stress-induced chloroplast division in protonemal cells of the moss, Physcomitrella patens, and found that, salt stress as one of the major abiotic stresses, induced chloroplast division and resulted in increased chloroplast numbers.
View Article and Find Full Text PDFVacuolar trafficking plays a vital role in plant growth and development. In this chapter, we describe a powerful technique for the evaluation of vacuolar protein trafficking, which is designated as GREEN FLUORESCENT SEED. Based on vacuole-targeted green fluorescent protein in Arabidopsis seeds, this method enables the nondestructive isolation of mutant seeds defective in vacuolar trafficking and their visual characterization.
View Article and Find Full Text PDFXBAT35 belongs to a subfamily of Arabidopsis () RING-type E3s that are similar in domain architecture to the rice () XA21 Binding Protein3, a defense protein. The transcript undergoes alternative splicing to produce two protein isoforms, XBAT35.1 and XBAT35.
View Article and Find Full Text PDFMembrane trafficking is required during plant immune responses, but its contribution to the hypersensitive response (HR), a form of programmed cell death (PCD) associated with effector-triggered immunity, is not well understood. HR is induced by nucleotide binding-leucine-rich repeat (NB-LRR) immune receptors and can involve vacuole-mediated processes, including autophagy. We previously isolated lazarus (laz) suppressors of autoimmunity-triggered PCD in the Arabidopsis thaliana mutant accelerated cell death11 (acd11) and demonstrated that the cell death phenotype is due to ectopic activation of the LAZ5 NB-LRR.
View Article and Find Full Text PDFMembrane trafficking to the protein storage vacuole (PSV) is a specialized process in seed plants. However, this trafficking mechanism to PSV is poorly understood. Here, we show that three types of Beige and Chediak-Higashi (BEACH)-domain proteins contribute to both vacuolar protein transport and effector-triggered immunity (ETI).
View Article and Find Full Text PDFPlants respond to pathogen attack with dynamic rearrangements of the endomembrane system and rapid redirection of membrane traffic to facilitate effective host defence. Mounting evidence indicates the involvement of endocytic, secretory, and vacuolar trafficking pathways in immune receptor activation, signal transduction, and execution of multiple defence responses including programmed cell death (PCD). Autophagy is a conserved intracellular trafficking and degradation process and has been implicated in basal immunity as well as in some forms of immune receptor-mediated vacuolar cell death.
View Article and Find Full Text PDFFormation of clathrin-coated vesicles (CCVs) requires the scaffolding adaptor protein (AP) complexes, which are conserved across all eukaryotes. The Arabidopsis genome encodes five AP complexes (AP-1 to AP-5), and each complex consists of four subunits. In this study, we characterized the poorly defined AP-1 complex by using genetics, proteomics and live cell imaging.
View Article and Find Full Text PDFAs the world population grows, the demand for food increases. Although vegetable oils provide an affordable and rich source of energy, the supply of vegetable oils available for human consumption is limited by the "fuel vs food" debate. To increase the nutritional value of vegetable oil, metabolic engineering may be used to produce oil crops of desirable fatty acid composition.
View Article and Find Full Text PDFCircumstantial evidence suggests that intracellular membrane trafficking pathways diversified independently in the plant kingdom, but documented examples are rare. ARF-GEFs (guanine-nucleotide exchange factors for ADP-ribosylation factor GTPases) are essential for vesicular trafficking in all eukaryotic kingdoms, but of the eight ARF-GEF families, only the ancestral BIG and GBF types are found in plants. Whereas fungal and animal GBF proteins perform conserved functions at the Golgi, the Arabidopsis thaliana GBF protein GNOM is thought to act in only the process of recycling from endosomes.
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