Project description:Watershield (Brasenia schreberi) is an aquatic plant that belongs to the basal angiosperm family Cabombaceae. This species has been cultivated as an aquatic vegetable for more than 3000 years in East Asia, but the natural populations have greatly declined in recent decades and have become endangered in several countries of East Asia. In this study, by using PacBio long reads, Illumina short reads, and Hi-C sequencing data, we assembled the genome of B. schreberi, which was approximately 1170.4 Mb in size with a contig N50 of 7.1 Mb. Of the total assembled sequences, 93.6% were anchored to 36 pseudochromosomes with a scaffold N50 of 28.9 Mb. A total of 74,699 protein-coding genes were predicted in the B. schreberi genome, and 558 Mb of repetitive elements occupying 47.69% of the genome were identified. BUSCO analysis yielded a completeness score of 95.8%. The assembled high-quality genome of B. schreberi will be a valuable reference for the study of conservation, evolution and molecular breeding in this species.
Project description:Brasenia schreberi is a critically endangered aquatic basal angiosperm. In this work, we characterized the structure of the glandular trichomes of B. schreberi morphologically and histochemically. We used a variety of structural, histochemical and permeability stains for the characterization, and we tested the effects of stress in vivo using NaCl and ethanol. We observed that the glandular trichome of B. schreberi are composed of two disk-like stalk cells, and a glandular cell which surround a cuticular storage space. The cuticle is discontinuous at the surface of the shoots. Nearly half of young trichomes senesced in 0.9% NaCl, and mature trichomes senesced at 1.8% NaCl. About half of young trichomes senesced under 3% ethanol and mature trichomes senesced in 2% ethanol after 20 min of treatment. The physiology of glandular trichomes affects the way they secrete mucilage via storage space at a young stage. The trichomes become permeable and absorb ions when mature. This transition depends on the osmiophilic material and the dynamic protoplast. It can accelerate senescence and disassembly by ion accumulation. Permeability tests and ion treatments of glandular trichomes provide new insights for fertilizer research. Our study highlights the structure and physiology of B. schreberi glandular trichomes.
Project description:Brasenia schreberi is a perennial aquatic herb. We determined the complete chloroplast genome sequence for B. schreberi using Illumina sequencing data. The complete chloroplast sequence is 158,993 bp, include large single-copy (LSC) region of 88,779 bp, small single-copy (SSC) region of 21,665 bp, a pair of invert repeats (IR) regions of 21,078 bp. Plastid genome contains 132 genes, 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis base on 12 chloroplast genomes indicates that B. schreberi is sister to Cabomba spp. in Cabombaceae.
Project description:ObjectivesBrasenia is a monotypic genus in the family of Cabombaceae. The only species, B. schreberi, is a macrophyte distributed worldwide. Because it requires good water quality, it is endangered in China and other countries due to the deterioration of aquatic habitats. The young leaves and stems of B. schreberi are covered by thick mucilage, which has high medical value. As an allelopathic aquatic plant, it can also be used in the management of aquatic weeds. Here, we present its assembled and annotated genome to help shed light on medial and allelopathic substrates and facilitate their conservation.Data descriptionGenomic DNA and RNA extracted from B. schreberi leaf tissues were used for whole genome and RNA sequencing using a Nanopore and/or MGI sequencer. The assembly was 1,055,148,839 bp in length, with 92 contigs and an N50 of 22,379,495 bp. The repetitive elements in the assembly were 555,442,205 bp. A completeness assessment of the assembly with BUSCO and compleasm indicated 88.4 and 90.9% completeness in the Eudicots database and 95.4 and 96.6% completeness in the Embryphyta database. Gene annotation revealed 67,747 genes that coded for 73,344 proteins.
Project description:Brasenia schreberi is a widely consumed aquatic plant, yet the knowledge regarding its bioactive components, particularly polysaccharides, remains limited. Therefore, this study aimed to optimize the extraction process of polysaccharides from B. schreberi using the response surface method (RSM). Additionally, we characterized the polysaccharides using various methods and assessed their antioxidant capabilities both in vitro and in vivo, employing cell cultures and Caenorhabditis elegans. Furthermore, these polysaccharides were incorporated into a unique yogurt formulation. Our findings demonstrated that hot water extraction was the most suitable method for extracting polysaccharides from B. schreberi, yielding samples with high sugar content, significant antioxidant capacity, and a well-defined spatial structure. Moreover, pectinase was employed for polysaccharide digestion, achieving an enzymolysis rate of 10.02% under optimized conditions using RSM. Notably, the results indicated that these polysaccharides could protect cells from oxidative stress by reducing apoptosis. Surprisingly, at a concentration of 250 μg/mL, the polysaccharides significantly increased the survival rate of C. elegans from 31.05% to 82.3%. Further qPCR results revealed that the polysaccharides protected C. elegans by up-regulating the daf-16 gene and down-regulating mTOR and insulin pathways, demonstrating remarkable antioxidant abilities. Upon addition to the yogurt, the polysaccharides significantly enhanced the water retention, viscosity, and viability of lactic acid bacteria. These outcomes underscore the potential of polysaccharides from B. schreberi as a valuable addition to novel yogurt formulations, thereby providing additional theoretical support for the utilization of B. schreberi.