Project description:Sacred lotus (Nelumbo nucifera) belongs to Nelumbonaceae family. Its seeds are widely consumed in Asia countries as snacks or even medicine. Besides the market values, lotus seed also plays crucial roles in lotus life cycle. Consequently, it is essential to gain a comprehensive understanding on the development of lotus seed. During its development, lotus seed undergoes cell division, expansion, reserve accumulation, desiccation and maturation phases. We observed the morphological and biochemical changes of lotus seed from 10 to 25 days after pollination (DAP) which was corresponding to the reserve synthesis and accumulation phase. The volume of the seed expanded until 20 DAP with the color of the seed coat changing from yellow-green to dark green and gradually faded again. Starch and protein rapidly accumulated from 15 to 20 DAP. To further reveal the metabolism adaptation, primary metabolites and proteins profiles were obtained from the mass spectrometry based platforms. Metabolites and enzymes involved in sugar metabolism, glycolysis, TCA cycle and amino acids metabolism schematized on their biosynthetic pathways. Both metabolic and proteomic profiles indicated more active metabolism from 10 to 15 DAP than after 20 DAP. The results provide a frame of reference for the evaluation of primary metabolism during lotus seed development.
2022-02-22 | PXD003768 | Pride
Project description:The transcriptome of lotus seed cotyledon
Project description:Lotus is an aquatic plant that is sensitive to water loss, but its seeds are longevous after seed embryo dehydration and maturation. The great difference between the responses of vegetative organs and seeds to dehydration is related to the special protective mechanism in embryos. In this study, tandem mass tags (TMT)-labeled proteomics and parallel reaction monitoring (PRM) technologies were used to obtain novel insights into the physiological regulatory networks during lotus seed dehydration process. Totally, 60,266 secondary spectra and 32,093 unique peptides were detected. A total of 5,477 reliable proteins and 815 differentially expressed proteins (DEPs) were identified based on TMT data; of these, 582 DEPs were continuously down-regulated and 228 proteins were significantly up-regulated during the whole dehydration process. Bioinformatics and protein-protein interaction network analyses indicated that carbohydrate metabolism (including glycolysis/gluconeogenesis, galactose, starch and sucrose metabolism, pentose phosphate pathway, and cell wall organization), protein processing in ER, DNA repair, and antioxidative events had positive responses to lotus embryo dehydration. On the contrary, energy metabolism (metabolic pathway, photosynthesis, pyruvate metabolism, fatty acid biosynthesis) and secondary metabolism (terpenoid backbone, steroid, flavonoid biosynthesis) gradually become static status during lotus embryo water loss and maturation. Furthermore, non-enzymatic antioxidants and pentose phosphate pathway play major roles in antioxidant protection during dehydration process in lotus embryo; ABA signaling and the accumulation of oligosaccharides, late embryogenesis abundant proteins, and heat shock proteins may be the key factors to ensure the continuous dehydration and storage tolerance of lotus seed embryo. Stress physiology detection showed that H2O2 was the main ROS component inducing oxidative stress damage, and glutathione and vitamin E acted as the major antioxidant to maintain the REDOX balance of lotus embryo during the dehydration process. These results provide new insights to reveal the physiological regulatory networks of the protective mechanism of embryo dehydration in lotus.
Project description:Lotus japonicus is a perennial legume with a small diploid genome that has been adopted as a model species for legume genetics and genomics. With the genome sequence as a backdrop (Sato et al. 2008), we have generated a gene expression atlas that provides a global view of gene expression in all major organ systems of this species, including nodule and seed development.
Project description:Flower-lotus with many attractive floral characteristics has been studied and discussed the most. These characteristics are used as the standards of the classification in most cases, and always attracted the attention of lotus breeders on improvement program because of associating with ornamental and economic values of lotus. However, molecular mechanisms underlying the formation of these attractive floral features still remain largely unknown. Transcriptome sequencing technique has been established as an efficient approach for gene discovery and expression pattern identification. For some plants, a lot of important genes involved in plant critical metabolisms have been successfully identified by this technique. In the study, mass sequence data obtained from the deep sequencing of a mixed flower-bud cDNA pool from three individuals of N. nucifera provide a platform to comprehensively understand the processes of flower formation and development at the molecular level, and will greatly facilitate the genetic improvement of ornamental characteristics and the directive molecular breeding for lotus in the future.
Project description:Lotus japonicus is a model legume broadly used to study transcriptome regulation under different stress conditions and microorganism interaction. Understanding how this model plant protects itself against pathogens will certainly help to develop more tolerant cultivars in economically important Lotus species as well as in other legumes. In order to uncover the most important defense mechanisms activated upon bacterial attack, we explored by microarray analysis the transcriptome regulation occurring in the phenotypically contrasting ecotypes MG-20 and Gifu B-129 of L. japonicus after inoculation with the non-pathogenic strain Pseudomonas syringae DC3000 pv. tomato.
Project description:Lotus japonicus is a model legume broadly used to study transcriptome regulation under different stress conditions and microorganism interaction. Understanding how this model plant respond gainst alkaline stress will certainly help to develop more tolerant cultivars in economically important Lotus species as well as in other legumes. In order to uncover the most important response mechanisms activated during alkaline stress, we explored by microarray analysis the transcriptome regulation occurring in the phenotypically contrasting ecotypes MG-20 and Gifu B-129 of L. japonicus after 21 days of alkaline stress.
Project description:To identify the regulatory targets of the R2R3-Myb transcription factor, LjMyb14, the gene was constitutively over-expressed in Lotus japonicus under the Lotus ubiquitin promoter. The gene expression levels of three biological replicates of the Lotus japonicus (MG20) were averaged and compared to the the gene expression levels of three independent lines of Lotus japonicus japonicus constituitively over expressing LjMyb14 using the Lotus ubiquitin promoter.