Project description:Pea (Pisum. sativum L.) is a traditional and important edible legume that can be sorted into grain pea and vegetable pea according to their harvested maturely or not. Vegetable pea by eating the fresh seed is becoming more and more popular in recent years. These two type peas display huge variations of the taste and nutrition, but how seed development and nutrition accumulation of grain pea and vegetable pea and their differences at the molecular level remains poorly understood. To understand the genes and gene networks regulate seed development in grain pea and vegetable pea, high throughput RNA-Seq and bioinformatics analysis were used to compare the transcriptomes of vegetable pea and grain pea developing seed. RNA-Seq generated 18.7 G raw data, which was then de novo assembled into 77,273 unigenes with a mean length of 930 bp. Functional annotation of the unigenes was carried out using the nr, Swiss-Prot, COG, GO and KEGG databases. There were 459 and 801 genes showing differentially expressed between vegetable pea and grain pea at early and late seed maturation phases, respectively. Sugar and starch metabolism related genes were dramatically activated during pea seed development. The up-regulated of starch biosynthesis genes could explain the increment of starch content in grain pea then vegetable pea; while up-regulation of sugar metabolism related genes in vegetable pea then grain pea should participate in sugar accumulation and associated with the increase in sweetness of vegetable pea then grain pea. Furthermore, transcription factors were implicated in the seed development regulation in grain pea and vegetable pea. Thus, our results constitute a foundation in support of future efforts for understanding the underlying mechanism that control pea seed development and also serve as a valuable resource for improved pea breeding.
Project description:12plex_pea_2013_02 - 12plex_pea_2013_02_g - What is the effect of a moderate water stress on seed filling (reserve accumulation) and nitrogen remobilisation in pea (Pisum sativum) - Pea plants (genotype Cameor) were subjected to a moderate water stress at the beggining of the seed filling period (12 Days After Pollination) of the second flowering node for a period of 8 days. Samples were collected from Well Watered (WW) plants at the beginning of the stress imposition (point A, T=0), and from Water-Stressed (WS) and WW control plants at the end of the drought period (point B, T=+8). Samples named SEED consisted of seeds from the pod of the second flowering node (seed-WW-A, seed-WW-B and Seed-WS-B). Samples named LEAF consisted of the leaves and stem sections from the two vegetative nodes below the first flowering node (leaf-WW-A, Leaf-WW-B and Leaf-WS-B). Each sample consited of a pool of 3 individual plants and 4 repetitions per condition were carried out.
Project description:12plex_pea_2013_02 - 12plex_pea_2013_02_f - What is the effect of a moderate water stress on seed filling (reserve accumulation) and nitrogen remobilisation in pea (Pisum sativum) - Pea plants (genotype Cameor) were subjected to a moderate water stress at the beggining of the seed filling period (12 Days After Pollination) of the second flowering node for a period of 8 days. Samples were collected from Well Watered (WW) plants at the beginning of the stress imposition (point A, T=0), and from Water-Stressed (WS) and WW control plants at the end of the drought period (point B, T=+8). Samples named SEED consisted of seeds from the pod of the second flowering node (seed-WW-A, seed-WW-B and Seed-WS-B). Samples named LEAF consisted of the leaves and stem sections from the two vegetative nodes below the first flowering node (leaf-WW-A, Leaf-WW-B and Leaf-WS-B). Each sample consited of a pool of 3 individual plants and 4 repetitions per condition were carried out.
Project description:Seed development is a complex process controlled by many factors, including genetics, plant growth regulators, and the environment. Understanding the different compositions and abundances of proteins in various types of seeds at different developmental stages is fundamental for improving seed quality and enhancing nutritional and food security. In this study, we applied label-free quantitative proteomics to analyze round and wrinkled pea seeds at five different growth stages: 4, 7, 12, 15 days after anthesis (DAA), and at maturity. Wrinkled peas had lower starch content (29.5%) compared to round peas (~47-55%). Proteomic analysis identified 3,659 protein groups, of which approximately 21-24% proteins were shared across growth stages. Relatively more proteins were identified during early seed development compared to later stages, and the protein profiles were also drastically different between early and late stages. Statistical analysis identified 735 significantly different proteins between wrinkled and round seeds, regardless of the growth stage. These detected proteins were characterized into different functional classes including metabolic enzymes, proteins involved in protein biosynthesis and homeostasis, carbohydrate metabolism, vesicle trafficking, cell division, and cell wall organization. Cell division-related proteins were more abundant in the early stages of seed development, whereas storage proteins and proteins implicated in lipid metabolism were more abundant at the later stages. Wrinkled seeds had a significantly lower abundance of starch-branching enzyme than did round seeds. This enzyme is involved in the biosynthesis of the amylopectin component of starch. Seed storage proteins such as legumin and a form of albumin (PA2) accumulated more in round pea genotypes, whereas vicilin was more abundant in the wrinkled pea genotype. In summary, this study can enhance our understanding of pea seed development, highlighting key differences in protein profiles between round and wrinkled pea seeds.
Project description:During seed growth, sugar and nitrogen compounds confer regulatory control on storage activities. Thus, seed storage production could be regulated by the supply of nutrients. In order to improve nitrogen flux into the embryo, transgenic pea lines were created where ADP-glucose pyrophosphorylase (AGP) from Pisum sativum has been repressed by RNAi approach in the seeds under control of the seed-specific LeB4 promotor (Bäumlein et al. Cis-analysis of a seed protein gene promoter: the conservative RY repeat CATGCATG within legumin box is essential for tissue-specific expression of a legumin gene. Plant J 1992 2: 233-239). The plastidial enzyme AGP catalyzes the reaction of glucose-1-phosphate and ATP to pyrophosphate and ADP-glucose, which is the substrate for starch synthase. The AGP activity and transcript levels were strongly decreased in three independent transgenic lines. Repression of AGP results in a wrinkled seed phenotype obviously due to transient accumulation of free sugars during maturation. Mature seeds have reduced starch content whereas the protein concentration is higher due to increased fractions of albumins and globulins. Repression of AGP interferes with storage protein metabolism and alters fluxes of nitrogen during seed growth. The influence of decreased AGP on altered gene expression in developing cotyledons was analysed using a 6k-Oligo-microarray. Ps6kOLI1 microarray hybridization were performed using three independent biological replicates of four developmental stages (20, 25, 30 and 35 DAP) from seeds of the transgenic line iAGP-3.