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: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.