Project description:RNA-seq analysis was performed on different developmental stages of cluster roots (pre-emergent, juvenile and mature) from Lupinus albus grown for 20 days under phosphorus-deficiency
Project description:During germination and early seedling development plants rely entirely on their seed storage compounds to provide energy and precursors for the synthesis of macromolecular structures such as cell walls until the seedling has emerged from the soil and photosynthesis can be established. Lupin seeds use proteins as their major storage compounds, accounting for up to 40% of the seed dry weight. Lupins are therefore a valuable complement to soy as a source of plant protein for human and animal nutrition. However, knowledge on protein and amino acid metabolism during germination and seedling establishment in lupin plants is still limited. The aim of this study was to elucidate how storage protein metabolism is coordinated with other metabolic processes to meet the requirements of the growing seedling. In a quantitative approach, we analyzed seedling growth, as well as alterations in biomass composition, the proteome, and metabolite profiles during germination and seedling establishment in Lupinus albus. The reallocation of nitrogen resources from seed storage proteins to functional seed proteins was mapped based on a manually curated functional protein annotation database. Although classified as a protein crop, Lupinus albus does not use amino acids as a primary resource during germination. The predominant role of the stored proteins is to act as a nitrogen resource for vigorous post-germinative growth. The degradation of storage lipids and carbohydrates is sufficient to meet the energy requirements for early seedling establishment until the onset of photosynthesis. However, our results suggest that during germination fatty acid and amino acid metabolism may be integrated at the level of malate synthase to combine stored carbon from lipids and proteins into gluconeogenesis.
