Ectopic expression of amaranth seed storage albumin modulates photoassimilate transport and nutrient acquisition in sweetpotato

Abstract

Storage proteins in plants, because of high nutrient value, have been a subject of intensive investigation. These proteins are synthesized de novo in the cytoplasm and transported to the storage organelles where they serve as reservoir of energy and supplement of nitrogen during rapid growth and development. Sweetpotato is the seventh most important food crop worldwide, and has a significant contribution to the source of nutrition, albeit with low protein content. To determine the behaviour of seed storage proteins in non-native system, a seed albumin, AmA1, was overexpressed in sweetpotato with an additional aim of improving nutritional quality of tuber proteins. Introduction of AmA1 imparted an increase in protein and amino acid contents as well as the phytophenols. The proteometabolomics analysis revealed a rebalancing of the proteome, with no significant effects on the global metabolome profile of the transgenic tubers. Additionally, the slower degradation of starch and cellulose in transgenic tubers, led to increased post-harvest durability. Present study provides a new insight into the role of a seed storage protein in the modulation of photoassimilate movement and nutrient acquisition.

Advances in the Biology of Seed and Vegetative Storage Proteins Based on Two-Dimensional Electrophoresis Coupled to Mass Spectrometry

“…Some strategies rely on the ectopic expression of transgenes coding for high quality proteins that correct seed deficiencies in the amino acid composition of storage proteins. Shekhar et al [ 50 ] introduced the seed albumin gene AmA1 from Amaranthus hypochondriacus into sweet potato ( Ipomoea batatas L.) by Agrobacterium-mediated transformation to assess the behavior of storage proteins in a non-native system. AmA1 is rich in all EAA whereas sweet potato proteins are deficient in tryptophan and sulfur-containing amino acids.…”

“…These advances cover facets as diverse as the identification of isoforms and their relative abundance, the identification, mapping and quantitation of phosphorylated and glycosylated isoforms and the assessment of qualitative and quantitative changes of isoforms during seed development and germination. Seed breeding programs have benefited from these advances for the improvement of many seed traits of interest such as protein quality, longevity, gluten and allergen content, stress response and antifungal, antibacterial and insect susceptibility [ 45 , 46 , 47 , 48 , 49 , 50 , 51 ].…”

Wheat 2‐Cys peroxiredoxin plays a dual role in chlorophyll biosynthesis and adaptation to high temperature

“…Metabolites were analyzed and identified by comparing their mass spectra with that from the NIST and/or Wiley library. The abundance of individual metabolites was normalized against internal standards, ribitol (2 mg ml À1 ) and 2-methyl-3-heptanone (1.424 µg µl À1 ), as previously described (Shekhar et al, 2016a).…”

Involvement of nitrogen in storage root growth and related gene expression in sweet potato (Ipomoea batatas)

“…Sweet potato ( Ipomoea batatas ) is one of the most important food crops worldwide (Bovell‐Benjamin ; Shekhar et al ., ; Mukhongo et al ., ). China is a major producer of sweet potato, the production of sweet potato was 72,031,782 tonnes in China, producing approximately 64% of the world's supply (FAOSTAT, ).…”