Zeolin is a recombinant storage protein that can be used to produce value-added proteins in alfalfa (Medicago sativa L.)

Abstract

The specific features of plants make them particularly suitable for the production of recombinant proteins and alfalfa is one of the recommended plant production systems. We have transformed alfalfa with a gene coding for a chimaeric protein made previously by fusing phaseolin to the Nterminal region of c-zein and have analyzed the accumulation of this fusion protein, named zeolin. Zeolin was expressed both in T0 Regen SY alfalfa plants and in the progeny resulting from the sexual cross between Regen SY transformants and alfalfa cv. Adriana plants. In some alfalfa plants a 95 kDa zeolin glycosylated polypeptide is the most abundant polypeptide detected by Western-blot analysis, whereas in tobacco the most abundant zeolin polypeptide has a molecular mass around 60 kDa, expected for intact zeolin. Zeolin has been stably accumulated in alfalfa leaves because it forms endoplasmic reticulum-located protein bodies in the cell. As regards zeolin quantisation, in the progeny alfalfa plants a value of about 0.22-0.28 mg of zeolin / g of fresh leaf weight has been estimated.

Transgenic Biofortification of the Starchy Staple Cassava (Manihot esculenta) Generates a Novel Sink for Protein

“…Four distinct forms of zeolin were observed ( Figure S2 ), and respective levels of abundance determined by band intensity. Approximately 6% of the total zeolin was found present as a monomer, 76% as a trimer, 14% as a trimer bound to BiP chaperone, and 4% in a higher molecular weight, glycosylated form [16] , [18] . When protein bodies were isolated without a reducing agent and loaded onto a native polyacrylamide gel, band patterning showed a higher molecular weight than expected for zeolin ( Figure S2 ), once more suggesting that other proteins were associated with the transgenically expressed product.…”

“…Zeolin is a fusion product between phaseolin, the major storage protein in common beans ( Phaseolus vulgaris ), and a truncated gamma-zein protein from maize ( Zea mays ), which directs the fused polypeptide to form stable protein bodies within the ER [15]. Previous reports have shown expression of zeolin to result in significant accumulation of this storage protein in leaf tissues of tobacco and alfalfa [16]. We report here production of transgenic cassava plants expressing zeolin in which storage roots accumulated up to 12.5% dw protein, a greater than fourfold increase compared to controls with no associated accumulation of the protein product in leaf tissues.…”

Biofortification of Soybean Meal: Immunological Properties of the 27 kDa γ-Zein

“…In the case of barley, the 27 kDa γ-zein was expressed for the purpose of altering the grain soft texture to hard-textured endosperm . Additionally, chimeric protein (zeolin) composed of phaseolin, the seed storage protein of common beans and 89 amino acids of γ-zein, has been expressed in tobacco and alfalfa. , The zeolin, which accumulated to very high levels in tobacco, was localized in the ER-located protein bodies. The success of this approach has prompted the use of γ-zein to stably produce value-added proteins in plants .…”

Optimization and establishment of Agrobacterium-mediated transformation in alfalfa (Medicago sativa L.) using eGFP as a visual reporter

“…Alfalfa (Medicago sativa L.) has been an important leguminous forage species grown globally due to its high nutritional feeding values and pharmaceutical application potential (Bellucci et al 2007;Bouton 2007; Radović et al 2009). Development and establishment of highly e cient genetic transformation procedure in alfalfa will provide an important platform for introduction of agronomically and commercially important traits and thus facilitates genetically engineering of alfalfa.…”