Open AccessIncreased zinc content in transplastomic tobacco plants expressing a polyhistidine‐tagged Rubisco large subunit
Author(s) -
Rumeau Dominique,
BécuweLinka Noëlle,
Beyly Audrey,
Carrier Patrick,
Cuiné Stéphan,
Genty Bernard,
Medgyesy Peter,
Horvath Eva,
Peltier Gilles
Publication year - 2004
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/j.1467-7652.2004.00083.x
Subject(s) - rubisco , biology , plastid , protein subunit , biochemistry , gene , nicotiana tabacum , chloroplast , botany
Summary Rubisco is a hexadecameric enzyme composed of two subunits: a small subunit (SSU) encoded by a nuclear gene ( rbcS ), and a large subunit (LSU) encoded by a plastid gene ( rbcL ). Due to its high abundance, Rubisco represents an interesting target to express peptides or small proteins as fusion products at high levels. In an attempt to modify the plant metal content, a polyhistidine sequence was fused to Rubisco, the most abundant protein of plants. Plastid transformation was used to express a polyhistidine (6×) fused to the C‐terminal extremity of the tobacco LSU. Transplastomic tobacco plants were generated by cotransformation of polyethylene glycol‐treated protoplasts using two vectors: one containing the 16SrDNA marker gene, conferring spectinomycin resistance, and the other the polyhistidine‐tagged rbcL gene. Homoplasmic plants containing L 8 ‐(His) 6 S 8 as a single enzyme species were obtained. These plants contained normal Rubisco amounts and activity and displayed normal photosynthetic properties and growth. Interestingly, transplastomic plants accumulated higher zinc amounts than the wild‐type when grown on zinc‐enriched media. The highest zinc increase observed exceeded the estimated chelating ability of the polyhistidine sequence, indicating a perturbation in intracellular zinc homeostasis. We discuss the possibility of using Rubisco to express foreign peptides as fusion products and to confer new properties to higher plants.