The sweet potato sporamin promoter confers high-level phytase expression and improves organic phosphorus acquisition and tuber yield of transgenic potato
Journal
Plant Molecular Biology
Journal Volume
67
Journal Issue
4
Pages
347-361
Date Issued
2008
Author(s)
Abstract
The sweet potato sporamin promoter was used to control the expression in transgenic potato of the E. coli appA gene, which encodes a bifunctional enzyme exhibiting both acid phosphatase and phytase activities. The sporamin promoter was highly active in leaves, stems and different size tubers of transgenic potato, with levels of phytase expression ranging from 3.8 to 7.4% of total soluble proteins. Phytase expression levels in transgenic potato tubers were stable over several cycles of propagation. Field tests showed that tuber size, number and yield increased in transgenic potato. Improved phosphorus (P) acquisition when phytate was provided as a sole P source and enhanced microtuber formation in cultured transgenic potato seedlings when phytate was provided as an additional P source were observed, which may account for the increase in leaf chloroplast accumulation (important for photosynthesis) and tuber yield of field-grown transgenic potato supplemented with organic fertilizers. Animal feeding tests indicated that the potato-produced phytase supplement was as effective as a commercially available microbial phytase in increasing the availability of phytate-P to weanling pigs. This study demonstrates that the sporamin promoter can effectively direct high-level recombinant protein expression in potato tubers. Moreover, overexpression of phytase in transgenic potato not only offers an ideal feed additive for improving phytate-P digestibility in monogastric animals but also improves tuber yield, enhances P acquisition from organic fertilizers, and has a potential for phytoremediation. © 2008 Springer Science+Business Media B.V.
Subjects
Feed additive; Phytase; Potato; Sporamin promoter; Sweet potato; Tuber yield and size
SDGs
Other Subjects
phosphorus; phytase; primer DNA; sporamin protein, Ipomoea batatas; vegetable protein; animal; article; bioavailability; enzymology; genetics; metabolism; nucleotide sequence; potato; promoter region; sweet potato; swine; transgenic plant; 6-Phytase; Animals; Base Sequence; Biological Availability; DNA Primers; Ipomoea batatas; Phosphorus; Plant Proteins; Plants, Genetically Modified; Promoter Regions (Genetics); Solanum tuberosum; Swine; Animalia; Escherichia coli; Ipomoea batatas; Solanum tuberosum; Suidae
Type
journal article