Transgenic soya bean seeds accumulating β-carotene exhibit the collateral enhancements of oleate and protein content traits.
Transgenic soya bean (Glycine max) plants overexpressing a seed-specific bacterial phytoene synthase gene from Pantoea ananatis modified to target to plastids accumulated 845 μg β carotene g(-1) dry seed weight with a desirable 12:1 ratio of β to α. The β carotene accumulating seeds exhibited a shift in oil composition increasing oleic acid with a concomitant decrease in linoleic acid and an increase in seed protein content by at least 4% (w/w). Elevated β-carotene accumulating soya bean cotyledons contain 40% the amount of abscisic acid compared to nontransgenic cotyledons. Proteomic and nontargeted metabolomic analysis of the mid-maturation β-carotene cotyledons compared to the nontransgenic did not reveal any significant differences that would account for the altered phenotypes of both elevated oleate and protein content. Transcriptomic analysis, confirmed by RT-PCR, revealed a number of significant differences in ABA-responsive transcripton factor gene expression in the crtB transgenics compared to nontransgenic cotyledons of the same maturation stage. The altered seed composition traits seem to be attributed to altered ABA hormone levels varying transcription factor expression. The elevated β-carotene, oleic acid and protein traits in the β-carotene soya beans confer a substantial additive nutritional quality to soya beans.
School of Plant Sciences/BIO5 Institute, University of Arizona, Tucson, AZ, USA.
Monica A
MA
Schmidt
Wayne A
WA
Parrott
David F
DF
Hildebrand
R Howard
RH
Berg
Amanda
A
Cooksey
Ken
K
Pendarvis
Yonghua
Y
He
Fiona
F
McCarthy
Eliot M
EM
Herman
D000040:Abscisic Acid / Q000378:metabolism; D002338:Carotenoids / Q000096:biosynthesis; D044943:Fatty Acid Desaturases / Q000235:genetics; D020869:Gene Expression Profiling; D019301:Oleic Acid / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012639:Seeds / Q000378:metabolism*; D013025:Glycine max / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D019207:beta Carotene / Q000378:metabolism*
D010940:Plant Proteins; D019207:beta Carotene; D019301:Oleic Acid; D002338:Carotenoids; D000040:Abscisic Acid; D044943:Fatty Acid Desaturases
carotenoid; elevated protein; oleic acid; seed; soybean