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Temperature effects upon the expression of a high oleic acid trait in soybean
Author(s) -
Martin B. A.,
Wilson R. F.,
Rinne R. W.
Publication year - 1986
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02546044
Subject(s) - germplasm , linoleic acid , linolenic acid , oleic acid , biology , fatty acid , botany , horticulture , composition (language) , zoology , food science , biochemistry , linguistics , philosophy
Soybeans ( Glycine max L. Merr. cvs. N78‐2245 and Dare) were grown to maturity under controlled environments to investigate temperature effects upon the fatty acid composition of developing seed. These genotypes exhibited genetic differences in oleic acid (18:1) content. Mature seed from N78‐2245 germplasm normally contained ca. 43 mol% 18:1, and Dare seed contained ca. 18 mol% 18:1. When grown at 30/26 C or 22/18 C, the overall response of these genotypes to temperature resulted in lower 18:1 and higher linoleic (18:2) and linolenic (18:3) acid concentrations in mature seed. However, the genotypic response was much more pronounced in N78‐2245 seed than in Dare seed. The basis for these genotypic differences appeared to be related to temperature effects upon the differentiation of the 18:1‐synthetic and 18:1‐desaturation mechanisms during seed development. Although the high‐18:1 trait was expressed during N78‐2245 seed development at both temperatures, high‐18:1 glycerolipids accumulated during a shorter developmental period at 22/18 C than at 30/26 C. At 30/26 C, glycerolipids containing greater than 50% 18:1 were deposited between 20 and 45 days after flowering (DAF) and accounted for 84% (w/w) of the oil in mature seed. At 22/18 C, glycerolipids with similar fatty acid composition were formed between 30 and 45 DAF and accounted for only 40% (w/w) of the oil. Temperature effects upon 18:1‐desaturation also appeared to mediate the overall differences in unsaturated fatty acid composition in these genotypes. The 18:1‐desaturation mechanism in N78‐2245 seed was more sensitive to temperature than that in Dare seed. These genotype‐treatment combinations were ranked by degree of 18:1‐desaturation in the order: Dare (22/18 C) = Dare (30/26 C) ≥ N78‐2245 (22/18 C) > N78‐2245 (30/26 C). It was proposed that the ranking of these genotype‐treatment combinations may be attributed, in part, to the tissue levels of the 18:1‐desaturase enzymes in soybean seed grown at different temperatures.