Temperature Inhibition of Carotene Synthesis in Tomato

• Published in: Botanical gazette (Chicago, Ill.) Ill.), 1963-03, Vol.124 (3), p.180-185
• Main Author: Tomes, Mark L.
• Format: Article
• Language: English
• Subjects: Biosynthesis; Carotenoids; Fruits; Genotypes; Hexanes; High temperature; Pigments; Polyenes; Temperature control; Tomatoes
• ISSN: 0006-8071
• DOI: 10.1086/336189

1. Seven different pigment strains of tomato were studied. In each type a number of excised fruits were matured at either 23.5⚬C. or 32.0⚬C. and the quantities of phytoene, phytofluene, α-carotene, β-carotene, ζ-carotene, ψ-carotene, prolycopene, δ-carotene, γ-carotene, neurosporene, and lycopene were determined. 2. With the exception of β-carotene and possibly prolycopene, production of all of the pigments and polyenes measured was reduced at 32⚬C. Some pigments appeared to be more sensitive to the higher temperature than others. Lycopene synthesis was drastically inhibited at 32⚬C. in every strain which produced this pigment. 3. Beta-carotene synthesis was not inhibited at 32⚬C. in the standard red tomato. When the pigments of this type were enhanced by the introduction of the high pigment factor (hp), the enlarged β-carotene fraction was not temperature sensitive. In the Tangerine type, where very little β-carotene is produced, no inhibition of its synthesis could be demonstrated. In these strains, β-carotene could hardly be synthesized from lycopene as has been postulated. 4. In strains which have enhanced β-carotene fractions resulting from the presence of either the gene B or the delta factor (Del), the increased synthesis of β-carotene was inhibited by maturation at 32⚬C. The evidence suggests that this β-carotene is synthesized by a different pathway than that of the standard red tomato.