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Increase in lysophosphatidate acyltransferase activity in oilseed rape ( Brassica napus ) increases seed triacylglycerol content despite its low intrinsic flux control coefficient
Author(s) -
Woodfield Helen K.,
Fenyk Stepan,
Wallington Emma,
Bates Ruth E.,
Brown Alexander,
Guschina Irina A.,
Marillia ElizabethFrance,
Taylor David C.,
Fell David,
Harwood John L.,
Fawcett Tony
Publication year - 2019
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.16100
Subject(s) - brassica , flux (metallurgy) , chemistry , context (archaeology) , acyltransferase , biochemistry , biophysics , food science , enzyme , botany , biology , paleontology , organic chemistry
Summary Lysophosphatidate acyltransferase ( LPAAT ) catalyses the second step of the Kennedy pathway for triacylglycerol ( TAG ) synthesis. In this study we expressed Trapaeolum majus LPAAT in Brassica napus ( B. napus ) cv 12075 to evaluate the effects on lipid synthesis and estimate the flux control coefficient for LPAAT . We estimated the flux control coefficient of LPAAT in a whole plant context by deriving a relationship between it and overall lipid accumulation, given that this process is a exponential. Increasing LPAAT activity resulted in greater TAG accumulation in seeds of between 25% and 29%; altered fatty acid distributions in seed lipids (particularly those of the Kennedy pathway); and a redistribution of label from 14 C‐glycerol between phosphoglycerides. Greater LPAAT activity in seeds led to an increase in TAG content despite its low intrinsic flux control coefficient on account of the exponential nature of lipid accumulation that amplifies the effect of the small flux increment achieved by increasing its activity. We have also developed a novel application of metabolic control analysis likely to have broad application as it determines the in planta flux control that a single component has upon accumulation of storage products.