Loss-of-function mutations in novel triacylglycerol lipase genes are associated with low rancidity in pearl millet flour

Abstract

ABSTRACTCommercialization and utilization of pearl millet (Pennisetum glaucum L.) by consumers and processing industry is constrained due to rapid onset of rancidity in its milled flour. We studied the underlying biochemical and molecular mechanisms to flour rancidity in contrasting inbreds under 21-day accelerated storage. Rapid TAG decrease was accompanied by FFA increase in high rancidity genotype compared to the low rancidity line, that maintained lower FFA and high TAG levels, besides lower headspace aldehydes. DNA sequence polymorphisms observed in two lipase genes revealed loss-of-function mutations that were functionally confirmed in yeast system. We outline a direct mechanism for mutations in these key TAG lipases in pearl millet and the protection of TAG and fatty acids from hydrolytic and oxidative rancidity respectively,. Natural variation in the PgTAGLip1 and PgTAGLip2 genes may be selected through marker assisted breeding or by precision genetics methods to develop hybrids with improved flour shelf life.