To gain insight into the genetic regulation of lipid metabolism in tomato, we conducted metabolic trait loci （mQTL） analysis following the lipidomic profiling of fruit pericarp and leaf tissue of the Solanum pennell...To gain insight into the genetic regulation of lipid metabolism in tomato, we conducted metabolic trait loci （mQTL） analysis following the lipidomic profiling of fruit pericarp and leaf tissue of the Solanum pennellii introgression lines （IL）. To enhance mapping resolution for selected fruit-specific mQTL, we profiled the lipids in a subset of independently derived S. pennellii backcross inbred lines, as well as in a nearsogenic sub-iL population. We identified a putative lecithin：cholesterol acyltransferase that controls the levels of several lipids, and two members of the class III lipase family, LIP1 and LIP2, that were associated with decreased levels of diacylglycerols （DAGs） and triacylglycerols （TAGs）. Lipases of this class cleave fatty acids from the glycerol backbone of acylglycerols. The released fatty acids serve as precursors of flavor volatiles. We show that LIP1 expression correlates with fatty acid-derived volatile levels. We further confirm the function of LIP1 in TAG and DAG breakdown and volatile synthesis using transgenic plants. Taken together, our study extensively characterized the genetic architecture of Upophilic compounds in tomato and demonstrated at molecular level that release of free fatty acids from the glycerol backbone can have a major impact on downstream volatile synthesis.展开更多
基金Part of this work was also supported by a grant from the National Science Foundation （IOS-0923312） to H.K.S.A. and A.R.F. acknowledge funding of the PlantaSYST project by the European Union＇s Horizon 2020 research and innovation program （SGA-CSA nos. 664621 and 739582 under FPA no. 664620）. D.Z. was funded by a TOMRES grant （142020 #727929）.
文摘To gain insight into the genetic regulation of lipid metabolism in tomato, we conducted metabolic trait loci （mQTL） analysis following the lipidomic profiling of fruit pericarp and leaf tissue of the Solanum pennellii introgression lines （IL）. To enhance mapping resolution for selected fruit-specific mQTL, we profiled the lipids in a subset of independently derived S. pennellii backcross inbred lines, as well as in a nearsogenic sub-iL population. We identified a putative lecithin：cholesterol acyltransferase that controls the levels of several lipids, and two members of the class III lipase family, LIP1 and LIP2, that were associated with decreased levels of diacylglycerols （DAGs） and triacylglycerols （TAGs）. Lipases of this class cleave fatty acids from the glycerol backbone of acylglycerols. The released fatty acids serve as precursors of flavor volatiles. We show that LIP1 expression correlates with fatty acid-derived volatile levels. We further confirm the function of LIP1 in TAG and DAG breakdown and volatile synthesis using transgenic plants. Taken together, our study extensively characterized the genetic architecture of Upophilic compounds in tomato and demonstrated at molecular level that release of free fatty acids from the glycerol backbone can have a major impact on downstream volatile synthesis.
