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Phospholipid:diacylglycerol acyltransferase‐mediated triacylglycerol biosynthesis is crucial for protection against fatty acid‐induced cell death in growing tissues of A rabidopsis
Author(s) -
Fan Jilian,
Yan Chengshi,
Xu Changcheng
Publication year - 2013
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12343
Subject(s) - diacylglycerol kinase , acyltransferase , biology , phospholipid , biochemistry , mutant , fatty acid , microbiology and biotechnology , biosynthesis , gene , enzyme , protein kinase c , membrane
Summary Phospholipid:diacylglycerol acyltransferase ( PDAT ) and diacylglycerol:acyl C o A acyltransferase play overlapping roles in triacylglycerol ( TAG ) assembly in A rabidopsis, and are essential for seed and pollen development, but the functional importance of PDAT in vegetative tissues remains largely unknown. Taking advantage of the A rabidopsis tgd1–1 mutant that accumulates oil in vegetative tissues, we demonstrate here that PDAT 1 is crucial for TAG biosynthesis in growing tissues. We show that disruption of PDAT 1 in the tgd1–1 mutant background causes serious growth retardation, gametophytic defects and premature cell death in developing leaves. Lipid analysis data indicated that knockout of PDAT 1 results in increases in the levels of free fatty acids ( FFA s) and diacylglycerol. In vivo 14 C ‐acetate labeling experiments showed that, compared with wild‐type, tgd1–1 exhibits a 3.8‐fold higher rate of fatty acid synthesis ( FAS ), which is unaffected by disruption or over‐expression of PDAT 1 , indicating a lack of feedback regulation of FAS in tgd1–1 . We also show that detached leaves of both pdat1–2 and tgd1–1 pdat1–2 display increased sensitivity to FFA but not to diacylglycerol. Taken together, our results reveal a critical role for PDAT 1 in mediating TAG synthesis and thereby protecting against FFA ‐induced cell death in fast‐growing tissues of plants.