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DIACYLGLYCEROL ACYLTRANSFERASE and DIACYLGLYCEROL KINASE Modulate Triacylglycerol and Phosphatidic Acid Production in the Plant Response to Freezing Stress
- Source :
- Plant Physiology. 177:1303-1318
- Publication Year :
- 2018
- Publisher :
- Oxford University Press (OUP), 2018.
-
Abstract
- Plants accumulate the lipids phosphatidic acid (PA), diacylglycerol (DAG), and triacylglycerol (TAG) during cold stress, but how plants balance the levels of these lipids to mediate cold responses remains unknown. The enzymes ACYL-COENZYME A:DIACYLGLYCEROL ACYLTRANSFERASE (DGAT) and DIACYLGLYCEROL KINASE (DGK) catalyze the conversion of DAG to TAG and PA, respectively. Here, we show that DGAT1, DGK2, DGK3, and DGK5 contribute to the response to cold in Arabidopsis (Arabidopsis thaliana). With or without cold acclimation, the dgat1 mutants exhibited higher sensitivity upon freezing exposure compared with the wild type. Under cold conditions, the dgat1 mutants showed reduced expression of C-REPEAT/DRE BINDING FACTOR2 and its regulons, which are essential for the acquisition of cold tolerance. Lipid profiling revealed that freezing significantly increased the levels of PA and DAG while decreasing TAG in the rosettes of dgat1 mutant plants. During freezing stress, the accumulation of PA in dgat1 plants stimulated NADPH oxidase activity and enhanced RbohD-dependent hydrogen peroxide production compared with the wild type. Moreover, the cold-inducible transcripts of DGK2, DGK3, and DGK5 were significantly more up-regulated in the dgat1 mutants than in the wild type during cold stress. Consistent with this observation, dgk2, dgk3, and dgk5 knockout mutants showed improved tolerance and attenuated PA production in response to freezing temperatures. Our findings demonstrate that the conversion of DAG to TAG by DGAT1 is critical for plant freezing tolerance, acting by balancing TAG and PA production in Arabidopsis.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Diacylglycerol Kinase
Physiology
Mutant
Arabidopsis
Phosphatidic Acids
Plant Science
Corrections
01 natural sciences
Diglycerides
Gene Knockout Techniques
03 medical and health sciences
chemistry.chemical_compound
Gene Expression Regulation, Plant
Freezing
Genetics
Cold acclimation
Arabidopsis thaliana
Diacylglycerol O-Acyltransferase
Triglycerides
Diacylglycerol kinase
chemistry.chemical_classification
biology
Arabidopsis Proteins
Cold-Shock Response
Wild type
NADPH Oxidases
Hydrogen Peroxide
Phosphatidic acid
biology.organism_classification
030104 developmental biology
Enzyme
Biochemistry
chemistry
Mutation
Trans-Activators
lipids (amino acids, peptides, and proteins)
Salicylic Acid
010606 plant biology & botany
Subjects
Details
- ISSN :
- 15322548 and 00320889
- Volume :
- 177
- Database :
- OpenAIRE
- Journal :
- Plant Physiology
- Accession number :
- edsair.doi.dedup.....7aac027096698690ac89b5c3d0975e7a