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Zhang L, Wu P, Li W, Feng T, Shockey J, Chen L, Zhang L, Lü S. Triacylglycerol biosynthesis in shaded seeds of tung tree (Vernicia fordii) is regulated in part by Homeodomain Leucine Zipper 21. Plant J 2021; 108:1735-1753. [PMID: 34643970 DOI: 10.1111/tpj.15540] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Light quantity and quality affect many aspects of plant growth and development. However, few reports have addressed the molecular connections between seed oil accumulation and light conditions, especially dense shade. Shade-avoiding plants can redirect plant resources into extension growth at the expense of leaf and root expansion in an attempt to reach areas containing richer light. Here, we report that tung tree seed oil accumulation is suppressed by dense shade during the rapid oil accumulation phase. Transcriptome analysis confirmed that oil accumulation suppression due to dense shade was attributed to reduced expression of fatty acid and triacylglycerol biosynthesis-related genes. Through weighted gene co-expression network analysis, we identified 32 core transcription factors (TFs) specifically upregulated in densely shaded seeds during the rapid oil accumulation period. Among these, VfHB21, a class I homeodomain leucine zipper TF, was shown to suppress expression of FAD2 and FADX, two key genes related to α-eleostearic acid, by directly binding to HD-ZIP I/II motifs in their respective promoter regions. VfHB21 also binds to similar motifs in the promoters of VfWRI1 and VfDGAT2, two additional key seed lipid regulatory/biosynthetic genes. Functional conservation of HB21 during plant evolution was demonstrated by the fact that AtWRI1, AtSAD1, and AtFAD2 were downregulated in VfHB21-overexpressor lines of transgenic Arabidopsis, with concomitant seed oil reduction, and the fact that AtHB21 expression also was induced by shade. This study reveals some of the regulatory mechanisms that specifically control tung tree seed oil biosynthesis and more broadly regulate plant storage carbon partitioning in response to dense shade conditions.
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Affiliation(s)
- Lingling Zhang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, 430074, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Pan Wu
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, 430074, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Wenying Li
- Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, 410004, China
| | - Tao Feng
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Jay Shockey
- United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA
| | - Liang Chen
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, 430074, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Lin Zhang
- Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, 410004, China
| | - Shiyou Lü
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
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Aruna P, Venkataramanamma D, Singh AK, Singh RP. Health Benefits of Punicic Acid: A Review. Compr Rev Food Sci Food Saf 2015; 15:16-27. [PMID: 33371578 DOI: 10.1111/1541-4337.12171] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/21/2015] [Accepted: 08/22/2015] [Indexed: 12/13/2022]
Abstract
Punicic acid (PA) is a polyunsaturated fatty acid (18:3 n-5), which is classified as a conjugated linolenic acid. PA is also referred as a "super CLnA" whose effect is even more potent than that of an ordinary CLnA. It is found mainly in the seeds of pomegranate fruit (Punica granatum) and Trichoxanthes kirilowii and some other minor sources. It possesses a wide array of biological properties including antidiabetic, antiobesity, antiproliferative, and anticarcinogenic activity against various forms of cancer. In spite of this, PA has not been explored as a nutraceutical or as an ingredient of food products which can be aimed at specific consumer target groups. This review details the various health-beneficial properties of PA and explores the possibilities of its utilization as an active ingredient in various food products.
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Affiliation(s)
- P Aruna
- Academy of Scientific and Innovative Research (AcSIR), Taramani, Chennai, Tamil Nadu, India.,the Dept. of Biochemistry and Nutrition, CSIR-Central Food Technological Research Inst, Mysore 570020, Karnataka, India
| | - D Venkataramanamma
- Academy of Scientific and Innovative Research (AcSIR), Taramani, Chennai, Tamil Nadu, India.,the Dept. of Biochemistry and Nutrition, CSIR-Central Food Technological Research Inst, Mysore 570020, Karnataka, India
| | - Alok Kumar Singh
- the Dept. of Biochemistry and Nutrition, CSIR-Central Food Technological Research Inst, Mysore 570020, Karnataka, India
| | - R P Singh
- Academy of Scientific and Innovative Research (AcSIR), Taramani, Chennai, Tamil Nadu, India.,the Dept. of Biochemistry and Nutrition, CSIR-Central Food Technological Research Inst, Mysore 570020, Karnataka, India
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Obitsu S, Sakata K, Teshima R, Kondo K. Eleostearic acid induces RIP1-mediated atypical apoptosis in a kinase-independent manner via ERK phosphorylation, ROS generation and mitochondrial dysfunction. Cell Death Dis 2013; 4:e674. [PMID: 23788031 PMCID: PMC3702295 DOI: 10.1038/cddis.2013.188] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 04/30/2013] [Accepted: 04/30/2013] [Indexed: 01/26/2023]
Abstract
RIP1 is a serine/threonine kinase, which is involved in apoptosis and necroptosis. In apoptosis, caspase-8 and FADD have an important role. On the other hand, RIP3 is a key molecule in necroptosis. Recently, we reported that eleostearic acid (ESA) elicits caspase-3- and PARP-1-independent cell death, although ESA-treated cells mediate typical apoptotic morphology such as chromatin condensation, plasma membrane blebbing and apoptotic body formation. The activation of caspases, Bax and PARP-1, the cleavage of AIF and the phosphorylation of histone H2AX, all of which are characteristics of typical apoptosis, do not occur in ESA-treated cells. However, the underlying mechanism remains unclear. To clarify the signaling pathways in ESA-mediated apoptosis, we investigated the functions of RIP1, MEK, ERK, as well as AIF. Using an extensive study based on molecular biology, we identified the alternative role of RIP1 in ESA-mediated apoptosis. ESA mediates RIP1-dependent apoptosis in a kinase independent manner. ESA activates serine/threonine phosphatases such as calcineurin, which induces RIP1 dephosphorylation, thereby ERK pathway is activated. Consequently, localization of AIF and ERK in the nucleus, ROS generation and ATP reduction in mitochondria are induced to disrupt mitochondrial cristae, which leads to cell death. Necrostatin (Nec)-1 blocked MEK/ERK phosphorylation and ESA-mediated apoptosis. Nec-1 inactive form (Nec1i) also impaired ESA-mediated apoptosis. Nec1 blocked the interaction of MEK with ERK upon ESA stimulation. Together, these findings provide a new finding that ERK and kinase-independent RIP1 proteins are implicated in atypical ESA-mediated apoptosis.
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Affiliation(s)
- S Obitsu
- Division of Novel Foods and Immunochemistry, National Institute of Health Sciences, Tokyo, Japan
| | - K Sakata
- Division of Novel Foods and Immunochemistry, National Institute of Health Sciences, Tokyo, Japan
| | - R Teshima
- Division of Novel Foods and Immunochemistry, National Institute of Health Sciences, Tokyo, Japan
| | - K Kondo
- Division of Novel Foods and Immunochemistry, National Institute of Health Sciences, Tokyo, Japan
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Kondo K, Obitsu S, Ohta S, Matsunami K, Otsuka H, Teshima R. Poly(ADP-ribose) polymerase (PARP)-1-independent apoptosis-inducing factor (AIF) release and cell death are induced by eleostearic acid and blocked by alpha-tocopherol and MEK inhibition. J Biol Chem 2010; 285:13079-91. [PMID: 20177052 PMCID: PMC2857103 DOI: 10.1074/jbc.m109.044206] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 02/02/2010] [Indexed: 11/06/2022] Open
Abstract
Poly(ADP-ribose)polymerase-1 (PARP-1) is thought to be required for apoptosis-inducing factor (AIF) release from mitochondria in caspase-independent apoptosis. The mechanism by which AIF is released through PARP-1 remains unclear. Here, we provide evidence that PARP-1-independent AIF release and cell death are induced by a trienoic fatty acid, alpha-eleostearic acid (alpha-ESA). Alpha-ESA induced the caspase-independent and AIF-initiated apoptotic death of neuronal cell lines, independently of PARP-1 activation. The cell death was inhibited by the MEK inhibitor U0126 and by knockdown of MEK using small interfering RNA. However, inhibitors for JNK, p38 inhibitors, calpain, phospholipase A(2), and phosphatidylinositol 3-kinase, did not block cell death. AIF was translocated to the nucleus after the induction of apoptosis by alpha-ESA in differentiated PC12 cells without activating caspase-3 and PARP-1. The alpha-ESA-mediated cell death was not inhibited by PARP inhibitor 3,4-dihydro-5-[4-(1-piperidinyl)butoxyl]-1(2H)-isoquinoline and by knockdown of PARP-1 using small interfering RNA. Unlike N-methyl-N'-nitro-N-nitrosoguanidine treatment, histone-phosphorylated histone 2AX was not phosphorylated by alpha-ESA, which suggests no DNA damage. Overexpression of Bcl-2 did not inhibit the cell death. alpha-ESA caused a small quantity of superoxide production in the mitochondria, resulting in the reduction of mitochondrial membrane potential, both of which were blocked by a trace amount of alpha-tocopherol localized in the mitochondria. Our results demonstrate that alpha-ESA induces PARP-1-independent AIF release and cell death without activating Bax, cytochrome c, and caspase-3. MEK is also a key molecule, although the link between ERK, AIF release, and cell death remains unknown. Finding molecules that regulate AIF release may be an important therapeutic target for the treatment of neuronal injury.
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Affiliation(s)
- Kazunari Kondo
- Division of Novel Food and Immunochemistry, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya, Tokyo 158-8501, Japan.
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