AtROS1 overexpression provides evidence for epigenetic regulation of genes encoding enzymes of flavonoid biosynthesis and antioxidant pathways during salt stress in transgenic tobacco

Abstract Background Flavonoid biosynthesis in plants is primarily regulated at the transcriptional level by transcription factors modulating the expression of genes encoding enzymes in the flavonoid pathway. One of the most studied transcription factor complexes involved in this regulation consists of a MYB, bHLH and WD40. However, in Chinese Narcissus (Narcissus tazetta L. var. chinensis), a popular monocot bulb flower, the regulatory mechanism of flavonoid biosynthesis remains unclear. Results In this work, genes related to the regulatory complex, NtbHLH1 and a R2R3-MYB NtMYB6, were cloned from Chinese Narcissus. Phylogenetic analysis indicated that NtbHLH1 belongs to the JAF13 clade of bHLH IIIf subgroup, while NtMYB6 was highly homologous to positive regulators of proanthocyanidin biosynthesis. Both NtbHLH1 and NtMYB6 have highest expression levels in basal plates of Narcissus, where there is an accumulation of proanthocyanidin. Ectopic over expression of NtbHLH1 in tobacco resulted in an increase in anthocyanin accumulation in flowers, and an up-regulation of expression of the endogenous tobacco bHLH AN1 and flavonoid biosynthesis genes. In contrast, the expression level of LAR gene was significantly increased in NtMYB6-transgenic tobacco. Dual luciferase assays showed that co-infiltration of NtbHLH1 and NtMYB6 significantly activated the promoter of Chinese Narcissus DFR gene. Furthermore, a yeast two-hybrid assay confirmed that NtbHLH1 interacts with NtMYB6. Conclusions Our results suggest that NtbHLH1 may function as a regulatory partner by interacting directly with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus.

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Transcriptome Changes Reveal the Molecular Mechanisms of Humic Acid-Induced Salt Stress Tolerance in Arabidopsis

Molecules ◽

10.3390/molecules26040782 ◽

2021 ◽

Vol 26 (4) ◽

pp. 782

Author(s):

Joon-Yung Cha ◽

Sang-Ho Kang ◽

Myung Geun Ji ◽

Gyeong-Im Shin ◽

Song Yi Jeong ◽

...

Keyword(s):

Salt Stress ◽

Abiotic Stress ◽

Humic Acid ◽

Stress Tolerance ◽

Plant Development ◽

Molecular Mechanisms ◽

Abiotic Stress Tolerance ◽

Principal Component ◽

Salt Stress Tolerance ◽

Genes Encoding

Humic acid (HA) is a principal component of humic substances, which make up the complex organic matter that broadly exists in soil environments. HA promotes plant development as well as stress tolerance, however the precise molecular mechanism for these is little known. Here we conducted transcriptome analysis to elucidate the molecular mechanisms by which HA enhances salt stress tolerance. Gene Ontology Enrichment Analysis pointed to the involvement of diverse abiotic stress-related genes encoding HEAT-SHOCK PROTEINs and redox proteins, which were up-regulated by HA regardless of salt stress. Genes related to biotic stress and secondary metabolic process were mainly down-regulated by HA. In addition, HA up-regulated genes encoding transcription factors (TFs) involved in plant development as well as abiotic stress tolerance, and down-regulated TF genes involved in secondary metabolic processes. Our transcriptome information provided here provides molecular evidences and improves our understanding of how HA confers tolerance to salinity stress in plants.

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Down-Regulation of SlGRAS10 in Tomato Confers Abiotic Stress Tolerance

Genes ◽

10.3390/genes12050623 ◽

2021 ◽

Vol 12 (5) ◽

pp. 623

Author(s):

Sidra Habib ◽

Yee Yee Lwin ◽

Ning Li

Keyword(s):

Salt Stress ◽

Abiotic Stress ◽

Plant Growth ◽

Stress Tolerance ◽

Abiotic Stresses ◽

Abiotic Stress Tolerance ◽

Functional Characterization ◽

Flavonoid Biosynthesis ◽

Ros Scavenging ◽

Down Regulation

Adverse environmental factors like salt stress, drought, and extreme temperatures, cause damage to plant growth, development, and crop yield. GRAS transcription factors (TFs) have numerous functions in biological processes. Some studies have reported that the GRAS protein family plays significant functions in plant growth and development under abiotic stresses. In this study, we demonstrated the functional characterization of a tomato SlGRAS10 gene under abiotic stresses such as salt stress and drought. Down-regulation of SlGRAS10 by RNA interference (RNAi) produced dwarf plants with smaller leaves, internode lengths, and enhanced flavonoid accumulation. We studied the effects of abiotic stresses on RNAi and wild-type (WT) plants. Moreover, SlGRAS10-RNAi plants were more tolerant to abiotic stresses (salt, drought, and Abscisic acid) than the WT plants. Down-regulation of SlGRAS10 significantly enhanced the expressions of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) to reduce the effects of reactive oxygen species (ROS) such as O2− and H2O2. Malondialdehyde (MDA) and proline contents were remarkably high in SlGRAS10-RNAi plants. Furthermore, the expression levels of chlorophyll biosynthesis, flavonoid biosynthesis, and stress-related genes were also enhanced under abiotic stress conditions. Collectively, our conclusions emphasized the significant function of SlGRAS10 as a stress tolerate transcription factor in a certain variety of abiotic stress tolerance by enhancing osmotic potential, flavonoid biosynthesis, and ROS scavenging system in the tomato plant.

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Bisphenol A-associated alterations in the expression and epigenetic regulation of genes encoding xenobiotic metabolizing enzymes in human fetal liver

Environmental and Molecular Mutagenesis ◽

10.1002/em.21823 ◽

2013 ◽

Vol 55 (3) ◽

pp. 184-195 ◽

Cited By ~ 35

Author(s):

Muna S. Nahar ◽

Jung H. Kim ◽

Maureen A. Sartor ◽

Dana C. Dolinoy

Keyword(s):

Bisphenol A ◽

Epigenetic Regulation ◽

Fetal Liver ◽

Metabolizing Enzymes ◽

Human Fetal Liver ◽

Xenobiotic Metabolizing Enzymes ◽

Genes Encoding

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Over-Expression of AtEXPB2 Alleviates Salt Stress Damage in Transgenic Tobacco Plants

Russian Journal of Plant Physiology ◽

10.1134/s1021443721020035 ◽

2021 ◽

Vol 68 (2) ◽

pp. 274-285

Author(s):

M. Chalekaei ◽

A. Abbasi ◽

S. Yousefi ◽

D. Dadashi

Keyword(s):

Salt Stress ◽

Transgenic Tobacco ◽

Transgenic Tobacco Plants ◽

Tobacco Plants ◽

Over Expression ◽

Stress Damage

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Overexpression of WAX INDUCER1/SHINE1 Gene Enhances Wax Accumulation under Osmotic Stress and Oil Synthesis in Brassica napus

International Journal of Molecular Sciences ◽

10.3390/ijms20184435 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4435 ◽

Cited By ~ 3

Author(s):

Ning Liu ◽

Jie Chen ◽

Tiehu Wang ◽

Qing Li ◽

Pengpeng Cui ◽

...

Keyword(s):

Salt Stress ◽

Brassica Napus ◽

De Novo ◽

Normal Growth ◽

Acid Synthesis ◽

Growth Conditions ◽

Lipid Profiling ◽

Intracellular Lipids ◽

Oil Synthesis ◽

Genes Encoding

WAX INDUCER1/SHINE1 (WIN1) belongs to the AP2/EREBP transcription factor family and plays an important role in wax and cutin accumulation in plants. Here we show that BnWIN1 from Brassica napus (Bn) has dual functions in wax accumulation and oil synthesis. Overexpression (OE) of BnWIN1 led to enhanced wax accumulation and promoted growth without adverse effects on oil synthesis under salt stress conditions. Lipid profiling revealed that BnWIN1-OE plants accumulated more waxes with elevated C29-alkanes, C31-alkanes, C28-alcohol, and C29-alcohol relative to wild type (WT) under salt stress. Moreover, overexpression of BnWIN1 also increased seed oil content under normal growth conditions. BnWIN1 directly bound to the promoter region of genes encoding biotin carboxyl carrier protein 1 (BCCP1), glycerol-3-phosphate acyltransferase 9 (GPAT9), lysophosphatidic acid acyltransferase 5 (LPAT5), and diacylglycerol acyltransferase 2 (DGAT2) involved in the lipid anabolic process. Overexpression of BnWIN1 resulted in upregulated expression of numerous genes involved in de novo fatty acid synthesis, wax accumulation, and oil production. The results suggest that BnWIN1 is a transcriptional activator to regulate the biosynthesis of both extracellular and intracellular lipids.

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A forty-year journey in plant research: original contributions to flavonoid biochemistry

Canadian Journal of Botany ◽

10.1139/b05-030 ◽

2005 ◽

Vol 83 (5) ◽

pp. 433-450 ◽

Cited By ~ 18

Author(s):

Ragai K Ibrahim

Keyword(s):

Three Dimensional ◽

Biological Significance ◽

Flavonoid Biosynthesis ◽

Dimensional Structure ◽

Enzymatic Reactions ◽

Research Career ◽

Substrate Preferences ◽

Genes Encoding ◽

The Common ◽

New Compounds

This review highlights original contributions by the author to the field of flavonoid biochemistry during his research career of more than four decades. These include elucidation of novel aspects of some of the common enzymatic reactions involved in the later steps of flavonoid biosynthesis, with emphasis on methyltransferases, glucosyltransferases, sulfotransferases, and an oxoglutarate-dependent dioxygenase, as well as cloning, and inferences about phylogenetic relationships, of the genes encoding some of these enzymes. The three-dimensional structure of a flavonol O-methyltransferase was studied through homology-based modeling, using a caffeic acid O-methyltransferase as a template, to explain their strict substrate preferences. In addition, the biological significance of enzymatic prenylation of isoflavones, as well as their role as phytoanticipins and inducers of nodulation genes, are emphasized. Finally, the potential application of knowledge about the genes encoding these enzyme reactions is discussed in terms of improving plant productivity and survival, modification of flavonoid profiles, and the search for new compounds with pharmaceutical and (or) nutraceutical value.Key words: flavonoid enzymology, metabolite localization, gene cloning, 3-D structure, phylogeny.

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Overexpression of SlMDHAR in transgenic tobacco increased salt stress tolerance involving S-nitrosylation regulation

Plant Science ◽

10.1016/j.plantsci.2020.110609 ◽

2020 ◽

Vol 299 ◽

pp. 110609 ◽

Cited By ~ 1

Author(s):

Qi Qi ◽

Dong Yanyan ◽

Liang Yuanlin ◽

Li Kunzhi ◽

Xu Huini ◽

...

Keyword(s):

Salt Stress ◽

Stress Tolerance ◽

Transgenic Tobacco ◽

Salt Stress Tolerance

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The Effect of Light Intensity on the Expression of Leucoanthocyanidin Reductase in Grapevine Calluses and Analysis of Its Promoter Activity

Genes ◽

10.3390/genes11101156 ◽

2020 ◽

Vol 11 (10) ◽

pp. 1156

Author(s):

Jing Cheng ◽

Keji Yu ◽

Mingyue Zhang ◽

Ying Shi ◽

Changqing Duan ◽

...

Keyword(s):

Light Intensity ◽

Promoter Activity ◽

Flavonoid Biosynthesis ◽

Response Patterns ◽

Flavonoid Pathway ◽

Leucoanthocyanidin Reductase ◽

Genes Encoding ◽

Intensity Changes ◽

Different Response ◽

Effect Of Light

To investigate the effect of light intensity on flavonoid biosynthesis, grapevine calluses were subjected to high light (HL, 250 μmol m−2 s−1) and dark (0 μmol m−2 s−1) in comparison to 125 μmol m−2 s−1 under controlled conditions (NL). The alteration of flavonoid profiles was determined and was integrated with RNA sequencing (RNA-seq)-based transcriptional changes of the flavonoid pathway genes. Results revealed that dark conditions inhibited flavonoid biosynthesis. Increasing light intensity affected flavonoids differently—the concentrations of flavonols and anthocyanins as well as the expressions of corresponding genes were less affected, whereas flavan-3-ol concentrations were predominantly increased, which caused enhanced trans-flavan-3-ol concentrations. Moreover, genes encoding leucoanthocyanidin reductase (LAR) exhibited different response patterns to light intensity changes—VviLAR1 expression increased with an increased light intensity, whereas VviLAR2 expression was insensitive. We further confirmed that the known transcription factors (TFs) involved in regulating flavan-3-ol biosynthesis utilized VviLAR1 as a target gene in grapevine calluses. In addition, VviLAR1 promoter activity was more sensitive to light intensity changes than that of VviLAR2 as determined using a transgenic Arabidopsis leaf system. These results suggested that light intensity had the most prominent effect on trans-flavan-3-ols in grapevine calluses and demonstrated that the two LAR genes had different response patterns to light intensity changes.

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