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Khedr EH, Khedr N. Enhancing productivity, modifying biochemical parameters, and regulating the phenylpropanoid pathway in 'Le-Conte' pears through optimal protocatechuic acid treatments. BMC PLANT BIOLOGY 2024; 24:50. [PMID: 38221634 PMCID: PMC10789004 DOI: 10.1186/s12870-023-04715-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/29/2023] [Indexed: 01/16/2024]
Abstract
BACKGROUND This study aimed to investigate the impact of protocatechuic acid (PRC) treatments on the productivity and fruit quality of 'Le-Conte' pears, with a specific focus on productivity, stone cells content, and antioxidant activity. The research spanned over three consecutive cultivating seasons, with the first season serving as a preliminary study to determine the optimal PRC concentrations and the most effective number of spray applications. During the initial season, response surface methodology (RSM) was employed to optimize PRC concentration and application frequency. PRC was evaluated at concentrations ranging from 50 to 400 ppm, with treatment frequencies of either once or twice. Considering the optimal conditions obtained from RSM results, PRC treatments at 200 ppm and 300 ppm were applied twice, and their respective effects were studied in comparison to the control in the following seasons. RESULTS RSM results indicated that PRC at 200 and 300 ppm, applied twice, once during full bloom and again three weeks later, yielded the most significant effects. Subsequent studies revealed that PRC treatments had a substantial impact on various aspects of fruit production and quality. Applying 300 ppm PRC once during full bloom and again three weeks later resulted in higher fruit set percentages, lower fruit abscission, and enhanced fruit yield compared to untreated trees. Additionally, the 200 ppm PRC treatment maintained physicochemical characteristics such as fruit color, increased total soluble solids (TSS), and total sugar, and maintained higher ascorbic acid content and antioxidant capacity in the fruits while reducing stone cells content and lignin. Notably, enzyme activities related to phenylpropanoid metabolism and stone cells, including phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-Coumarate-CoA Ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), and cinnamoyl-CoA reductase (CCR), as well as peroxidase, polyphenol oxidase, and laccase, were significantly regulated by PRC treatments. CONCLUSION Overall, this study suggests that PRC treatments are suitable for enhancing pear yield and quality, with PRC at 200 ppm being the more recommended option over 300 ppm. This approach serves as an effective strategy for achieving a balance between enhancing the productivity and fruit quality of 'Le-Conte' pears.
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Affiliation(s)
- Emad Hamdy Khedr
- Department of Pomology, Faculty of Agriculture, Cairo University, Giza, 12613, Egypt.
| | - Nagwa Khedr
- Department of Pomology, Faculty of Agriculture, Cairo University, Giza, 12613, Egypt
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De Meester B, Madariaga Calderón B, de Vries L, Pollier J, Goeminne G, Van Doorsselaere J, Chen M, Ralph J, Vanholme R, Boerjan W. Tailoring poplar lignin without yield penalty by combining a null and haploinsufficient CINNAMOYL-CoA REDUCTASE2 allele. Nat Commun 2020; 11:5020. [PMID: 33024118 PMCID: PMC7538556 DOI: 10.1038/s41467-020-18822-w] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 09/16/2020] [Indexed: 01/09/2023] Open
Abstract
Lignin causes lignocellulosic biomass recalcitrance to enzymatic hydrolysis. Engineered low-lignin plants have reduced recalcitrance but often exhibit yield penalties, offsetting their gains in fermentable sugar yield. Here, CRISPR/Cas9-generated CCR2(−/*) line 12 poplars have one knockout CCR2 allele while the other contains a 3-bp deletion, resulting in a 114I115A-to-114T conversion in the corresponding protein. Despite having 10% less lignin, CCR2(−/*) line 12 grows normally. On a plant basis, the saccharification efficiency of CCR2(−/*) line 12 is increased by 25–41%, depending on the pretreatment. Analysis of monoallelic CCR2 knockout lines shows that the reduced lignin amount in CCR2(−/*) line 12 is due to the combination of a null and the specific haploinsufficient CCR2 allele. Analysis of another CCR2(−/*) line shows that depending on the specific CCR2 amino-acid change, lignin amount and growth can be affected to different extents. Our findings open up new possibilities for stably fine-tuning residual gene function in planta. Plants with reduced amounts of lignin typically suffer from dwarfed growth, which offsets their gain in fermentable sugar yield. Here, the authors show that genome-edited poplar lines with a null and a haploinsufficient allele of CINNAMOYL-COA REDUCTASE2 (CCR2) can be obtained that have a reduced lignin level and normal growth.
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Affiliation(s)
- Barbara De Meester
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052, Ghent, Belgium.,VIB Center for Plant Systems Biology, Technologiepark 71, 9052, Ghent, Belgium
| | - Barbara Madariaga Calderón
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052, Ghent, Belgium.,VIB Center for Plant Systems Biology, Technologiepark 71, 9052, Ghent, Belgium
| | - Lisanne de Vries
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052, Ghent, Belgium.,VIB Center for Plant Systems Biology, Technologiepark 71, 9052, Ghent, Belgium
| | - Jacob Pollier
- VIB Metabolomics Core, Technologiepark 71, 9052, Ghent, Belgium
| | - Geert Goeminne
- VIB Metabolomics Core, Technologiepark 71, 9052, Ghent, Belgium
| | - Jan Van Doorsselaere
- Higher Institute for Nursing and Biotechnology, VIVES University College, Wilgenstraat 32, 8800, Roeselare, Belgium
| | - Mingjie Chen
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.,US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, WI, 53726, USA
| | - John Ralph
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.,US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, WI, 53726, USA
| | - Ruben Vanholme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052, Ghent, Belgium.,VIB Center for Plant Systems Biology, Technologiepark 71, 9052, Ghent, Belgium
| | - Wout Boerjan
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052, Ghent, Belgium. .,VIB Center for Plant Systems Biology, Technologiepark 71, 9052, Ghent, Belgium.
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Pan H, Zhou R, Louie GV, Mühlemann JK, Bomati EK, Bowman ME, Dudareva N, Dixon RA, Noel JP, Wang X. Structural studies of cinnamoyl-CoA reductase and cinnamyl-alcohol dehydrogenase, key enzymes of monolignol biosynthesis. THE PLANT CELL 2014; 26:3709-27. [PMID: 25217505 PMCID: PMC4213152 DOI: 10.1105/tpc.114.127399] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/27/2014] [Accepted: 08/08/2014] [Indexed: 05/18/2023]
Abstract
The enzymes cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the two key reduction reactions in the conversion of cinnamic acid derivatives into monolignol building blocks for lignin polymers in plant cell walls. Here, we describe detailed functional and structural analyses of CCRs from Medicago truncatula and Petunia hybrida and of an atypical CAD (CAD2) from M. truncatula. These enzymes are closely related members of the short-chain dehydrogenase/reductase (SDR) superfamily. Our structural studies support a reaction mechanism involving a canonical SDR catalytic triad in both CCR and CAD2 and an important role for an auxiliary cysteine unique to CCR. Site-directed mutants of CAD2 (Phe226Ala and Tyr136Phe) that enlarge the phenolic binding site result in a 4- to 10-fold increase in activity with sinapaldehyde, which in comparison to the smaller coumaraldehyde and coniferaldehyde substrates is disfavored by wild-type CAD2. This finding demonstrates the potential exploitation of rationally engineered forms of CCR and CAD2 for the targeted modification of monolignol composition in transgenic plants. Thermal denaturation measurements and structural comparisons of various liganded and unliganded forms of CCR and CAD2 highlight substantial conformational flexibility of these SDR enzymes, which plays an important role in the establishment of catalytically productive complexes of the enzymes with their NADPH and phenolic substrates.
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Affiliation(s)
- Haiyun Pan
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
| | - Rui Zhou
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
| | - Gordon V Louie
- Howard Hughes Medical Institute, Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Joëlle K Mühlemann
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
| | - Erin K Bomati
- Howard Hughes Medical Institute, Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, California 92037 Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92037
| | - Marianne E Bowman
- Howard Hughes Medical Institute, Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Natalia Dudareva
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
| | - Richard A Dixon
- Department of Biological Sciences, University of North Texas, Denton, Texas 76203-5017
| | - Joseph P Noel
- Howard Hughes Medical Institute, Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, California 92037 Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92037
| | - Xiaoqiang Wang
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
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Steady state fluorescence studies of wild type recombinant cinnamoyl CoA reductase (Ll-CCRH1) and its active site mutants. J Fluoresc 2013; 24:665-73. [PMID: 24322526 DOI: 10.1007/s10895-013-1343-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 12/02/2013] [Indexed: 10/25/2022]
Abstract
Fluorescence quenching and time resolved fluorescence studies of wild type recombinant cinnamoyl CoA reductase (Ll-CCRH1), a multitryptophan protein from Leucaena leucocephala and 10 different active site mutants were carried out to investigate tryptophan environment. The enzyme showed highest affinity for feruloyl CoA (K(a) = 3.72 × 10(5) M(-1)) over other CoA esters and cinnamaldehydes, as determined by fluorescence spectroscopy. Quenching of the fluorescence by acrylamide for wild type and active site mutants was collisional with almost 100% of the tryptophan fluorescence accessible under native condition and remained same after denaturation of protein with 6 M GdnHCl. In wild type Ll-CCRH1, the extent of quenching achieved with iodide (f(a) = 1.0) was significantly higher than cesium ions (f(a) = 0.33) suggesting more density of positive charge around surface of trp conformers under native conditions. Denaturation of wild type protein with 6 M GdnHCl led to significant increase in the quenching with cesium (f(a) = 0.54), whereas quenching with iodide ion was decreased (f(a) = 0.78), indicating reorientation of charge density around trp from positive to negative and heterogeneity in trp environment. The Stern-Volmer plots for wild type and mutants Ll-CCRH1 under native and denatured conditions, with cesium ion yielded biphasic quenching profiles. The extent of quenching for cesium and iodide ions under native and denatured conditions observed in active site mutants was significantly different from wild type Ll-CCRH1 under the same conditions. Thus, single substitution type mutations of active site residues showed heterogeneity in tryptophan microenvironment and differential degree of conformation of protein under native or denatured conditions.
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Sonawane P, Patel K, Vishwakarma RK, Srivastava S, Singh S, Gaikwad S, Khan BM. Probing the active site of cinnamoyl CoA reductase 1 (Ll-CCRH1) from Leucaena leucocephala. Int J Biol Macromol 2013; 60:33-8. [PMID: 23688416 DOI: 10.1016/j.ijbiomac.2013.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/09/2013] [Accepted: 05/09/2013] [Indexed: 10/26/2022]
Abstract
Lack of three dimensional crystal structure of cinnamoyl CoA reductase (CCR) limits its detailed active site characterization studies. Putative active site residues involved in the substrate/NADPH binding and catalysis for Leucaena leucocephala CCR (Ll-CCRH1; GenBank: DQ986907) were identified by amino acid sequence alignment and homology modeling. Putative active site residues and proximal H215 were subjected for site directed mutagenesis, and mutated enzymes were expressed, purified and assayed to confirm their functional roles. Mutagenesis of S136, Y170 and K174 showed complete loss of activity, indicating their pivotal roles in catalysis. Mutant S212G exhibited the catalytic efficiencies less than 10% of wild type, showing its indirect involvement in substrate binding or catalysis. R51G, D77G, F30V and I31N double mutants showed significant changes in Km values, specifying their roles in substrate binding. Finally, chemical modification and substrate protection studies corroborated the presence Ser, Tyr, Lys, Arg and carboxylate group at the active site of Ll-CCRH1.
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Affiliation(s)
- Prashant Sonawane
- Plant Tissue Culture Division, CSIR-National Chemical Laboratory, Pune-411008, India
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