1
|
Grover S, Mou DF, Shrestha K, Puri H, Pingault L, Sattler SE, Louis J. Impaired Brown midrib12 function orchestrates sorghum resistance to aphids via an auxin conjugate indole-3-acetic acid-aspartic acid. THE NEW PHYTOLOGIST 2024. [PMID: 39233513 DOI: 10.1111/nph.20091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 08/08/2024] [Indexed: 09/06/2024]
Abstract
Lignin, a complex heterogenous polymer present in virtually all plant cell walls, plays a critical role in protecting plants from various stresses. However, little is known about how lignin modifications in sorghum will impact plant defense against sugarcane aphids (SCA), a key pest of sorghum. We utilized the sorghum brown midrib (bmr) mutants, which are impaired in monolignol synthesis, to understand sorghum defense mechanisms against SCA. We found that loss of Bmr12 function and overexpression (OE) of Bmr12 provided enhanced resistance and susceptibility to SCA, respectively, as compared with wild-type (WT; RTx430) plants. Monitoring of the aphid feeding behavior indicated that SCA spent more time in reaching the first sieve element phase on bmr12 plants compared with RTx430 and Bmr12-OE plants. A combination of transcriptomic and metabolomic analyses revealed that bmr12 plants displayed altered auxin metabolism upon SCA infestation and specifically, elevated levels of auxin conjugate indole-3-acetic acid-aspartic acid (IAA-Asp) were observed in bmr12 plants compared with RTx430 and Bmr12-OE plants. Furthermore, exogenous application of IAA-Asp restored resistance in Bmr12-OE plants, and artificial diet aphid feeding trial bioassays revealed that IAA-Asp is associated with enhanced resistance to SCA. Our findings highlight the molecular underpinnings that contribute to sorghum bmr12-mediated resistance to SCA.
Collapse
Affiliation(s)
- Sajjan Grover
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - De-Fen Mou
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Kumar Shrestha
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Heena Puri
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Lise Pingault
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Scott E Sattler
- Wheat, Sorghum, and Forage Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Lincoln, NE, 68583, USA
| | - Joe Louis
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| |
Collapse
|
2
|
Funnell-Harris DL, Sattler SE, O'Neill PM, Gries T, Ge Z, Nersesian N. Effects of Altering Three Steps of Monolignol Biosynthesis on Sorghum Responses to Stalk Pathogens and Water Deficit. PLANT DISEASE 2023; 107:3984-3995. [PMID: 37430480 DOI: 10.1094/pdis-08-22-1959-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
The drought-resilient crop sorghum (Sorghum bicolor [L.] Moench) is grown worldwide for multiple uses, including forage or potential lignocellulosic bioenergy feedstock. A major impediment to biomass yield and quality are the pathogens Fusarium thapsinum and Macrophomina phaseolina, which cause Fusarium stalk rot and charcoal rot, respectively. These fungi are more virulent with abiotic stresses such as drought. Monolignol biosynthesis plays a critical role in plant defense. The genes Brown midrib (Bmr)6, Bmr12, and Bmr2 encode the monolignol biosynthesis enzymes cinnamyl alcohol dehydrogenase, caffeic acid O-methyltransferase, and 4-coumarate:CoA ligase, respectively. Plant stalks from lines overexpressing these genes and containing bmr mutations were screened for pathogen responses with controlled adequate or deficit watering. Additionally, near-isogenic bmr12 and wild-type lines in five backgrounds were screened for response to F. thapsinum with adequate and deficit watering. All mutant and overexpression lines were no more susceptible than corresponding wild-type under both watering conditions. The bmr2 and bmr12 lines, near-isogenic to wild-type, had significantly shorter mean lesion lengths (were more resistant) than RTx430 wild-type when inoculated with F. thapsinum under water deficit. Additionally, bmr2 plants grown under water deficit had significantly smaller mean lesions when inoculated with M. phaseolina than under adequate-water conditions. When well-watered, bmr12 in cultivar Wheatland and one of two Bmr2 overexpression lines in RTx430 had shorter mean lesion lengths than corresponding wild-type lines. This research demonstrates that modifying monolignol biosynthesis for increased usability may not impair plant defenses but can even enhance resistance to stalk pathogens under drought conditions.
Collapse
Affiliation(s)
- Deanna L Funnell-Harris
- Wheat, Sorghum, and Forage Research Unit, United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Lincoln, NE 68583
- Department of Plant Pathology, University of Nebraska, Lincoln (UNL), Lincoln, NE 68583
| | - Scott E Sattler
- Wheat, Sorghum, and Forage Research Unit, United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Lincoln, NE 68583
- Department of Agronomy and Horticulture, UNL, Lincoln, NE 68583
| | - Patrick M O'Neill
- Wheat, Sorghum, and Forage Research Unit, United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Lincoln, NE 68583
- Department of Plant Pathology, University of Nebraska, Lincoln (UNL), Lincoln, NE 68583
| | - Tammy Gries
- Wheat, Sorghum, and Forage Research Unit, United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Lincoln, NE 68583
- Department of Agronomy and Horticulture, UNL, Lincoln, NE 68583
| | - Zhengxiang Ge
- Department of Agronomy and Horticulture, UNL, Lincoln, NE 68583
| | | |
Collapse
|
3
|
Saluja M, Zhu F, Yu H, Walia H, Sattler SE. Loss of COMT activity reduces lateral root formation and alters the response to water limitation in sorghum brown midrib (bmr) 12 mutant. THE NEW PHYTOLOGIST 2021; 229:2780-2794. [PMID: 33124063 DOI: 10.1111/nph.17051] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 10/22/2020] [Indexed: 06/11/2023]
Abstract
Lignin is a key target for modifying lignocellulosic biomass for efficient biofuel production. Brown midrib 12 (bmr12) encodes the sorghum caffeic acid O-methyltransferase (COMT) and is one of the key enzymes in monolignol biosynthesis. Loss of function mutations in COMT reduces syringyl (S) lignin subunits and improves biofuel conversion rate. Although lignin plays an important role in maintaining cell wall integrity of xylem vessels, physiological and molecular consequences due to loss of COMT on root growth and adaptation to water deficit remain unexplored. We addressed this gap by evaluating the root morphology, anatomy and transcriptome of bmr12 mutant. The mutant had reduced lateral root density (LRD) and altered root anatomy and response to water limitation. The wild-type exhibits similar phenotypes under water stress, suggesting that bmr12 may be in a water deficit responsive state even in well-watered conditions. bmr12 had increased transcript abundance of genes involved in (a)biotic stress response, gibberellic acid (GA) biosynthesis and signaling. We show that bmr12 is more sensitive to exogenous GA application and present evidence for the role of GA in regulating reduced LRD in bmr12. These findings elucidate the phenotypic and molecular consequences of COMT deficiency under optimal and water stress environments in grasses.
Collapse
Affiliation(s)
- Manny Saluja
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Feiyu Zhu
- Computer Science and Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Hongfeng Yu
- Computer Science and Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Harkamal Walia
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Scott E Sattler
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
- Wheat, Sorghum and Forage Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
| |
Collapse
|
4
|
Chen J, Song M, Wu X, Zheng J, He L, McClements DJ, Decker E, Xiao H. Direct Fluorescent Detection of a Polymethoxyflavone in Cell Culture and Mouse Tissue. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:10620-10627. [PMID: 26618604 DOI: 10.1021/acs.jafc.5b04484] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Convenient detection methods for bioactive food compounds and their metabolites in biological samples are needed to better understand their mechanism of actions. Herein, we developed a novel approach to directly monitor and visualize the distribution of 5,3',4'-tridemethylnobiletin (TDN), a unique polymethoxyflavone metabolite derived from citrus polymethoxyflavone, in biological samples such as cultured cells and mouse colonic tissues. Our results showed that a fluorescent conjugate could be formed between TDN and 2-aminoethyl diphenyl borate (DPBA) under simple reaction conditions, which was confirmed by both Raman spectroscopy and mass spectroscopy. We further demonstrated the application of DPBA-based conjugation reaction in the characterization of TDN in different biological samples including floating cells, adherent cells, and animal tissues. This is the first report demonstrating direct fluorescent detection of polymethoxyflavone in biological samples.
Collapse
Affiliation(s)
- Jingjing Chen
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Mingyue Song
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Xian Wu
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Jinkai Zheng
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences , Beijing 100193, People's Republic of China
| | - Lili He
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - David Julian McClements
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Eric Decker
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Hang Xiao
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
- College of Bioscience and Biotechnology, Hunan Agricultural University , Changsha, Hunan 410128, People's Republic of China
| |
Collapse
|
5
|
Dahlin JL, Nissink JWM, Strasser JM, Francis S, Higgins L, Zhou H, Zhang Z, Walters MA. PAINS in the assay: chemical mechanisms of assay interference and promiscuous enzymatic inhibition observed during a sulfhydryl-scavenging HTS. J Med Chem 2015; 58:2091-113. [PMID: 25634295 PMCID: PMC4360378 DOI: 10.1021/jm5019093] [Citation(s) in RCA: 250] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Significant resources in early drug discovery are spent unknowingly pursuing artifacts and promiscuous bioactive compounds, while understanding the chemical basis for these adverse behaviors often goes unexplored in pursuit of lead compounds. Nearly all the hits from our recent sulfhydryl-scavenging high-throughput screen (HTS) targeting the histone acetyltransferase Rtt109 were such compounds. Herein, we characterize the chemical basis for assay interference and promiscuous enzymatic inhibition for several prominent chemotypes identified by this HTS, including some pan-assay interference compounds (PAINS). Protein mass spectrometry and ALARM NMR confirmed these compounds react covalently with cysteines on multiple proteins. Unfortunately, compounds containing these chemotypes have been published as screening actives in reputable journals and even touted as chemical probes or preclinical candidates. Our detailed characterization and identification of such thiol-reactive chemotypes should accelerate triage of nuisance compounds, guide screening library design, and prevent follow-up on undesirable chemical matter.
Collapse
Affiliation(s)
- Jayme L Dahlin
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine , Rochester, Minnesota 55905, United States
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Schulz D, Rentmeister A. An enzyme-coupled high-throughput assay for screening RNA methyltransferase activity inE. Colicell lysate. RNA Biol 2014; 9:577-86. [DOI: 10.4161/rna.19818] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
|
7
|
Contrasting metabolism in perenniating structures of upland and lowland switchgrass plants late in the growing season. PLoS One 2014; 9:e105138. [PMID: 25133804 PMCID: PMC4136849 DOI: 10.1371/journal.pone.0105138] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 07/17/2014] [Indexed: 12/24/2022] Open
Abstract
Background Switchgrass (Panicum virgatum L.) is being developed as a bioenergy crop for many temperate regions of the world. One way to increase biomass yields is to move southern adapted lowland cultivars to more northern latitudes. However, many southerly adapted switchgrass germplasm can suffer significant winter kill in northerly climes. Materials and Methods Here, we have applied next-generation sequencing in combination with biochemical analyses to query the metabolism of crowns and rhizomes obtained from two contrasting switchgrass cultivars. Crowns and rhizomes from field-grown lowland (cv Kanlow) and upland (cv Summer) switchgrass cultivars were collected from three randomly selected post-flowering plants. Summer plants were senescing, whereas Kanlow plants were not at this harvest date. Results Principal component analysis (PCA) differentiated between both the Summer and Kanlow transcriptomes and metabolomes. Significant differences in transcript abundances were detected for 8,050 genes, including transcription factors such as WRKYs and those associated with phenylpropanoid biosynthesis. Gene-set enrichment analyses showed that a number of pathways were differentially up-regulated in the two populations. For both populations, protein levels and enzyme activities agreed well with transcript abundances for genes involved in the phenylpropanoid pathway that were up-regulated in Kanlow crowns and rhizomes. The combination of these datasets suggests that dormancy-related mechanisms had been triggered in the crowns and rhizomes of the Summer plants, whereas the crowns and rhizomes of Kanlow plants had yet to enter dormancy. Conclusions Delayed establishment of dormancy at more northerly latitudes could be one factor that reduces winter-survival in the high-yielding Kanlow plants. Understanding the cellular signatures that accompany the transition to dormancy can be used in the future to select plants with improved winter hardiness.
Collapse
|
8
|
Lozada-Ramírez JD, Sánchez-Ferrer A, García-Carmona F. Recombinant S-adenosylhomocysteine hydrolase from Thermotoga maritima: cloning, overexpression, characterization, and thermal purification studies. Appl Biochem Biotechnol 2013; 170:639-53. [PMID: 23588970 DOI: 10.1007/s12010-013-0218-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Accepted: 04/01/2013] [Indexed: 01/24/2023]
Abstract
S-Adenosylhomocysteine hydrolase (SAHase) encoded by sahase gene is a determinant when catalyzing the reversible conversion of adenosine and homocysteine to S-adenosylhomocysteine in most living organisms. The sahase gene was isolated from the genome of the highly thermostable anaerobic bacteria Thermotoga maritima, and then it was cloned, characterized, overexpressed using Escherichia coli, and partially purified by thermal precipitation. The thermal purification of the recombinant SAHase resulted in changes in the circular dichroism spectra. As a result of this analysis, it was possible to determine the structural changes in the composition of the α-helix and β-sheet content of the recombinant enzyme after purification. Moreover, a predicted secondary structure and 3D structural model was rendered by comparative molecular modeling to further understand the molecular function of this protein including its attractive biotechnological use.
Collapse
Affiliation(s)
- J D Lozada-Ramírez
- Department of Chemical and Biological Sciences, School of Sciences, Universidad de las Américas Puebla, Santa Catarina Mártir Cholula 72820, Puebla, México.
| | | | | |
Collapse
|
9
|
Wu X, Wu J, Luo Y, Bragg J, Anderson O, Vogel J, Gu YQ. Phylogenetic, Molecular, and Biochemical Characterization of Caffeic Acid o-Methyltransferase Gene Family in Brachypodium distachyon. INTERNATIONAL JOURNAL OF PLANT GENOMICS 2013; 2013:423189. [PMID: 23431288 PMCID: PMC3562662 DOI: 10.1155/2013/423189] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/03/2012] [Accepted: 12/07/2012] [Indexed: 05/02/2023]
Abstract
Caffeic acid o-methyltransferase (COMT) is one of the important enzymes controlling lignin monomer production in plant cell wall synthesis. Analysis of the genome sequence of the new grass model Brachypodium distachyon identified four COMT gene homologs, designated as BdCOMT1, BdCOMT2, BdCOMT3, and BdCOMT4. Phylogenetic analysis suggested that they belong to the COMT gene family, whereas syntenic analysis through comparisons with rice and sorghum revealed that BdCOMT4 on Chromosome 3 is the orthologous copy of the COMT genes well characterized in other grass species. The other three COMT genes are unique to Brachypodium since orthologous copies are not found in the collinear regions of rice and sorghum genomes. Expression studies indicated that all four Brachypodium COMT genes are transcribed but with distinct patterns of tissue specificity. Full-length cDNAs were cloned in frame into the pQE-T7 expression vector for the purification of recombinant Brachypodium COMT proteins. Biochemical characterization of enzyme activity and substrate specificity showed that BdCOMT4 has significant effect on a broad range of substrates with the highest preference for caffeic acid. The other three COMTs had low or no effect on these substrates, suggesting that a diversified evolution occurred on these duplicate genes that not only impacted their pattern of expression, but also altered their biochemical properties.
Collapse
Affiliation(s)
- Xianting Wu
- Western Regional Research Center, USDA-ARS, 800 Buchanan Street, Albany, CA 94710, USA
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
| | - Jiajie Wu
- State Key Laboratory of Crop Biology, Shandong Agricultural University, 61 Daizong Avenue, Tai'an, Shandong 271018, China
| | - Yangfan Luo
- Western Regional Research Center, USDA-ARS, 800 Buchanan Street, Albany, CA 94710, USA
| | - Jennifer Bragg
- Western Regional Research Center, USDA-ARS, 800 Buchanan Street, Albany, CA 94710, USA
| | - Olin Anderson
- Western Regional Research Center, USDA-ARS, 800 Buchanan Street, Albany, CA 94710, USA
| | - John Vogel
- Western Regional Research Center, USDA-ARS, 800 Buchanan Street, Albany, CA 94710, USA
| | - Yong Q. Gu
- Western Regional Research Center, USDA-ARS, 800 Buchanan Street, Albany, CA 94710, USA
- *Yong Q. Gu:
| |
Collapse
|
10
|
Allali-Hassani A, Wasney GA, Siarheyeva A, Hajian T, Arrowsmith CH, Vedadi M. Fluorescence-based methods for screening writers and readers of histone methyl marks. ACTA ACUST UNITED AC 2011; 17:71-84. [PMID: 21972038 DOI: 10.1177/1087057111422256] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The histone methyltransferase (HMT) family of proteins consists of enzymes that methylate lysine or arginine residues on histone tails as well as other proteins. Such modifications affect chromatin structure and play a significant regulatory role in gene expression. Many HMTs have been implicated in tumorigenesis and progression of multiple malignancies and play essential roles in embryonic development and stem cell renewal. Overexpression of some HMTs has been observed and is correlated positively with various types of cancer. Here the authors report development of a continuous fluorescence-based methyltransferase assay in a 384-well format and its application in determining kinetic parameters for EHMT1, G9a, PRMT3, SETD7, and SUV39H2 as well as for screening against libraries of small molecules to identify enzyme inhibitors. They also report the development of a peptide displacement assay using fluorescence polarization in a 384-well format to assay and screen protein peptide interactions such as those of WDR5 and EED, components of MLL and EZH2 methyltransferase complexes. Using these high-throughput screening methods, the authors have identified potent inhibitors and ligands for some of these proteins.
Collapse
|