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Huang Y, Chen I, Kao Y, Hsu Y, Tsai C. The gibberellic acid derived from the plastidial MEP pathway is involved in the accumulation of Bamboo mosaic virus. THE NEW PHYTOLOGIST 2022; 235:1543-1557. [PMID: 35524450 PMCID: PMC9543464 DOI: 10.1111/nph.18210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
A gene upregulated in Nicotiana benthamiana after Bamboo mosaic virus (BaMV) infection was revealed as 1-deoxy-d-xylulose-5-phosphate reductoisomerase (NbDXR). DXR is the key enzyme in the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway that catalyzes the conversion of 1-deoxy-d-xylulose 5-phosphate to 2-C-methyl-d-erythritol-4-phosphate. Knockdown and overexpression of NbDXR followed by BaMV inoculation revealed that NbDXR is involved in BaMV accumulation. Treating leaves with fosmidomycin, an inhibitor of DXR function, reduced BaMV accumulation. Subcellular localization confirmed that DXR is a chloroplast-localized protein by confocal microscopy. Furthermore, knockdown of 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate reductase, one of the enzymes in the MEP pathway, also reduced BaMV accumulation. The accumulation of BaMV increased significantly in protoplasts treated with isopentenyl pyrophosphate. Thus, the metabolites of the MEP pathway could be involved in BaMV infection. To identify the critical components involved in BaMV accumulation, we knocked down the crucial enzyme of isoprenoid synthesis, NbGGPPS11 or NbGGPPS2. Only NbGGPPS2 was involved in BaMV infection. The geranylgeranyl pyrophosphate (GGPP) synthesized by NbGGPPS2 is known for gibberellin synthesis. We confirmed this result by supplying gibberellic acid exogenously on leaves, which increased BaMV accumulation. The de novo synthesis of gibberellic acid could assist BaMV accumulation.
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Affiliation(s)
- Ying‐Ping Huang
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
| | - I‐Hsuan Chen
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
| | - Yu‐Shun Kao
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
| | - Yau‐Heiu Hsu
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
- Advaced Plant Biotechnology CenterNational Chung Hsing UniversityTaichung402Taiwan
| | - Ching‐Hsiu Tsai
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
- Advaced Plant Biotechnology CenterNational Chung Hsing UniversityTaichung402Taiwan
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Domokos E, Jakab-Farkas L, Darkó B, Bíró-Janka B, Mara G, Albert C, Balog A. Increase in Artemisia annua Plant Biomass Artemisinin Content and Guaiacol Peroxidase Activity Using the Arbuscular Mycorrhizal Fungus Rhizophagus irregularis. FRONTIERS IN PLANT SCIENCE 2018; 9:478. [PMID: 29706981 PMCID: PMC5908966 DOI: 10.3389/fpls.2018.00478] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 03/28/2018] [Indexed: 05/21/2023]
Abstract
The main objective of this study was to investigate Artemisia annua plant property variations in terms of plant biomass, glandular trichome numbers, artemisinin production and Guaiacol peroxidase (GPOX) activity when plants are in mutualism with AMF. According to the results, A. annua mutualism with AMF significantly increased the most important and pharmaceutically relevant factors of fresh and dry plant biomass. This increase, especially in the biomass of plant herba (leaves), was 30% higher during the vegetation period and remained high (29% higher than for control) when plants were harvested at the end of the vegetation period. Similar differences in dry biomass were also detected. Glandular trichomas numbers increased by 40%, and the artemisinin content by 17% under AMF colonization. No effects due to AMF on chlorophyll variations were detected, while GPOX enzyme concentrations increased significantly under AMF colonization. Altogether the Artemisia plant properties with high pharmaceutically importance (fresh and dry biomass of leaves and artemisinin, number of trichomes and the artemisinin content) were significantly improved by AMF, the application in Artemisia cultivation can be an effective and cheap method. The high GPOX activity under AMF colonization indicate an enhanced oxidative stress alleviation, therefore a higher resistance to water deficiency, mechanisms important under climate conditions with low water supply where Artemisia is usually cultivated.
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Affiliation(s)
- Erzsébet Domokos
- Department of Fundamental Pharmaceutical Sciences, Pharmaceutical Botany, Cell Biology and Microbiology, University of Medicine and Pharmacy of Târgu Mureş, Târgu Mureş, Romania
| | - László Jakab-Farkas
- Department of Electrical Engineering, Sapientia Hungarian University of Transylvania, Cluj-Napoca, Romania
| | - Béla Darkó
- Department of Fundamental Pharmaceutical Sciences, Pharmaceutical Botany, Cell Biology and Microbiology, University of Medicine and Pharmacy of Târgu Mureş, Târgu Mureş, Romania
| | - Béla Bíró-Janka
- Department of Horticulture, Sapientia Hungarian University of Transylvania, Cluj-Napoca, Romania
| | - Gyöngyvér Mara
- Department of Bioengineering, Sapientia Hungarian University of Transylvania, Cluj-Napoca, Romania
| | - Csilla Albert
- Department of Food Science, Sapientia Hungarian University of Transylvania, Cluj-Napoca, Romania
| | - Adalbert Balog
- Department of Horticulture, Sapientia Hungarian University of Transylvania, Cluj-Napoca, Romania
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Perello C, Llamas E, Burlat V, Ortiz-Alcaide M, Phillips MA, Pulido P, Rodriguez-Concepcion M. Differential Subplastidial Localization and Turnover of Enzymes Involved in Isoprenoid Biosynthesis in Chloroplasts. PLoS One 2016; 11:e0150539. [PMID: 26919668 PMCID: PMC4769067 DOI: 10.1371/journal.pone.0150539] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 02/15/2016] [Indexed: 11/23/2022] Open
Abstract
Plastidial isoprenoids are a diverse group of metabolites with roles in photosynthesis, growth regulation, and interaction with the environment. The methylerythritol 4-phosphate (MEP) pathway produces the metabolic precursors of all types of plastidial isoprenoids. Proteomics studies in Arabidopsis thaliana have shown that all the enzymes of the MEP pathway are localized in the plastid stroma. However, immunoblot analysis of chloroplast subfractions showed that the first two enzymes of the pathway, deoxyxylulose 5-phosphate synthase (DXS) and reductoisomerase (DXR), can also be found in non-stromal fractions. Both transient and stable expression of GFP-tagged DXS and DXR proteins confirmed the presence of the fusion proteins in distinct subplastidial compartments. In particular, DXR-GFP was found to accumulate in relatively large vesicles that could eventually be released from chloroplasts, presumably to be degraded by an autophagy-independent process. Together, we propose that protein-specific mechanisms control the localization and turnover of the first two enzymes of the MEP pathway in Arabidopsis chloroplasts.
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Affiliation(s)
- Catalina Perello
- Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
| | - Ernesto Llamas
- Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
| | - Vincent Burlat
- Université de Toulouse, CNRS, UMR 5546, BP 42617 Auzeville, 31326 Castanet-Tolosan, France
| | - Miriam Ortiz-Alcaide
- Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
| | - Michael A. Phillips
- Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
| | - Pablo Pulido
- Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
| | - Manuel Rodriguez-Concepcion
- Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
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Zhang H, Niu D, Wang J, Zhang S, Yang Y, Jia H, Cui H. Engineering a Platform for Photosynthetic Pigment, Hormone and Cembrane-Related Diterpenoid Production in Nicotiana tabacum. PLANT & CELL PHYSIOLOGY 2015; 56:2125-38. [PMID: 26363359 DOI: 10.1093/pcp/pcv131] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 09/08/2015] [Indexed: 12/16/2023]
Abstract
Plants synthesize a large number of isoprenoids that are of nutritional, medicinal and industrial importance. 1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) catalyzes the first committed step for plastidial isoprenoid biosynthesis. Here, we identified two DXR isogenes, designated NtDXR1 and NtDXR2, from tetraploid common tobacco (Nicotiana tabacum L.). Southern blotting and genotyping analysis revealed that two NtDXR genes existed in the tetraploid tobacco genome; NtDXR1 and NtDXR2 were separately derived from N. tomentosiformis and N. sylvestris. Both NtDXRs were localized in chloroplasts. Expression patterns indicated that NtDXR1 and NtDXR2 had similar expression profiles. NtDXR genes were highly expressed in leaves with or without trichomes; expression was relatively reduced in flowers and stems, weak in leaf trichomes and marginal in roots and seeds. Overexpressing NtDXR1 under control of the 35S promoter resulted in longer primary roots and enhancement of various photosynthetic pigments and hormones in leaves. In contrast, there were no significant changes in cembrane-related diterpenoids synthesized in glandular trichomes. To elucidate further the function of DXR in the biosynthesis of diterpenoids, overexpression vectors for NtDXR1 under the control of a trichome-specific CYP promoter were transferred to tobacco plants. CYP:NtDXR1 tobacco exhibited larger glandular cells and increased cembrane-related diterpenoids in leaf glandular trichomes. Moreover, transcripts of eight MEP (2-C-methyl-d-erythritol 4-phosphate) pathway genes were significantly up-regulated in NtDXR1-overexpressing tobacco plants, indicating that overexpression of NtDXR could boost the expression of downstream genes in the MEP pathway. Our results suggested that overexpression of NtDXR1 could increase the levels of photosynthetic pigments, leaf surface exudates and hormones though the MEP pathway.
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Affiliation(s)
- Hongying Zhang
- Key Laboratory for Cultivation of Tobacco Industry, College of Tobacco Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Dexin Niu
- Key Laboratory for Cultivation of Tobacco Industry, College of Tobacco Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Jing Wang
- Key Laboratory for Cultivation of Tobacco Industry, College of Tobacco Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Songtao Zhang
- Key Laboratory for Cultivation of Tobacco Industry, College of Tobacco Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yongxia Yang
- Key Laboratory for Cultivation of Tobacco Industry, College of Tobacco Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Hongfang Jia
- Key Laboratory for Cultivation of Tobacco Industry, College of Tobacco Science, Henan Agricultural University, Zhengzhou, 450002, China
| | - Hong Cui
- Key Laboratory for Cultivation of Tobacco Industry, College of Tobacco Science, Henan Agricultural University, Zhengzhou, 450002, China
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Rey MD, Calderón MC, Rodrigo MJ, Zacarías L, Alós E, Prieto P. Novel Bread Wheat Lines Enriched in Carotenoids Carrying Hordeum chilense Chromosome Arms in the ph1b Background. PLoS One 2015; 10:e0134598. [PMID: 26241856 PMCID: PMC4524710 DOI: 10.1371/journal.pone.0134598] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/13/2015] [Indexed: 01/17/2023] Open
Abstract
The use of crop wild relative species to improve major crops performance is well established. Hordeum chilense has a high potential as a genetic donor to increase the carotenoid content of wheat. Crosses between the 7HchH. chilense substitution lines in wheat and the wheat pairing homoeologous1b (ph1b) mutant allowed the development of wheat-H. chilense translocation lines for both 7Hchα and 7Hchβ chromosome arms in the wheat background. These translocation lines were characterized by in situ hybridization and using molecular markers. In addition, reverse phase chromatography (HPLC) analysis was carried out to evaluate the carotenoid content and both 7Hchα∙7AL and 7AS∙7Hchβ disomic translocation lines. The carotenoid content in 7Hchα∙7AL and 7AS∙7Hchβ disomic translocation lines was higher than the wheat-7Hch addition line and double amount of carotenoids than the wheat itself. A proteomic analysis confirmed that the presence of chromosome 7Hch introgressions in wheat scarcely altered the proteomic profile of the wheat flour. The Psy1 (Phytoene Synthase1) gene, which is the first committed step in the carotenoid biosynthetic pathway, was also cytogenetically mapped on the 7Hchα chromosome arm. These new wheat-H. chilense translocation lines can be used as a powerful tool in wheat breeding programs to enrich the diet in bioactive compounds.
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Affiliation(s)
- María-Dolores Rey
- Departamento de Mejora Genética Vegetal, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas, Apartado, Córdoba, Spain
| | - María-Carmen Calderón
- Departamento de Mejora Genética Vegetal, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas, Apartado, Córdoba, Spain
| | - María Jesús Rodrigo
- Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | - Lorenzo Zacarías
- Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | - Enriqueta Alós
- Departamento de Mejora Genética Vegetal, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas, Apartado, Córdoba, Spain
| | - Pilar Prieto
- Departamento de Mejora Genética Vegetal, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas, Apartado, Córdoba, Spain
- * E-mail:
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Rodríguez-Concepción M, Boronat A. Breaking new ground in the regulation of the early steps of plant isoprenoid biosynthesis. CURRENT OPINION IN PLANT BIOLOGY 2015; 25:17-22. [PMID: 25909859 DOI: 10.1016/j.pbi.2015.04.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 04/01/2015] [Accepted: 04/03/2015] [Indexed: 05/18/2023]
Abstract
The common metabolic precursors used for the production of all isoprenoid compounds are synthesized by two unrelated pathways in plants. The methylerythritol 4-phosphate (MEP) pathway produces these precursors in the plastid, whereas the biosynthesis of non-plastidial isoprenoids relies on the operation of the mevalonic acid (MVA) pathway. Despite the physical separation of the two pathways, some interaction exists at molecular and metabolic levels. Recent results have provided strong evidence that a high degree of control over each individual pathway takes place at the post-translational level. In particular, new mechanisms regulating the levels and activity of rate-determining enzymes have been unveiled. Current challenges include the study of the subcellular operation of the MEP and MVA pathways and their coordination with upstream and downstream pathways that supply their substrates and consume their products.
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Affiliation(s)
- Manuel Rodríguez-Concepción
- Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, E-08193, Barcelona, Spain.
| | - Albert Boronat
- Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, E-08193, Barcelona, Spain; Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
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Hsieh WY, Sung TY, Wang HT, Hsieh MH. Functional evidence for the critical amino-terminal conserved domain and key amino acids of Arabidopsis 4-HYDROXY-3-METHYLBUT-2-ENYL DIPHOSPHATE REDUCTASE. PLANT PHYSIOLOGY 2014; 166:57-69. [PMID: 25037211 PMCID: PMC4149731 DOI: 10.1104/pp.114.243642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The plant 4-HYDROXY-3-METHYLBUT-2-ENYL DIPHOSPHATE REDUCTASE (HDR) catalyzes the last step of the methylerythritol phosphate pathway to synthesize isopentenyl diphosphate and its allyl isomer dimethylallyl diphosphate, which are common precursors for the synthesis of plastid isoprenoids. The Arabidopsis (Arabidopsis thaliana) genomic HDR transgene-induced gene-silencing lines are albino, variegated, or pale green, confirming that HDR is essential for plants. We used Escherichia coli isoprenoid synthesis H (Protein Data Bank code 3F7T) as a template for homology modeling to identify key amino acids of Arabidopsis HDR. The predicted model reveals that cysteine (Cys)-122, Cys-213, and Cys-350 are involved in iron-sulfur cluster formation and that histidine (His)-152, His-241, glutamate (Glu)-242, Glu-243, threonine (Thr)-244, Thr-312, serine-379, and asparagine-381 are related to substrate binding or catalysis. Glu-242 and Thr-244 are conserved only in cyanobacteria, green algae, and land plants, whereas the other key amino acids are absolutely conserved from bacteria to plants. We used site-directed mutagenesis and complementation assay to confirm that these amino acids, except His-152 and His-241, were critical for Arabidopsis HDR function. Furthermore, the Arabidopsis HDR contains an extra amino-terminal domain following the transit peptide that is highly conserved from cyanobacteria, and green algae to land plants but not existing in the other bacteria. We demonstrated that the amino-terminal conserved domain was essential for Arabidopsis and cyanobacterial HDR function. Further analysis of conserved amino acids in the amino-terminal conserved domain revealed that the tyrosine-72 residue was critical for Arabidopsis HDR. These results suggest that the structure and reaction mechanism of HDR evolution have become specific for oxygen-evolving photosynthesis organisms and that HDR probably evolved independently in cyanobacteria versus other prokaryotes.
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Affiliation(s)
- Wei-Yu Hsieh
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Tzu-Ying Sung
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Hsin-Tzu Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Ming-Hsiun Hsieh
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
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Lajkiewicz NJ, Roche SP, Gerard B, Porco JA. Enantioselective photocycloaddition of 3-hydroxyflavones: total syntheses and absolute configuration assignments of (+)-ponapensin and (+)-elliptifoline. J Am Chem Soc 2012; 134:13108-13. [PMID: 22804454 PMCID: PMC3529213 DOI: 10.1021/ja305342f] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have previously reported development of biomimetic, asymmetric [3 + 2] photocycloadditions between 3-hydroxyflavones and cinnamate dipolarophiles to access (-)-rocaglamide and related natural products. Herein, we describe enantioselective syntheses of aglain cycloadducts leading to the first total syntheses and absolute configuration assignments of the aglain natural products (+)-ponapensin and (+)-elliptifoline.
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Affiliation(s)
- Neil J. Lajkiewicz
- Department of Chemistry, Center for Chemical Methodology and Library Development (CMLD-BU), Boston University, 590 Commonwealth Avenue, Boston, MA 02215, United States
| | | | | | - John A. Porco
- Department of Chemistry, Center for Chemical Methodology and Library Development (CMLD-BU), Boston University, 590 Commonwealth Avenue, Boston, MA 02215, United States
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Arsenault PR, Vail D, Wobbe KK, Erickson K, Weathers PJ. Reproductive development modulates gene expression and metabolite levels with possible feedback inhibition of artemisinin in Artemisia annua. PLANT PHYSIOLOGY 2010; 154:958-68. [PMID: 20724645 PMCID: PMC2949044 DOI: 10.1104/pp.110.162552] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 08/16/2010] [Indexed: 05/19/2023]
Abstract
The relationship between the transition to budding and flowering in Artemisia annua and the production of the antimalarial sesquiterpene, artemisinin (AN), the dynamics of artemisinic metabolite changes, AN-related transcriptional changes, and plant and trichome developmental changes were measured. Maximum production of AN occurs during full flower stage within floral tissues, but that changes in the leafy bracts and nonbolt leaves as the plant shifts from budding to full flower. Expression levels of early pathway genes known to be involved in isopentenyl diphosphate and farnesyl diphosphate biosynthesis leading to AN were not immediately positively correlated with either AN or its precursors. However, we found that the later AN pathway genes, amorpha-4,11-diene synthase (ADS) and the cytochrome P450, CYP71AV1 (CYP), were more highly correlated with AN's immediate precursor, dihydroartemisinic acid, within all leaf tissues tested. In addition, leaf trichome formation throughout the developmental phases of the plant also appears to be more complex than originally thought. Trichome changes correlated closely with the levels of AN but not its precursors. Differences were observed in trichome densities that are dependent both on developmental stage (vegetative, budding, and flowering) and on position (upper and lower leaf tissue). AN levels declined significantly as plants matured, as did ADS and CYP transcripts. Spraying leaves with AN or artemisinic acid inhibited CYP transcription; artemisinic acid also inhibited ADS transcription. These data allow us to present a novel model for the differential control of AN biosynthesis as it relates to developmental stage and trichome maturation and collapse.
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