1
|
Zhang L, Wang X, Zu Y, He Y, Li Z, Li Y. Effects of UV-B Radiation Exposure on Transgenerational Plasticity in Grain Morphology and Proanthocyanidin Content in Yuanyang Red Rice. Int J Mol Sci 2024; 25:4766. [PMID: 38731985 PMCID: PMC11084601 DOI: 10.3390/ijms25094766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/23/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
The effect of UV-B radiation exposure on transgenerational plasticity, the phenomenon whereby the parental environment influences both the parent's and the offspring's phenotype, is poorly understood. To investigate the impact of exposing successive generations of rice plants to UV-B radiation on seed morphology and proanthocyanidin content, the local traditional rice variety 'Baijiaolaojing' was planted on terraces in Yuanyang county and subjected to enhanced UV-B radiation treatments. The radiation intensity that caused the maximum phenotypic plasticity (7.5 kJ·m-2) was selected for further study, and the rice crops were cultivated for four successive generations. The results show that in the same generation, enhanced UV-B radiation resulted in significant decreases in grain length, grain width, spike weight, and thousand-grain weight, as well as significant increases in empty grain percentage and proanthocyanidin content, compared with crops grown under natural light conditions. Proanthocyanidin content increased as the number of generations of rice exposed to radiation increased, but in generation G3, it decreased, along with the empty grain ratio. At the same time, biomass, tiller number, and thousand-grain weight increased, and rice growth returned to control levels. When the offspring's radiation memory and growth environment did not match, rice growth was negatively affected, and seed proanthocyanidin content was increased to maintain seed activity. The correlation analysis results show that phenylalanine ammonialyase (PAL), cinnamate-4-hydroxylase (C4H), dihydroflavonol 4-reductase (DFR), and 4-coumarate:CoA ligase (4CL) enzyme activity positively influenced proanthocyanidin content. Overall, UV-B radiation affected transgenerational plasticity in seed morphology and proanthocyanidin content, showing that rice was able to adapt to this stressor if previous generations had been continuously exposed to treatment.
Collapse
Affiliation(s)
- Lin Zhang
- College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China
| | - Xiupin Wang
- College of Faculty of Animal Science and Technology, Yunnan Agricultural University, Kunming 650201, China
| | - Yanqun Zu
- College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China
| | - Yongmei He
- College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China
| | - Zuran Li
- College of Horticulture and Landscape, Yunnan Agricultural University, Kunming 650201, China
| | - Yuan Li
- College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China
| |
Collapse
|
2
|
Lu N. Revisiting decade-old questions in proanthocyanidin biosynthesis: current understanding and new challenges. FRONTIERS IN PLANT SCIENCE 2024; 15:1373975. [PMID: 38595764 PMCID: PMC11002137 DOI: 10.3389/fpls.2024.1373975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 03/18/2024] [Indexed: 04/11/2024]
Abstract
Proanthocyanidins (PAs), one of the most abundant natural polymers found in plants, are gaining increasing attention because of their beneficial effects for agriculture and human health. The study of PA biosynthesis has been active for decades, and progress has been drastically accelerated since the discovery of key enzymes such as Anthocyanidin Reductase (ANR), Leucoanthocyanidin Reductase (LAR), and key transcription factors such as Transparent Testa 2 (TT2) and Transparent Testa 8 (TT8) in the early 2000s. Scientists raised some compelling questions regarding PA biosynthesis about two decades ago in the hope that addressing these questions would lead to an enhanced understanding of PA biosynthesis in plants. These questions focus on the nature of starter and extension units for PA biosynthesis, the stereochemistry of PA monomers and intermediates, and how and where the polymerization or condensation steps work subcellularly. Here, I revisit these long-standing questions and provide an update on progress made toward answering them. Because of advanced technologies in genomics, bioinformatics and metabolomics, we now have a much-improved understanding of functionalities of key enzymes and identities of key intermediates in the PA biosynthesis and polymerization pathway. Still, several questions, particularly the ones related to intracellular PA transportation and deposition, as well as enzyme subcellular localization, largely remain to be explored. Our increasing understanding of PA biosynthesis in various plant species has led to a new set of compelling open questions, suggesting future research directions to gain a more comprehensive understanding of PA biosynthesis.
Collapse
Affiliation(s)
- Nan Lu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, United States
| |
Collapse
|
3
|
Escaray FJ, Valeri MC, Damiani F, Ruiz OA, Carrasco P, Paolocci F. Multiple bHLH/MYB-based protein complexes regulate proanthocyanidin biosynthesis in the herbage of Lotus spp. PLANTA 2023; 259:10. [PMID: 38041705 PMCID: PMC10693531 DOI: 10.1007/s00425-023-04281-2] [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: 04/26/2023] [Accepted: 11/04/2023] [Indexed: 12/03/2023]
Abstract
MAIN CONCLUSION The complexes involving MYBPA2, TT2b, and TT8 proteins are the critical regulators of ANR and LAR genes to promote the biosynthesis of proanthocyanidins in the leaves of Lotus spp. The environmental impact and health of ruminants fed with forage legumes depend on the herbage's concentration and structure of proanthocyanidins (PAs). Unfortunately, the primary forage legumes (alfalfa and clover) do not contain substantial levels of PAs. No significant progress has been made to induce PAs to agronomically valuable levels in their edible organs by biotechnological approaches thus far. Building this trait requires a profound knowledge of PA regulators and their interplay in species naturally committed to accumulating these metabolites in the target organs. Against this background, we compared the shoot transcriptomes of two inter-fertile Lotus species, namely Lotus tenuis and Lotus corniculatus, polymorphic for this trait, to search for differentially expressed MYB and bHLH genes. We then tested the expression of the above-reported regulators in L. tenuis x L. corniculatus interspecific hybrids, several Lotus spp., and different L. corniculatus organs with contrasting PA levels. We identified a novel MYB activator and MYB-bHLH-based complexes that, when expressed in Nicotiana benthamiana, trans-activated the promoters of L. corniculatus anthocyanidin reductase and leucoanthocyanidin reductase 1 genes. The last are the two critical structural genes for the biosynthesis of PAs in Lotus spp. Competition between MYB activators for the transactivation of these promoters also emerged. Overall, by employing Lotus as a model genus, we refined the transcriptional network underlying PA biosynthesis in the herbage of legumes. These findings are crucial to engineering this trait in pasture legumes.
Collapse
Affiliation(s)
- Francisco José Escaray
- Instituto de Biología Molecular de Plantas (IBMCP) Universitat Politécnica de València - C.S.I.C, Ciudad Politécnica de la Innovación, Edificio 8E, Ingeniero Fausto Elio, s/n, 46022, Valencia, Spain
| | - Maria Cristina Valeri
- Institute of Biosciences and BioResources (IBBR), Consiglio Nazionale Delle Ricerche, Via Madonna Alta, 130, 06128, Perugia, Italy
| | - Francesco Damiani
- Institute of Biosciences and BioResources (IBBR), Consiglio Nazionale Delle Ricerche, Via Madonna Alta, 130, 06128, Perugia, Italy
| | - Oscar Adolfo Ruiz
- Unidad de Biotecnología 1, Instituto Tecnológico de Chascomús (INTECh), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Avenida Intendente Marino KM 8.2, 7130, Chascomús, Buenos Aires, Argentina
| | - Pedro Carrasco
- Biotecmed, Department of Biochemistry and Molecular Biology, University of València, 46100, Burjassot, Valencia, Spain
| | - Francesco Paolocci
- Institute of Biosciences and BioResources (IBBR), Consiglio Nazionale Delle Ricerche, Via Madonna Alta, 130, 06128, Perugia, Italy.
| |
Collapse
|
4
|
Liu Y, Ma D, Constabel CP. CRISPR/Cas9 Disruption of MYB134 and MYB115 in Transgenic Poplar Leads to Differential Reduction of Proanthocyanidin Synthesis in Roots and Leaves. PLANT & CELL PHYSIOLOGY 2023; 64:1189-1203. [PMID: 37522631 DOI: 10.1093/pcp/pcad086] [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: 01/11/2023] [Revised: 07/21/2023] [Accepted: 07/28/2023] [Indexed: 08/01/2023]
Abstract
Proanthocyanidins (PAs) are common specialized metabolites and particularly abundant in trees and woody plants. In poplar (Populus spp.), PA biosynthesis is stress-induced and regulated by two previously studied transcription factors MYB115 and MYB134. To determine the relative contribution of these regulators to PA biosynthesis, we created single- and double-knockout (KO) mutants for both genes in transgenic poplars using CRISPR/Cas9. Knocking out either MYB134 or MYB115 showed reduced PA accumulation and downregulated flavonoid genes in leaves, but MYB134 disruption had the greatest impact and reduced PAs to 30% of controls. In roots, by contrast, only the MYB134/MYB115 double-KOs showed a significant change in PA concentration. The loss of PAs paralleled the lower expression of PA biosynthesis genes and concentrations of flavan-3-ol PA precursors catechin and epicatechin. Interestingly, salicinoids were also affected in double-KOs, with distinct patterns in roots and shoots. We conclude that the regulatory pathways for PA biosynthesis differ in poplar leaves and roots. The residual PA content in the double-KO plants indicates that other transcription factors must also be involved in control of the PA pathway.
Collapse
Affiliation(s)
- Yalin Liu
- Centre for Forest Biology & Department of Biology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P5C3, Canada
| | - Dawei Ma
- Centre for Forest Biology & Department of Biology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P5C3, Canada
| | - C Peter Constabel
- Centre for Forest Biology & Department of Biology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P5C3, Canada
| |
Collapse
|
5
|
Eichenberger M, Schwander T, Hüppi S, Kreuzer J, Mittl PRE, Peccati F, Jiménez-Osés G, Naesby M, Buller RM. The catalytic role of glutathione transferases in heterologous anthocyanin biosynthesis. Nat Catal 2023; 6:927-938. [PMID: 37881531 PMCID: PMC10593608 DOI: 10.1038/s41929-023-01018-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 08/01/2023] [Indexed: 10/27/2023]
Abstract
Anthocyanins are ubiquitous plant pigments used in a variety of technological applications. Yet, after over a century of research, the penultimate biosynthetic step to anthocyanidins attributed to the action of leucoanthocyanidin dioxygenase has never been efficiently reconstituted outside plants, preventing the construction of heterologous cell factories. Through biochemical and structural analysis, here we show that anthocyanin-related glutathione transferases, currently implicated only in anthocyanin transport, catalyse an essential dehydration of the leucoanthocyanidin dioxygenase product, flavan-3,3,4-triol, to generate cyanidin. Building on this knowledge, introduction of anthocyanin-related glutathione transferases into a heterologous biosynthetic pathway in baker's yeast results in >35-fold increased anthocyanin production. In addition to unravelling the long-elusive anthocyanin biosynthesis, our findings pave the way for the colourants' heterologous microbial production and could impact the breeding of industrial and ornamental plants.
Collapse
Affiliation(s)
- Michael Eichenberger
- Competence Center for Biocatalysis, Zurich University of Applied Sciences, Wädenswil, Switzerland
| | - Thomas Schwander
- Competence Center for Biocatalysis, Zurich University of Applied Sciences, Wädenswil, Switzerland
| | - Sean Hüppi
- Competence Center for Biocatalysis, Zurich University of Applied Sciences, Wädenswil, Switzerland
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Jan Kreuzer
- Competence Center for Biocatalysis, Zurich University of Applied Sciences, Wädenswil, Switzerland
| | - Peer R. E. Mittl
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Francesca Peccati
- Center for Cooperative Research in Biosciences, Basque Research and Technology Alliance, Derio, Spain
| | - Gonzalo Jiménez-Osés
- Center for Cooperative Research in Biosciences, Basque Research and Technology Alliance, Derio, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | | | - Rebecca M. Buller
- Competence Center for Biocatalysis, Zurich University of Applied Sciences, Wädenswil, Switzerland
| |
Collapse
|
6
|
Lu N, Jun JH, Li Y, Dixon RA. An unconventional proanthocyanidin pathway in maize. Nat Commun 2023; 14:4349. [PMID: 37468488 DOI: 10.1038/s41467-023-40014-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 07/09/2023] [Indexed: 07/21/2023] Open
Abstract
Proanthocyanidins (PAs), flavonoid polymers involved in plant defense, are also beneficial to human health and ruminant nutrition. To date, there is little evidence for accumulation of PAs in maize (Zea mays), although maize makes anthocyanins and possesses the key enzyme of the PA pathway, anthocyanidin reductase (ANR). Here, we explore whether there is a functional PA biosynthesis pathway in maize using a combination of analytical chemistry and genetic approaches. The endogenous PA biosynthetic machinery in maize preferentially produces the unusual PA precursor (+)-epicatechin, as well as 4β-(S-cysteinyl)-catechin, as potential PA starter and extension units. Uncommon procyanidin dimers with (+)-epicatechin as starter unit are also found. Expression of soybean (Glycine max) anthocyanidin reductase 1 (ANR1) in maize seeds increases the levels of 4β-(S-cysteinyl)-epicatechin and procyanidin dimers mainly using (-)-epicatechin as starter units. Introducing a Sorghum bicolor transcription factor (SbTT2) specifically regulating PA biosynthesis into a maize inbred deficient in anthocyanin biosynthesis activates both anthocyanin and PA biosynthesis pathways, suggesting conservation of the PA regulatory machinery across species. Our data support the divergence of PA biosynthesis across plant species and offer perspectives for future agricultrural applications in maize.
Collapse
Affiliation(s)
- Nan Lu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Ji Hyung Jun
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
- Children's Research Institute and the Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ying Li
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA.
| |
Collapse
|
7
|
Cannavò S, Bertoldi A, Valeri MC, Damiani F, Reale L, Brilli F, Paolocci F. Impact of High Light Intensity and Low Temperature on the Growth and Phenylpropanoid Profile of Azolla filiculoides. Int J Mol Sci 2023; 24:ijms24108554. [PMID: 37239901 DOI: 10.3390/ijms24108554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 05/04/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
Exposure to high light intensity (HL) and cold treatment (CT) induces reddish pigmentation in Azolla filiculoides, an aquatic fern. Nevertheless, how these conditions, alone or in combination, influence Azolla growth and pigment synthesis remains to be fully elucidated. Likewise, the regulatory network underpinning the accumulation of flavonoids in ferns is still unclear. Here, we grew A. filiculoides under HL and/or CT conditions for 20 days and evaluated the biomass doubling time, relative growth rate, photosynthetic and non-photosynthetic pigment contents, and photosynthetic efficiency by chlorophyll fluorescence measurements. Furthermore, from the A. filiculoides genome, we mined the homologs of MYB, bHLH, and WDR genes, which form the MBW flavonoid regulatory complex in higher plants, to investigate their expression by qRT-PCR. We report that A. filiculoides optimizes photosynthesis at lower light intensities, regardless of the temperature. In addition, we show that CT does not severely hamper Azolla growth, although it causes the onset of photoinhibition. Coupling CT with HL stimulates the accumulation of flavonoids, which likely prevents irreversible photoinhibition-induced damage. Although our data do not support the formation of MBW complexes, we identified candidate MYB and bHLH regulators of flavonoids. Overall, the present findings are of fundamental and pragmatic relevance to Azolla's biology.
Collapse
Affiliation(s)
- Sara Cannavò
- Department of Chemistry, Biology, and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Agnese Bertoldi
- Department of Chemistry, Biology, and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Maria Cristina Valeri
- Department of Chemistry, Biology, and Biotechnology, University of Perugia, 06123 Perugia, Italy
- Institute of Bioscience and Bioresources (IBBR), National Research Council of Italy (CNR), 06128 Perugia, Italy
| | - Francesco Damiani
- Institute of Bioscience and Bioresources (IBBR), National Research Council of Italy (CNR), 06128 Perugia, Italy
| | - Lara Reale
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
| | - Federico Brilli
- Institute for Sustainable Plant Protection (IPSP), National Research Council of Italy (CNR), 50017 Sesto Fiorentino, Italy
| | - Francesco Paolocci
- Institute of Bioscience and Bioresources (IBBR), National Research Council of Italy (CNR), 06128 Perugia, Italy
| |
Collapse
|
8
|
Yu K, Song Y, Lin J, Dixon RA. The complexities of proanthocyanidin biosynthesis and its regulation in plants. PLANT COMMUNICATIONS 2023; 4:100498. [PMID: 36435967 PMCID: PMC10030370 DOI: 10.1016/j.xplc.2022.100498] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/07/2022] [Accepted: 11/23/2022] [Indexed: 05/04/2023]
Abstract
Proanthocyanidins (PAs) are natural flavan-3-ol polymers that contribute protection to plants under biotic and abiotic stress, benefits to human health, and bitterness and astringency to food products. They are also potential targets for carbon sequestration for climate mitigation. In recent years, from model species to commercial crops, research has moved closer to elucidating the flux control and channeling, subunit biosynthesis and polymerization, transport mechanisms, and regulatory networks involved in plant PA metabolism. This review extends the conventional understanding with recent findings that provide new insights to address lingering questions and focus strategies for manipulating PA traits in plants.
Collapse
Affiliation(s)
- Keji Yu
- National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Yushuang Song
- National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Jinxing Lin
- National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China.
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China.
| |
Collapse
|