FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W3048247841> ?p ?o ?g. }

• W3048247841 endingPage "14" @default.
• W3048247841 startingPage "11" @default.
• W3048247841 abstract "This article is a Commentary on Lui et al. (2020), 228: 269–284. ‘Medicago legumes have evolved their own distinct set of enzymes for tricin biosynthesis.’ Lignin research has sporadically produced startling new insights, and at a rapid pace since the genetics revolution (Ralph et al., 2019; Vanholme et al., 2019). The ability to perturb the expression of single genes in the pathway gave researchers significant insight into the flexibility of lignification, the purely combinatorial chemical process of polymerizing monomers into the polymer, and necessitated a broad definitional change to include monomers beyond the canonical monolignols. Studies on various natural plants and different tissues have further continued to produce their own striking revelations. Perhaps none has been as remarkable as the discovery that tricin is a lignin monomer in a huge plant lineage, the commelinid monocots. Revealed in a paper from an ostensibly unassuming study characterizing wheat straw lignin, tricin (Fig. 1) was validated as a lignin component, and its integration into the polymer was indicated and then established beyond reasonable doubt (del Río et al., 2012). Although it could have been predicted from lignification's clear metabolic malleability (Ralph et al., 2019), tricin was the first phenolic component biosynthesized from outside the phenylpropanoid pathway to be established as an authentic lignin monomer, copolymerizing alongside the canonical monolignols, albeit joining a slew of other phenolics originating from the lignin pathway (Ralph et al., 2019; Vanholme et al., 2019). Tricin's role as a monomer has since been augmented by a set of hydroxystilbenes, also from a combination of the shikimate-derived phenylpropanoid and acetate/malonate-derived polyketide pathways (Fig. 1), and beyond (del Río et al., 2017, 2020). These discoveries exploited the power of, and advances in, metabolite profiling and nuclear magnetic resonance (NMR) methods to elucidate the ‘new’ structures in the lignins, and their derivation, as well as to establish their true incorporation into the polymer (Lan et al., 2015, 2016a). In addition, the reevaluation of novel products in traditional and new analyses facilitated the discoveries and helped prove a monomer's incorporation into lignin. New products, many of which have become valuable markers, from analytical thioacidolysis first established the incorporation into lignins of hydroxycinnamaldehydes (from incomplete reduction to the monolignols), caffeyl alcohol and 5-hydroxyconiferyl alcohol (from incomplete methylation), and hydroxycinnamates, as reviewed in Ralph et al. (2004). Development and deployment of new methods may be key to revealing new pathways. For example, it was not until after attempting to introduce novel monolignol ferulate conjugates (Fig. 1) into lignins, and the development of a method to establish success, was it revealed that such components were ‘always’ being incorporated into lignification in a range of native plant lines (Wilkerson et al., 2014; Karlen et al., 2016). Until that point, their role had gone unnoticed simply because no definitive assay existed for determining not just the existence of such conjugates but, importantly, that they were being integrally incorporated into the polymer during lignification. Tricin's discovery in monocot lignins also added to the long-appreciated realization that grasses, and commelinid monocots in general, are special in the plant kingdom. For evolutionary reasons about which we can only superficially speculate, grasses have at least four notable plant cell wall traits, none of which is unique but their combination is striking. (1) Commelinids have ferulates (and p-coumarates) specifically attached to arabinoxylans (acylating the C5-OH of arabinosyl units on (glucurono)arabinoxylans), that function to provide powerful mechanisms to strengthen the cell wall by cross-linking both polysaccharides (with each other) and polysaccharides with lignin (Ralph, 2010). (2) Grasses have hydroxycinnamates acylating the lignins, now established to arise via the pre-acylation of monolignols to produce conjugates that are then sent to the wall for otherwise normal lignification (Fig. 1, bottom left), as reviewed (Ralph, 2010). p-Coumarates had long been known, and had been established to arise from monolignol p-coumarate conjugates, but monolignol ferulates as authentic lignin precursors have been only more recently discovered (Karlen et al., 2016). (3) Not to leave out the polysaccharides, grasses contain mixed-linkage (1→3,1→4) glucan polysaccharides (Henry & Harris, 1997). (4) As most recently revealed, grass lignins also contain tricin that resulted from its integration into the radical coupling process of lignification. Tricin levels can be as high as c. 3.3 wt% of the lignin (Lan et al., 2016b), striking levels given that tricin is capable only of starting a lignin chain and mechanistically cannot inculcate itself into an already growing polymer chain. With some 100 million dry tons (MT) of corn stover produced annually in the United States and an anticipated 250 MT augmented by miscanthus, switchgrass, and wheat straw under a given pricing scenario (according to the Department of Energy’s 2016 ‘Billion-Ton Report’, https://www.energy.gov/eere/bioenergy/2016-billion-ton-report), and at a nominal 15% lignin, this translates to some 38 MT of lignin that, at just 1.5 wt% tricin, contains over half a MT of tricin. Releasing that component from its polymer efficiently and economically is a serious challenge, but a currently low-availability yet potentially valuable pharmaceutical, nutraceutical, and agricultural-chemical product is suddenly recognized as being accessible in huge quantities. It is with this background that we come back to the presence of tricin in dicots. As the paper in question notes, alfalfa (Medicago sativa) and its related M. truncatula, are rare dicots in possessing tricin in their lignins. The research groups involved have built upon substantial work on tricin in grasses, well covered in the paper by Lui et al., which has produced considerable insights into the pathways in grasses, and the genes/enzymes involved. The current paper presents a remarkable array of work aimed at elucidating the genes/enzymes involved in allowing Medicago to biosynthesize tricin and to use it in lignification. The paper details how the hydroxylase genes/enzymes appear to have evolved; these are crucial to hydroxylate and then methylate, that is, to methoxylate, the two carbons ortho to the B-ring phenol (and often, as with the monolignols, referred to as being meta to the 3-carbon aromatic sidechain) of the parent flavonoid naringenin to produce tricin as the ultimate product (Fig. 1). The authors have left essentially no question unaddressed or unanswered, and included approaches that might not have been required to produce an already compelling paper on a significant study, but add to the rigor and definitiveness of their findings. The paper itself should be consulted for the details because it is particularly well laid out and explained, and highlights are clearly made in the Summary section and in the carefully crafted headings in the main paper. In total, these findings reveal how Medicago has achieved the biosynthesis of tricin, including for its use in lignification, and how the process differs from, and is therefore evolutionarily independent of, that in the grasses. Incidentally, the authors are unconcerned about the ability of such phenolics to be ‘transported’ to the wall. As has been noted for a number of engineered products, or for those noncanonical monomers arising from truncation of the monolignol pathway and producing intermediates, or products therefrom, that enter into lignification, they ‘all’ make it to the wall even in newly created transgenics without the benefit of evolution. The logical conclusion is that transporters are either remarkably promiscuous or they are not needed at all. The case for passive transport of such compounds across membranes has recently been made (Vermaas et al., 2019). It only remains unfortunate that we cannot ask Medicago dicots, or the monocots for that matter, why they ‘thought’ it was advantageous to produce tricin! The ‘new’ hydroxylase genes/enzymes revealed in Lui et al. will likely have value as researchers seek to introduce efficient pathways for introducing tricin into plant lines that currently do not possess it or use it in their lignification, for the prospect of either (or both) improving biomass conversion ease by lowering the recalcitrance attributable to lignin and toward valorizing lignin. To the extent that tricin, or other valuable flavonoid precursors along the pathway, are recoverable from the polymer, the realization that such valuable components may be associated with the currently underutilized and undervalued lignin, and on a scale never previously imagined, provides new opportunities to valorize the lignin component of biomass in crops and trees destined for biofuels and commodity chemicals production. JR was supported by the DOE Great Lakes Bioenergy Research Center (DOE Office of Science BER DE-SC0018409). The background work on various developments in lignification was with valuable coworkers including Hoon Kim, Wu Lan, Fachuang Lu, Yuki Tobimatsu, Steve Karlen, Rebecca Smith, Yanding Li, Dharshana Padmakshan, John Grabber, and Ron Hatfield in my own lab or Center (at the time), and would not have been possible without outstanding collaborators including Jorge Rencoret, José Carlos del Río, Wout Boerjan, Rick Dixon, Fang Chen, Catherine Lapierre, Clint Chapple, Shawn Mansfield, Vincent Chiang, Ron Sederoff, Ruben Vanholme, Kris Morreel, Shinya Kajita, Laura Bartley, Chung-Jui Tsai, Gregg Beckham, John Sedbrook, Wilfred Vermerris, Shawn Kaeppler, Tom Elder, Curtis Wilkerson, and others." @default.
• W3048247841 created "2020-08-13" @default.
• W3048247841 creator A5046106815 @default.
• W3048247841 date "2020-08-10" @default.
• W3048247841 modified "2023-09-27" @default.
• W3048247841 title "Tricin and tricin‐lignins in Medicago versus in monocots" @default.
• W3048247841 cites W1508842329 @default.
• W3048247841 cites W1957226527 @default.
• W3048247841 cites W1980107437 @default.
• W3048247841 cites W1987446334 @default.
• W3048247841 cites W2015677629 @default.
• W3048247841 cites W2119273703 @default.
• W3048247841 cites W2159560715 @default.
• W3048247841 cites W2510796616 @default.
• W3048247841 cites W2531920443 @default.
• W3048247841 cites W2560253371 @default.
• W3048247841 cites W2623683946 @default.
• W3048247841 cites W2923078072 @default.
• W3048247841 cites W2936940452 @default.
• W3048247841 cites W2982300690 @default.
• W3048247841 cites W3008858267 @default.
• W3048247841 cites W3012341641 @default.
• W3048247841 doi "https://doi.org/10.1111/nph.16827" @default.
• W3048247841 hasPubMedCentralId "https://www.ncbi.nlm.nih.gov/pmc/articles/7540572" @default.
• W3048247841 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/32777096" @default.
• W3048247841 hasPublicationYear "2020" @default.
• W3048247841 type Work @default.
• W3048247841 sameAs 3048247841 @default.
• W3048247841 citedByCount "8" @default.
• W3048247841 countsByYear W30482478412021 @default.
• W3048247841 countsByYear W30482478412022 @default.
• W3048247841 countsByYear W30482478412023 @default.
• W3048247841 crossrefType "journal-article" @default.
• W3048247841 hasAuthorship W3048247841A5046106815 @default.
• W3048247841 hasBestOaLocation W30482478412 @default.
• W3048247841 hasConcept C178790620 @default.
• W3048247841 hasConcept C185592680 @default.
• W3048247841 hasConcept C2778004101 @default.
• W3048247841 hasConcept C2779054382 @default.
• W3048247841 hasConcept C2779545570 @default.
• W3048247841 hasConceptScore W3048247841C178790620 @default.
• W3048247841 hasConceptScore W3048247841C185592680 @default.
• W3048247841 hasConceptScore W3048247841C2778004101 @default.
• W3048247841 hasConceptScore W3048247841C2779054382 @default.
• W3048247841 hasConceptScore W3048247841C2779545570 @default.
• W3048247841 hasIssue "1" @default.
• W3048247841 hasLocation W30482478411 @default.
• W3048247841 hasLocation W30482478412 @default.
• W3048247841 hasLocation W30482478413 @default.
• W3048247841 hasOpenAccess W3048247841 @default.
• W3048247841 hasPrimaryLocation W30482478411 @default.
• W3048247841 hasRelatedWork W1531601525 @default.
• W3048247841 hasRelatedWork W2319480705 @default.
• W3048247841 hasRelatedWork W2384464875 @default.
• W3048247841 hasRelatedWork W2606230654 @default.
• W3048247841 hasRelatedWork W2607424097 @default.
• W3048247841 hasRelatedWork W2748952813 @default.
• W3048247841 hasRelatedWork W2899084033 @default.
• W3048247841 hasRelatedWork W2948807893 @default.
• W3048247841 hasRelatedWork W2778153218 @default.
• W3048247841 hasRelatedWork W2913248484 @default.
• W3048247841 hasVolume "228" @default.
• W3048247841 isParatext "false" @default.
• W3048247841 isRetracted "false" @default.
• W3048247841 magId "3048247841" @default.
• W3048247841 workType "article" @default.