scholarly journals Mechanistic basis for the evolution of chalcone synthase catalytic cysteine reactivity in land plants

2018 ◽  
Author(s):  
Geoffrey Liou ◽  
Ying-Chih Chiang ◽  
Yi Wang ◽  
Jing-Ke Weng
Keyword(s):  
Crystal Structures ◽  
Chalcone Synthase ◽  
Vascular Plant ◽  
Flavonoid Biosynthesis ◽  
Land Plants ◽  
Flowering Plant ◽  
Ecological Niches ◽  
Sulfinic Acid ◽  
Moss Species ◽  
Catalytic Cysteine

AbstractFlavonoids are important polyphenolic natural products, ubiquitous in land plants, that play diverse functions in plants’ survival in their ecological niches, including UV protection, pigmentation for attracting pollinators, symbiotic nitrogen fixation, and defense against herbivores. Chalcone synthase (CHS) catalyzes the first committed step in plant flavonoid biosynthesis and is highly conserved in all land plants. In several previously reported crystal structures of flowering plant CHSs, the catalytic cysteine is oxidized to sulfinic acid, indicating enhanced nucleophilicity in this residue associated with its increased susceptibility to oxidation. In this study, we report a set of new crystal structures of CHSs representing all five major lineages of land plants. We reveal that the structures of CHS from a lycophyte and a moss species preserve the catalytic cysteine in a reduced state, in contrast to the cysteine sulfinic acid seen in all euphyllophyte CHS structures. In vivo complementation, in vitro biochemical and mutagenesis analyses, as well as molecular dynamics simulations identify a set of residues that differ between basal-plant and euphyllophyte CHSs and modulate catalytic cysteine reactivity. We propose that the CHS active-site environment has evolved in euphyllophytes to further enhance the nucleophilicity of the catalytic cysteine since the divergence of euphyllophytes from other vascular plant lineages 400 million years ago. These changes in CHS could have contributed to the diversification of flavonoid biosynthesis in euphyllophytes, which in turn contributed to their dominance in terrestrial ecosystems.

scholarly journals Mechanistic basis for the evolution of chalcone synthase catalytic cysteine reactivity in land plants

2018 ◽  
Vol 293 (48) ◽  
pp. 18601-18612 ◽  
Author(s):  
Geoffrey Liou ◽  
Ying-Chih Chiang ◽  
Yi Wang ◽  
Jing-Ke Weng
Keyword(s):  
Chalcone Synthase ◽  
Land Plants ◽  
Catalytic Cysteine ◽  
Mechanistic Basis

Purification of Chalcone Synthase from Tulip Anthers and Comparison with the Synthase from Cosmos Petals

1981 ◽  
Vol 36 (1-2) ◽  
pp. 30-34 ◽  
Author(s):  
Rainer Sütfeld ◽  
Rolf Wiermann
Keyword(s):  
Chalcone Synthase ◽  
In Vitro Assay ◽  
Flavonoid Biosynthesis ◽  
Chalcone Isomerase ◽  
Gel Chromatography ◽  
Purification Procedure ◽  
Reaction Products ◽  
Complete Elimination ◽  
Vitro Assay

Abstract Chalcone synthase was isolated from both anthers of Tulipa cv. “Apeldoorn” and petals of Cosmos sulphureus Cav. After certain prepurification steps, the enzymes were further purified using gel chromatography on Sephadex G-200 followed by repeated hydroxylapatite absorption chromatography. Both the enzymes showed the same chromatographic properties. After gel chromatography as well as after the first hydroxylapatite fractionation, the reaction products appeared as flavanones. However, after the second hydroxylapatite step, production of chalcones was observed. Like the enzyme from tulip anthers, the synthase from Cosmos petals produced the correspondingly substituted chalcones when p-coumaroyl-CoA, caffeoyl-CoA and feruloyl-CoA, respectively, were used as substractes. In both the cases, the ratios of the different chalcones produced were found to be about the same. The appearance of chalcone synthesis in this in vitro assay is caused by the complete elimination of chalcone isomerase in the purification procedure. The importance of the isomerase for flavonoid biosynthesis, particularly in plant systems which are accumulating chalcones, is discussed.

Return of the megaherbs: plant colonisation of derelict ANARE station buildings on sub-Antarctic Heard Island

Polar Record ◽  
2004 ◽  
Vol 40 (3) ◽  
pp. 235-243 ◽  
Author(s):  
J. Whinam ◽  
P.M. Selkirk ◽  
A.J. Downing ◽  
Bruce Hull
Keyword(s):  
Plant Species ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Water Tank ◽  
Moss Species ◽  
Left Behind ◽  
Plant Colonisation ◽  
Vascular Plant Species ◽  
Heard Island ◽  
Antarctic Research

Buildings were constructed and artefacts left behind on sub-Antarctic Heard Island, associated with Antarctic research expeditions since 1926. Both bryophytes and vascular plants are colonising many parts of the now derelict buildings. On these structures and artefacts, the authors recorded four species of vascular plants out of the 11 that occur on Heard Island and nine species of mosses out of the 37 recorded from Heard Island. The vascular plant species most frequently recorded colonising structures and artefacts was Pringlea antiscorbutica (288 occurrences), with the area colonised varying from 0.3 cm2 to 430.0 cm2. Muelleriella crassifolia was the moss species that was most frequently recorded (14 occurrences), colonising areas from 2.1 cm2 to 12.9 cm2. The highest number of bryophyte species (seven) was recorded on the stone and cement of the ‘water tank.’ Pringlea antiscorbutica, Poa cookii, Azorella selago, Muelleriella crassifolia, Bryum dichotomum, Dicranoweisia brevipes and Schistidium apocarpum are all expected to continue to colonise the ANARE ruins, as well as areas that have become available since building removal and also possibly areas bared by further deglaciation.

scholarly journals O-methylated N-glycans Distinguish Mosses from Vascular Plants

Biomolecules ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 136
Author(s):  
David Stenitzer ◽  
Réka Mócsai ◽  
Harald Zechmeister ◽  
Ralf Reski ◽  
Eva L. Decker ◽  
...  
Keyword(s):  
Green Algae ◽  
Vascular Plants ◽  
Land Plants ◽  
Phylogenetic Relation ◽  
Complex Type ◽  
Animal Kingdom ◽  
Moss Species ◽  
First Finding ◽  
The Common ◽  
Terminal Mannose

In the animal kingdom, a stunning variety of N-glycan structures have emerged with phylogenetic specificities of various kinds. In the plant kingdom, however, N-glycosylation appears to be strictly conservative and uniform. From mosses to all kinds of gymno- and angiosperms, land plants mainly express structures with the common pentasaccharide core substituted with xylose, core α1,3-fucose, maybe terminal GlcNAc residues and Lewis A determinants. In contrast, green algae biosynthesise unique and unusual N-glycan structures with uncommon monosaccharides, a plethora of different structures and various kinds of O-methylation. Mosses, a group of plants that are separated by at least 400 million years of evolution from vascular plants, have hitherto been seen as harbouring an N-glycosylation machinery identical to that of vascular plants. To challenge this view, we analysed the N-glycomes of several moss species using MALDI-TOF/TOF, PGC-MS/MS and GC-MS. While all species contained the plant-typical heptasaccharide with no, one or two terminal GlcNAc residues (MMXF, MGnXF and GnGnXF, respectively), many species exhibited MS signals with 14.02 Da increments as characteristic for O-methylation. Throughout all analysed moss N-glycans, the level of methylation differed strongly even within the same family. In some species, methylated glycans dominated, while others had no methylation at all. GC-MS revealed the main glycan from Funaria hygrometrica to contain 2,6-O-methylated terminal mannose. Some mosses additionally presented very large, likewise methylated complex-type N-glycans. This first finding of the methylation of N-glycans in land plants mirrors the presumable phylogenetic relation of mosses to green algae, where the O-methylation of mannose and many other monosaccharides is a common trait.

Botanical Identity of Seasonal Flowering Plants Available and Maintained in the Home Gardens of District Nainital, Uttarakhand

2016 ◽  
Vol 23 (2) ◽  
pp. 89-102
Author(s):  
Kuldeep Negi ◽  
Vandana Tiwari ◽  
Puran Mehta ◽  
Rajni Rawat ◽  
Saraswati Ojha ◽  
...  
Keyword(s):  
Economic Status ◽  
Plant Genetic Resources ◽  
Geographical Area ◽  
Flowering Plants ◽  
Home Gardens ◽  
Flowering Plant ◽  
Ecological Niches ◽  
Wide Range ◽  
Seasonal Flowering ◽  
Flowering Plant Species

Uttarakhand is a store house of plant genetic resources of several crop groups including ornamentals and seasonal flowering plant species. A wide range of seasonal flowering plants are being grown in the region because of its various and favourable agro-geo climatic zones. Ornamental plant enhances aesthetic value of our environment. There are 8 developmental blocks and 1082 villages in district Nainital of Uttarakhand. Nainital district, is a part of Kumaun region of Uttarakhand. It lies between 29?0.1' to 29?36' 21'' N latitude and 78?50' 53'' to 80?06' E longitude. More than 7.62 lakh population reside in 4064 km2 of geographical area of district Nainital. The district falls under sub-tropical to temperate zones. During the course of field survey (2013-2015), we came across wide range of seasonal flowering plants mostly belong to exotic origin being grown in the home gardens of natives of the region situated in different agro-ecological niches. The present study highlighted a total of 150 seasonal flowering plants with 120 genera belonging to 50 families. These were arranged alphabetically with botanical names followed by vernacular and trade name, family, origin or native place, nature, season with appropriate remarks of variation in shape, size and colour, method of propagation with economic status.

Enzymatic Synthesis of 4′-and 3′, 4′ -Hydroxylated Flavanones and Flavones with Flower Extracts of Sinningia cardinalis

1987 ◽  
Vol 42 (11-12) ◽  
pp. 1193-1199 ◽  
Author(s):  
K. Stich ◽  
G. Forkmann
Keyword(s):  
Enzymatic Synthesis ◽  
Microsomal Fraction ◽  
Chalcone Synthase ◽  
Condensation Reaction ◽  
Flavonoid Biosynthesis ◽  
Hydroxylase Activity ◽  
Key Enzyme ◽  
Flavone Synthase ◽  
Flavone Synthase Ii ◽  
Cytochrome P 450

Flowers of Sinningia (syn. Rechsteineria) cardinalis contain glycosides of the flavones apigenin (4′-OH) and luteolin (3′,4′-OH) respectively, and of the related 3-deoxyanthocyanidins apigeninidin and luteolinidin. Studies on substrate specificity of the key enzyme of flavonoid biosynthesis, chalcone synthase, revealed that the 3′,4′-hydroxylated flavonoids are formed by hydroxylation of flavonoid compounds rather than by incorporation of caffeoyl-CoA into the flavonoid skeleton during the condensation reaction. In fact, flavonoid 3′-hydroxylase activity could be demonstrat­ed in the microsomal fraction of the flower extracts. The enzyme catalyses hydroxylation of naringenin and apigenin in the 3′-position to eriodictyol and luteolin, respectively, with NADPH as cofactor. Besides flavanone 3′-hydroxylase a further NADPH-dependent enzyme activity (flavone synthase II) was observed in the microsomal fraction catalysing the oxidation of naringenin to apigenin and of eriodictyol to luteolin. The Cytochrome P-450 inhibitor ancymidol was found to abolish completely flavone synthase II activity, whereas flavonoid 3′-hydroxylase activity was not impaired.

scholarly journals The dawn of symbiosis between plants and fungi

2011 ◽  
Vol 7 (4) ◽  
pp. 574-577 ◽  
Author(s):  
Martin I. Bidartondo ◽  
David J. Read ◽  
James M. Trappe ◽  
Vincent Merckx ◽  
Roberto Ligrone ◽  
...  
Keyword(s):  
Vascular Plant ◽  
Land Plants ◽  
Evolutionary Trees ◽  
Early Devonian ◽  
Present Evidence ◽  
Plant Fossils ◽  
Biological Innovations ◽  
New Hypothesis ◽  
Colonization Of Land ◽  
Early Land

The colonization of land by plants relied on fundamental biological innovations, among which was symbiosis with fungi to enhance nutrient uptake. Here we present evidence that several species representing the earliest groups of land plants are symbiotic with fungi of the Mucoromycotina. This finding brings up the possibility that terrestrialization was facilitated by these fungi rather than, as conventionally proposed, by members of the Glomeromycota. Since the 1970s it has been assumed, largely from the observation that vascular plant fossils of the early Devonian (400 Ma) show arbuscule-like structures, that fungi of the Glomeromycota were the earliest to form mycorrhizas, and evolutionary trees have, until now, placed Glomeromycota as the oldest known lineage of endomycorrhizal fungi. Our observation that Endogone -like fungi are widely associated with the earliest branching land plants, and give way to glomeromycotan fungi in later lineages, raises the new hypothesis that members of the Mucoromycotina rather than the Glomeromycota enabled the establishment and growth of early land colonists.

Diverse chalcone synthase superfamily enzymes from the most primitive vascular plant, Psilotum nudum

Planta ◽  
2001 ◽  
Vol 214 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Yasuyo Yamazaki ◽  
Dae-Yeon Suh ◽  
Worapan Sitthithaworn ◽  
Kazuhiko Ishiguro ◽  
Yukie Kobayashi ◽  
...  
Keyword(s):  
Chalcone Synthase ◽  
Vascular Plant ◽  
Psilotum Nudum ◽  
Chalcone Synthase Superfamily

Evolution of nitrogen-fixing symbioses

1985 ◽  
Vol 85 (3-4) ◽  
pp. 215-237 ◽  
Author(s):  
J. I. Sprent ◽  
J. A. Raven
Keyword(s):  
Root Nodules ◽  
Land Plants ◽  
Oxygenic Photosynthesis ◽  
Ecological Niches ◽  
Energy Costs ◽  
Nitrogen Fixing ◽  
Infection Structure ◽  
Combined Nitrogen ◽  
High Level ◽  
Biological Nitrogen

SynopsisBecause of both the energy costs and the slowness of the reactions of the nitrogenase complex compared with those involving some form of combined nitrogen (oxidised or reduced), we argue that the evolution of nitrogen-fixing organisms required an environment which was very limited in combined nitrogen. This is thought to have occurred after phototrophy evolved, but before water was used as a hydrogen donor (and therefore oxygen was present in the atmosphere). After oxygenic photosynthesis evolved, the need for a high level of biological nitrogen-fixation remained, since abiotic inputs were insufficient to keep pace with the rapidly evolving biomass (flora and fauna). Symbiotic fixation probably first evolved in the form of casual associations between cyanobacteria and most other groups of plants. By inhabiting the sporophytic generation of evolving land plants (cycads in particular), protection against nitrogenase-inactivating oxygen and a more desiccating environment was achieved simultaneously.We envisage nodulated plants arising by the transfer ofnifgenes into tumour-forming bacteria. In the case of legumes, these would be ancestors of extant agrobacteria, which gain entry into their hostsviawounds. Co-evolution of symbionts from nitrogen-fixing tumours has taken several routes, leading to extant nodules differing in mode of infection, structure and physiology. Evolution towards optimisation of oxygen usage is continuing.Nitrogen-fixing symbiosis in animal systems is only advantageous in specialised ecological niches in which wood is the sole dietary intake. In the case of shipworms, the symbiosis has many of the advanced features associated with nitrogen fixing root nodules.

Sign in / Sign up

Export Citation Format

Share Document