scholarly journals PBS3 and EPS1 complete salicylic acid biosynthesis from isochorismate in Arabidopsis

2019 ◽  
Author(s):  
Michael P. Torrens-Spence ◽  
Anastassia Bobokalonova ◽  
Valentina Carballo ◽  
Christopher M. Glinkerman ◽  
Tomáš Pluskal ◽  
...  

AbstractSalicylic acid (SA) is an important phytohormone mediating both local and systemic defense responses in plants. Despite over half a century of research, how plants biosynthesize SA remains unresolved. In Arabidopsis, a major part of SA is derived from isochorismate, a key intermediate produced by the isochorismate synthase (ICS), which is reminiscent of SA biosynthesis in bacteria. Whereas bacteria employ an isochorismate pyruvate lyase (IPL) that catalyzes the turnover of isochorismate to pyruvate and SA, plants do not contain an IPL ortholog and generate SA from isochorismate through an unknown mechanism. Combining genetic and biochemical approaches, we delineated the SA biosynthetic pathway downstream of isochorismate in Arabidopsis. We show that PBS3, a GH3 acyl adenylase-family enzyme important for SA accumulation, catalyzes ATP- and Mg2+-dependent conjugation of L-glutamate primarily to the 8-carboxyl of isochorismate and yields the key SA biosynthetic intermediate isochorismoyl-glutamate A. Moreover, EPS1, a BAHD acyltransferase-family protein with previously implicated role in SA accumulation upon pathogen attack, harbors a noncanonical active site and an unprecedented isochorismoyl-glutamate A pyruvoyl-glutamate lyase (IPGL) activity that produces SA from the isochorismoyl-glutamate A substrate. Together, PBS3 and EPS1 form a two-step metabolic pathway to produce SA from isochorismate in Arabidopsis, which is distinct from how SA is biosynthesized in bacteria. This study closes a major knowledge gap in plant SA metabolism and would help develop new strategies for engineering disease resistance in crop plants.

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 705
Author(s):  
Awdhesh Kumar Mishra ◽  
Kwang-Hyun Baek

Salicylic acid (SA) is an active secondary metabolite that occurs in bacteria, fungi, and plants. SA and its derivatives (collectively called salicylates) are synthesized from chorismate (derived from shikimate pathway). SA is considered an important phytohormone that regulates various aspects of plant growth, environmental stress, and defense responses against pathogens. Besides plants, a large number of bacterial species, such as Pseudomonas, Bacillus, Azospirillum, Salmonella, Achromobacter, Vibrio, Yersinia, and Mycobacteria, have been reported to synthesize salicylates through the NRPS/PKS biosynthetic gene clusters. This bacterial salicylate production is often linked to the biosynthesis of small ferric-ion-chelating molecules, salicyl-derived siderophores (known as catecholate) under iron-limited conditions. Although bacteria possess entirely different biosynthetic pathways from plants, they share one common biosynthetic enzyme, isochorismate synthase, which converts chorismate to isochorismate, a common precursor for synthesizing SA. Additionally, SA in plants and bacteria can undergo several modifications to carry out their specific functions. In this review, we will systematically focus on the plant and bacterial salicylate biosynthesis and its metabolism.


2016 ◽  
Vol 212 (3) ◽  
pp. 627-636 ◽  
Author(s):  
M. B. Shine ◽  
Jung-Wook Yang ◽  
Mohamed El-Habbak ◽  
Padmaja Nagyabhyru ◽  
Da-Qi Fu ◽  
...  

2012 ◽  
Vol 71 (1) ◽  
pp. 135-146 ◽  
Author(s):  
Sun-Mee Choi ◽  
Hae-Ryong Song ◽  
Soon-Ki Han ◽  
Muho Han ◽  
Chi-Yeol Kim ◽  
...  

2021 ◽  
Author(s):  
Michael P. Torrens-Spence ◽  
Tianjie Li ◽  
Ziqi Wang ◽  
Christopher M. Glinkerman ◽  
Jason O. Matos ◽  
...  

AbstractUnique to plants in the Brassicaceae family, the production of the plant defense hormone salicylic acid (SA) from isochorismate is accelerated by an evolutionarily young isochorismoyl-glutamate pyruvoyl-glutamate lyase, EPS1, which belongs to the BAHD acyltransferase protein family. Here, we report the crystal structures of apo and substrate-analog-bound EPS1 from Arabidopsis thaliana. Assisted by microsecond molecular dynamics simulations, we uncover a unique pericyclic rearrangement lyase mechanism facilitated by the active site of EPS1. We reconstitute the isochorismate-derived pathway of SA biosynthesis in Saccharomyces cerevisiae, which serves as an in vivo platform that helps identify active-site residues critical for EPS1 activity. This study describes the birth of a new catalyst in plant phytohormone biosynthesis by reconfiguring the ancestral active site of a progenitor enzyme to catalyze alternative reaction.One sentence summaryBy reconfiguring the active site of a progenitor acyltransferase-fold, EPS1 acquired the unique, evolutionarily new lyase activity that accelerates phytohormone salicylic acid production in Brassicaceae plants.


2001 ◽  
Vol 125 (1) ◽  
pp. 318-328 ◽  
Author(s):  
Julie Chong ◽  
Marie-Agnès Pierrel ◽  
Rossitza Atanassova ◽  
Danièle Werck-Reichhart ◽  
Bernard Fritig ◽  
...  

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhenyu Zhang ◽  
Pengfu Liu ◽  
Weike Su ◽  
Huawei Zhang ◽  
Wenqian Xu ◽  
...  

AbstractTrans-4-hydroxy-l-proline is an important amino acid that is widely used in medicinal and industrial applications, particularly as a valuable chiral building block for the organic synthesis of pharmaceuticals. Traditionally, trans-4-hydroxy-l-proline is produced by the acidic hydrolysis of collagen, but this process has serious drawbacks, such as low productivity, a complex process and heavy environmental pollution. Presently, trans-4-hydroxy-l-proline is mainly produced via fermentative production by microorganisms. Some recently published advances in metabolic engineering have been used to effectively construct microbial cell factories that have improved the trans-4-hydroxy-l-proline biosynthetic pathway. To probe the potential of microorganisms for trans-4-hydroxy-l-proline production, new strategies and tools must be proposed. In this review, we provide a comprehensive understanding of trans-4-hydroxy-l-proline, including its biosynthetic pathway, proline hydroxylases and production by metabolic engineering, with a focus on improving its production.


1995 ◽  
Vol 92 (10) ◽  
pp. 4134-4137 ◽  
Author(s):  
Z. Chen ◽  
J. Malamy ◽  
J. Henning ◽  
U. Conrath ◽  
P. Sanchez-Casas ◽  
...  

2018 ◽  
Vol 19 (11) ◽  
pp. 3519 ◽  
Author(s):  
Agustina Bernal-Vicente ◽  
Daniel Cantabella ◽  
Cesar Petri ◽  
José Hernández ◽  
Pedro Diaz-Vivancos

Salinity is considered as one of the most important abiotic challenges that affect crop productivity. Plant hormones, including salicylic acid (SA), are key factors in the defence signalling output triggered during plant responses against environmental stresses. We have previously reported in peach a new SA biosynthetic pathway from mandelonitrile (MD), the molecule at the hub of the cyanogenic glucoside turnover in Prunus sp. In this work, we have studied whether this new SA biosynthetic pathway is also present in plum and the possible role this pathway plays in plant plasticity under salinity, focusing on the transgenic plum line J8-1, which displays stress tolerance via an enhanced antioxidant capacity. The SA biosynthesis from MD in non-transgenic and J8-1 micropropagated plum shoots was studied by metabolomics. Then the response of J8-1 to salt stress in presence of MD or Phe (MD precursor) was assayed by measuring: chlorophyll content and fluorescence parameters, stress related hormones, levels of non-enzymatic antioxidants, the expression of two genes coding redox-related proteins, and the content of soluble nutrients. The results from in vitro assays suggest that the SA synthesis from the MD pathway demonstrated in peach is not clearly present in plum, at least under the tested conditions. Nevertheless, in J8-1 NaCl-stressed seedlings, an increase in SA was recorded as a result of the MD treatment, suggesting that MD could be involved in the SA biosynthesis under NaCl stress conditions in plum plants. We have also shown that the plum line J8-1 was tolerant to NaCl under greenhouse conditions, and this response was quite similar in MD-treated plants. Nevertheless, the MD treatment produced an increase in SA, jasmonic acid (JA) and reduced ascorbate (ASC) contents, as well as in the coefficient of non-photochemical quenching (qN) and the gene expression of Non-Expressor of Pathogenesis-Related 1 (NPR1) and thioredoxin H (TrxH) under salinity conditions. This response suggested a crosstalk between different signalling pathways (NPR1/Trx and SA/JA) leading to salinity tolerance in the transgenic plum line J8-1.


2013 ◽  
Vol 451 (2) ◽  
pp. 277-288 ◽  
Author(s):  
Sarah Schlosser ◽  
David Leitsch ◽  
Michael Duchêne

Entamoeba histolytica, the causative agent of amoebiasis, possesses the dithiol-containing redox proteins Trx (thioredoxin) and TrxR (Trx reductase). Both proteins were found to be covalently modified and inactivated by metronidazole, a 5-nitroimidazole drug that is commonly used to treat infections with microaerophilic protozoan parasites in humans. Currently, very little is known about enzymes and other proteins participating in the Trx-dependent redox network of the parasite that could be indirectly affected by metronidazole treatment. On the basis of the disulfide/dithiol-exchange mechanism we constructed an active-site mutant of Trx, capable of binding interacting proteins as a stable mixed disulfide intermediate to screen the target proteome of Trx in E. histolytica. By applying Trx affinity chromatography, two-dimensional gel electrophoresis and MS, peroxiredoxin and 15 further potentially redox-regulated proteins were identified. Among them, EhSat1 (E. histolytica serine acetyltransferase-1), an enzyme involved in the L-cysteine biosynthetic pathway, was selected for detailed analysis. Binding of Trx to EhSat1 was verified by Far-Western blot analysis. Trx was able to restore the activity of the oxidatively damaged EhSat1 suggesting that the TrxR/Trx system protects sensitive proteins against oxidative stress in E. histolytica. Furthermore, the activity of peroxiredoxin, which is dependent on a functioning TrxR/Trx system, was strongly reduced in metronidazole-treated parasites.


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