Expression of Castanea crenata Allene Oxide Synthase in Arabidopsis Improves the Defense to Phytophthora cinnamomi

ABSTRACTAllene oxide synthase (AOS) is a key enzyme of the jasmonic acid (JA) signaling pathway. The AOS gene was previously found to be upregulated in an Asian chestnut species resistant to infection by the oomycete Phytophthora cinnamomi (Castanea crenata), while lower expression values were detected in the susceptible European chestnut (Castanea sativa). Here, we report a genetic and functional characterization of the C. crenata AOS (CcAOS) upon its heterologous gene expression in a susceptible ecotype of Arabidopsis thaliana, which contains a single AOS gene. It was found that Arabidopsis plants expressing CcAOS delay pathogen progression and exhibit more vigorous growth in its presence. They also show upregulation of jasmonic acid and salicylic acid-related genes. As in its native species, heterologous CcAOS localized to plastids, as revealed by confocal imaging of the CcAOS-eGFP fusion protein in transgenic Arabidopsis roots. This observation was confirmed upon transient expression in Nicotiana benthamiana leaf epidermal cells. To further confirm a specific role of CcAOS in the defense mechanism against the pathogen, we performed crosses between transgenic CcAOS plants and an infertile Arabidopsis AOS knockout mutant line. It was found that plants expressing CcAOS exhibit normal growth, remain infertile but are significantly more tolerant to the pathogen than wild type plants.Together, our results indicate that CcAOS is an important player in plant defense responses against oomycete infection and that its expression in susceptible varieties may be a valuable tool to mitigate biotic stress responses.One-sentence summaryHeterologous expression of the Castanea crenata allene oxide synthase gene in Arabidopsis thaliana improves the defense response to the pathogen Phytophthora cinnamomi.

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Expression of Castanea crenata Allene Oxide Synthase in Arabidopsis Improves the Defense to Phytophthora cinnamomi

Frontiers in Plant Science ◽

10.3389/fpls.2021.628697 ◽

2021 ◽

Vol 12 ◽

Author(s):

Susana Serrazina ◽

Helena Machado ◽

Rita Lourenço Costa ◽

Paula Duque ◽

Rui Malhó

Keyword(s):

Jasmonic Acid ◽

Stress Responses ◽

Phytophthora Cinnamomi ◽

Functional Characterization ◽

Defense Responses ◽

Confocal Imaging ◽

Allene Oxide ◽

Allene Oxide Synthase ◽

Castanea Crenata ◽

Oxide Synthase

Allene oxide synthase (AOS) is a key enzyme of the jasmonic acid (JA) signaling pathway. The AOS gene was previously found to be upregulated in an Asian chestnut species resistant to infection by the oomycete Phytophthora cinnamomi (Castanea crenata), while lower expression values were detected in the susceptible European chestnut (Castanea sativa). Here, we report a genetic and functional characterization of the C. crenata AOS (CcAOS) upon its heterologous gene expression in a susceptible ecotype of Arabidopsis thaliana, which contains a single AOS gene. It was found that Arabidopsis plants expressing CcAOS delay pathogen progression and exhibit more vigorous growth in its presence. They also show upregulation of jasmonic acid and salicylic acid-related genes. As in its native species, heterologous CcAOS localized to plastids, as revealed by confocal imaging of the CcAOS-eGFP fusion protein in transgenic Arabidopsis roots. This observation was confirmed upon transient expression in Nicotiana benthamiana leaf epidermal cells. To further confirm a specific role of CcAOS in the defense mechanism against the pathogen, we performed crosses between transgenic CcAOS plants and an infertile Arabidopsis AOS knockout mutant line. It was found that plants expressing CcAOS exhibit normal growth, remain infertile but are significantly more tolerant to the pathogen than wild type plants. Together, our results indicate that CcAOS is an important player in plant defense responses against oomycete infection and that its expression in susceptible varieties may be a valuable tool to mitigate biotic stress responses.

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Wounding stimulates ALLENE OXIDE SYNTHASE gene and increases the level of jasmonic acid in Ipomoea nil cotyledons

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.3491 ◽

2016 ◽

Vol 85 (1) ◽

Author(s):

Emilia Wilmowicz ◽

Agata Kućko ◽

Kamil Frankowski ◽

Barbara Zabrocka-Nowakowska ◽

Katarzyna Panek ◽

...

Keyword(s):

Jasmonic Acid ◽

Stress Responses ◽

Allene Oxide ◽

Allene Oxide Synthase ◽

Lipoxygenase Pathway ◽

Ipomoea Nil ◽

Evolutionarily Conserved ◽

Strong Stimulation ◽

Oxide Synthase

Allene oxide synthase (AOS) encodes the first enzyme in the lipoxygenase pathway, which is responsible for jasmonic acid (JA) formation. In this study we report the molecular cloning and characterization of InAOS from Ipomoea nil. The full-length gene is composed of 1662 bp and encodes for 519 amino acids. The predicted InAOS contains PLN02648 motif, which is evolutionarily conserved and characteristic for functional enzymatic proteins. We have shown that wounding led to a strong stimulation of the examined gene activity in cotyledons and an increase in JA level, which suggest that this compound may be a modulator of stress responses in I. nil.

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Functional Characterization of An Allene Oxide Synthase Involved in Biosynthesis of Jasmonic Acid and Its Influence on Metabolite Profiles and Ethylene Formation in Tea (Camellia sinensis) Flowers

International Journal of Molecular Sciences ◽

10.3390/ijms19082440 ◽

2018 ◽

Vol 19 (8) ◽

pp. 2440 ◽

Cited By ~ 5

Author(s):

Qiyuan Peng ◽

Ying Zhou ◽

Yinyin Liao ◽

Lanting Zeng ◽

Xinlan Xu ◽

...

Keyword(s):

Mass Spectrometry ◽

Jasmonic Acid ◽

Camellia Sinensis ◽

Allene Oxide ◽

Allene Oxide Synthase ◽

Tea Leaves ◽

Ethylene Formation ◽

Horticultural Crops ◽

Metabolite Profiles ◽

Oxide Synthase

Jasmonic acid (JA) is reportedly involved in the interaction between insects and the vegetative parts of horticultural crops; less attention has, however, been paid to its involvement in the interaction between insects and the floral parts of horticultural crops. Previously, we investigated the allene oxide synthase 2 (AOS2) gene that was found to be the only JA synthesis gene upregulated in tea (Camellia sinensis) flowers exposed to insect (Thrips hawaiiensis (Morgan)) attacks. In our present study, transient expression analysis in Nicotiana benthamiana plants confirmed that CsAOS2 functioned in JA synthesis and was located in the chloroplast membrane. In contrast to tea leaves, the metabolite profiles of tea flowers were not significantly affected by 10 h JA (2.5 mM) treatment as determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry, and gas chromatography-mass spectrometry. Moreover, JA treatment did not significantly influence ethylene formation in tea flowers. These results suggest that JA in tea flowers may have different functions from JA in tea leaves and other flowers.

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ALLENE OXIDE SYNTHASE and HYDROPEROXIDE LYASE, Two Non-Canonical Cytochrome P450s in Arabidopsis thaliana and Their Different Roles in Plant Defense

International Journal of Molecular Sciences ◽

10.3390/ijms20123064 ◽

2019 ◽

Vol 20 (12) ◽

pp. 3064 ◽

Cited By ~ 3

Author(s):

Sachin Rustgi ◽

Armin Springer ◽

ChulHee Kang ◽

Diter von Wettstein ◽

Christiane Reinbothe ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Plant Defense ◽

Metabolic Regulation ◽

Insect Pests ◽

Green Leaf Volatiles ◽

Hydroperoxide Lyase ◽

Allene Oxide ◽

Allene Oxide Synthase ◽

Cytochrome P450 Enzymes ◽

Oxide Synthase

The channeling of metabolites is an essential step of metabolic regulation in all living organisms. Multifunctional enzymes with defined domains for metabolite compartmentalization are rare, but in many cases, larger assemblies forming multimeric protein complexes operate in defined metabolic shunts. In Arabidopsis thaliana, a multimeric complex was discovered that contains a 13-lipoxygenase and allene oxide synthase (AOS) as well as allene oxide cyclase. All three plant enzymes are localized in chloroplasts, contributing to the biosynthesis of jasmonic acid (JA). JA and its derivatives act as ubiquitous plant defense regulators in responses to both biotic and abiotic stresses. AOS belongs to the superfamily of cytochrome P450 enzymes and is named CYP74A. Another CYP450 in chloroplasts, hydroperoxide lyase (HPL, CYP74B), competes with AOS for the common substrate. The products of the HPL reaction are green leaf volatiles that are involved in the deterrence of insect pests. Both enzymes represent non-canonical CYP450 family members, as they do not depend on O2 and NADPH-dependent CYP450 reductase activities. AOS and HPL activities are crucial for plants to respond to different biotic foes. In this mini-review, we aim to summarize how plants make use of the LOX2–AOS–AOC2 complex in chloroplasts to boost JA biosynthesis over volatile production and how this situation may change in plant communities during mass ingestion by insect pests.

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Allene oxide synthase, allene oxide cyclase and jasmonic acid levels in Lotus japonicus nodules

PLoS ONE ◽

10.1371/journal.pone.0190884 ◽

2018 ◽

Vol 13 (1) ◽

pp. e0190884 ◽

Cited By ~ 5

Author(s):

Anna Zdyb ◽

Marco G. Salgado ◽

Kirill N. Demchenko ◽

Wolfram G. Brenner ◽

Małgorzata Płaszczyca ◽

...

Keyword(s):

Jasmonic Acid ◽

Lotus Japonicus ◽

Allene Oxide ◽

Allene Oxide Synthase ◽

Allene Oxide Cyclase ◽

Oxide Synthase

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Synthesis of novel triazole derivatives as potent inhibitor of allene oxide synthase (CYP74A), a key enzyme in jasmonic acid biosynthesis

Journal of Pesticide Science ◽

10.1584/jpestics.d11-006 ◽

2012 ◽

Vol 37 (1) ◽

pp. 80-84 ◽

Cited By ~ 5

Author(s):

Keimei Oh ◽

Kouta Nakai ◽

Kazuhiro Yamada ◽

Yuko Yoshizawa

Keyword(s):

Jasmonic Acid ◽

Potent Inhibitor ◽

Allene Oxide ◽

Allene Oxide Synthase ◽

Acid Biosynthesis ◽

Triazole Derivatives ◽

Jasmonic Acid Biosynthesis ◽

Key Enzyme ◽

Oxide Synthase

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Inducible Overexpression of a Rice Allene Oxide Synthase Gene Increases the Endogenous Jasmonic Acid Level, PR Gene Expression, and Host Resistance to Fungal Infection

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-19-1127 ◽

2006 ◽

Vol 19 (10) ◽

pp. 1127-1137 ◽

Cited By ~ 210

Author(s):

Chuansheng Mei ◽

Min Qi ◽

Guangyao Sheng ◽

Yinong Yang

Keyword(s):

Gene Expression ◽

Jasmonic Acid ◽

Induced Resistance ◽

Defense Response ◽

Cytochrome P450 Enzyme ◽

Allene Oxide ◽

Allene Oxide Synthase ◽

Pathogen Infection ◽

Rice Plants ◽

Oxide Synthase

Many studies in dicotyledonous plants have shown that jasmonates, including jasmonic acid (JA) and methyl jasmonate, are important signal molecules involved in induced resistance to pathogen infection and insect herbivory. However, very little genetic and molecular evidence is available to demonstrate their role in host defense response of rice and other economically important monocot plants. In this study, we have shown that exogenous application of JA was able to activate defense gene expression and local induced resistance in rice seedlings against the rice blast fungus (Magnaporthe grisea). Furthermore, we have characterized a pathogen-inducible rice OsAOS2 gene (which encodes allene oxide synthase, a key enzyme in the JA biosynthetic pathway) and examined the role of endogenous JA in rice defense response through transgenic manipulation of the JA biosynthesis. Sequence analysis indicated that OsAOS2 contains four common domains of the cytochrome P450 enzyme, but does not have the signal peptide for chloroplast targeting. The basal level of OsAOS2 expression is very low in leaves but relatively high in the sheath, culm, and flower of rice plants. Interestingly, the expression of OsAOS2 in rice leaves can be induced significantly upon M. grisea infection. Transgenic rice lines carrying the OsAOS2 transgene under the control of a strong, pathogen-inducible PBZ1 promoter accumulated abundant OsAOS2 transcripts and higher levels of JA, especially after the pathogen infection. These transgenic lines also exhibited enhanced activation of pathogenesis-related (PR) genes such as PR1a, PR3, and PR5 and increased resistance to M. grisea infection. Our results suggest that JA plays a significant role in PR gene induction and blast resistance in rice plants.

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