Jamonic acid carboxyl methyltransferase: a key enzyme for jasmonate-regulated plant responses

Choi, Yang-Do 서울대학교 농업개발연구소 2000 농업생명과학연구 Vol.4 No.-

Methy1 jasmonate is a plant volatile that acts as an important cellular regulator mediating diverse developmental processes and defense responses. We have cloned the novel gene JMT encoding a S-adenosy1-L-methionine: jasmonic acid carboxyl methyltransferase from Arabidopsis thaliana. Recombinant JMT protein expressed in E. coli catalyzed the formation of methyl jasmonate from jasmonic acid with Km value of 38.5 mM. JMT was not detected in young seedlings but expressed in rosettes, cauline leaves and developing flowers. In addition, expression of the gene was induced both locally and systemically by wounding or methyl jasmonate treatment. This result suggests that JMT can perceive and respond to local and systemic signals generated by external stimuli, and that the signals may include methyl jasmonate itself. Transgenic Arabidopsis overexpressing the JMT contained 3-fold elevated level of endogenous methyl jasmonate without altering jasmonic acid content. The transgenic plants exhibited constitutive expression of jasmonate-responsive genes including VSP and PDF1.2 Furthemore, the transgenic plants showed enhanced level of resistance against the virulent fungus Botrytis cinerea. Thus, our data suggest that the jasmonic acid carboxyl methyltransferase is a key enzyme for the jasmonate-regulated plant responses. Activation of JMT expression leads to production of methyl jasmonate that could act as an intracellular regulator, a diffusible intercellular signal transducer, and an airborne signal mediating intra-and inter- plant communications.

Transcriptional regulators of stamen development in Arabidopsis identified by transcriptional profiling

Mandaokar, Ajin,Thines, Bryan,Shin, Byongchul,Markus Lange, B.,Choi, Goh,Koo, Yeon J.,Yoo, Yung J.,Choi, Yang D.,Choi, Giltsu,Browse, John Blackwell Publishing Ltd 2006 The Plant journal Vol.46 No.6

<P>Summary</P><P>In Arabidopsis, jasmonate is required for stamen and pollen maturation. Mutants deficient in jasmonate synthesis, such as <I>opr3</I>, are male-sterile but become fertile when jasmonate is applied to developing flower buds. We have used ATH1 oligonucleotide arrays to follow gene expression in <I>opr3</I> stamens for 22 h following jasmonate treatment. In these experiments, a total of 821 genes were specifically induced by jasmonate and 480 genes were repressed. Comparisons with data from previous studies indicate that these genes constitute a stamen-specific jasmonate transcriptome, with a large proportion (70%) of the genes expressed in the sporophytic tissue but not in the pollen. Bioinformatics tools allowed us to associate many of the induced genes with metabolic pathways that are probably upregulated during jasmonate-induced maturation. Our pathway analysis led to the identification of specific genes within larger families of homologues that apparently encode stamen-specific isozymes. Extensive additional analysis of our dataset identified 13 transcription factors that may be key regulators of the stamen maturation processes triggered by jasmonate. Two of these transcription factors, MYB21 and MYB24, are the only members of subgroup 19 of the R2R3 family of MYB proteins. A <I>myb21</I> mutant obtained by reverse genetics exhibited shorter anther filaments, delayed anther dehiscence and greatly reduced male fertility. A <I>myb24</I> mutant was phenotypically wild-type, but production of a <I>myb21</I><I>myb24</I> double mutant indicated that introduction of the <I>myb24</I> mutation exacerbated all three aspects of the <I>myb21</I> phenotype. Exogenous jasmonate could not restore fertility to <I>myb21</I> or <I>myb21</I><I>myb24</I> mutant plants. Together with the data from transcriptional profiling, these results indicate that MYB21 and MYB24 are induced by jasmonate and mediate important aspects of the jasmonate response during stamen development.</P>

Cloning and characterization of jasmonic acid carboxyl methyltransferase genes

Choi, Yang Do 서울대학교 농업개발연구소 2001 농업생명과학연구 Vol.5 No.-

Methyl jasmonate is an important cellular regulator that mediates diverse developmental processes and defense responses. We cloned the novel genes JMT and NTR1 encoding S-adenosyl-L-methionine: jasmonic acid carboxyl methyltransferase from Arabidopsis thaliana and Brassica campestris L. ssp. perkinensis, respectively. Recombinant JMT and NTR1 proteins expressed in E. coli catalyzed the formation of methly jasmonate from jasmonic acid. Kinetic properties, thermal characteristics, optimal pH, and ion-dependency of the NTR1 activity were almost identical to those of Arabidopsis JMT, indicating that these two proteins are orthologues of each other. Transgenic Arabidopsis overexpressing the JMT contained elevated level of endogenous methyl jasmonate, and exhibited constitutive expression of jasmonate-responsive genes and enhanced level of resistance against a virulent fungus. Expression of these genes initiated and limited in developing flower, but propagated systemically, through phloem in vascular bundles, down along with the floral and main stems to reach to the primary root. Moreover, the genes were induced both locally and systemically by wounding or methyl jasmonate treatment. Expression pattern and function of the genes are consistent with previous observations of jasmonate distributions among developing tissues and of jasmonate-responsive defense responses, indicating that the gene activation is a key control point for the jasmonate-regulated responses. Our data suggests that JMT can perceive and respond to local and systemic signals generated during flowering process or by external stimuli, and that the signals may include methyl jasmonate itself. Thus, the gene activation leads to production of methyl jasmonate that could act as a diffusible intra- and inter-cellular signal transducer.

고려인삼(Panax Ginseng C.A. Meyer) 모상근으로부터 Ginsenosides 생산에 미치는 Jasmonic acid와 Methyl jasmonate의 영향

박효진,오승용,최경화,맹성주,윤의수,양덕춘 고려인삼학회 2000 Journal of Ginseng Research Vol.24 No.2

To elucidate the effects of jasmonic acid and methyl jasmonate on the production of ginsenosides and growth, ginseng hairy root KGHR-8 clone was cultured on the 1/2 MS medium without growth regulators, which was supplemented with of various concentrations jasmonic acid and methyl jasmonate and culture period. The highest growth rate was obtained when 1$\mu\textrm{m}$ jasmonic acid and methyl jasmorlate were treated. However, the growth was inhibited at more than 30$\mu\textrm{m}$ of concentration. Treatment with high concen Dation of jasmonic acid (10$\mu\textrm{m}$) and methyl jasmonate (50$\mu\textrm{m}$) increased the contents and productivity of ginsenosides reversion of the growth inhibition. The highest contents and productivity of ginsenosides were appeared at 4 weeks after onset of the treatment of jasmonic acid and at 3 weeks in the case of methyl jasmonate. 인삼모상근의 생장과 ginsenosides의 함량을 높이기 위하여 생장조절제가 첨가되지 않은 1/2 MS 배지에 jasmonic acid와 methyl jasmonate의 농도와 처리시기를 달리하여 인삼모상근 KGHR울 세포주를 배양하였다. 인삼모상근 생장은jasmonic acid와 methyl jasmonate 모두 1$\mu\textrm{m}$ 농도에서 가장 양호하였으며 30$\mu\textrm{m}$ 이상 농도가 증가할수록 모상근생장이 감소하였다. 그러나 생장이 낮았던 jasmonic acid 10$\mu\textrm{m}$ 처리구와 methyl jasmonate 50$\mu\textrm{m}$에서 ginsenosides 함량과 생산성이 더 높았다. 배양시기별로 jasmonic acid와 methyl jasmonate의 처리 효과는 jasmonic acid는 배양 후4주, methyl jasmonate는 3주에 처리하는 것이 ginsenosides의 함량과 생산성을 높이는데 효과적이었다.

Non-Specific Phytohormonal Induction of AtMYB44 and Suppression of Jasmonate-Responsive Gene Activation in Arabidopsis thaliana

Jung, Choon-Kyun,Shim, Jae-Sung,Seo, Jun-Sung,Lee, Han-Yong,Kim, Chung-Ho,Choi, Yang-Do,Cheong, Jong-Joo Korean Society for Molecular and Cellular Biology 2010 Molecules and cells Vol.29 No.1

The Arabidopsis thaliana transcription factor gene AtMYB44 was induced within 10 min by treatment with methyl jasmonate (MeJA). Wound-induced expression of the gene was observed in local leaves, but not in distal leaves, illustrating jasmonate-independent induction at wound sites. AtMYB44 expression was not abolished in Arabidopsis mutants insensitive to jasmonate (coi1), ethylene (etr1), or abscisic acid (abi3-1) when treated with the corresponding hormones. Moreover, various growth hormones and sugars also induced rapid AtMYB44 transcript accumulation. Thus, AtMYB44 gene activation appears to not be induced by any specific hormone. MeJA-induced activation of jasmonate-responsive genes such as JR2, VSP, LOXII, and AOS was attenuated in transgenic Arabidopsis plants overexpressing the gene (35S:AtMYB44), but significantly enhanced in atmyb44 knockout mutants. The 35S:MYB44 and atmyb44 plants did not show defectiveness in MeJA-induced primary root growth inhibition, indicating that the differences in jasmonate-responsive gene expression observed was not due to alterations in the jasmonate signaling pathway. 35S:AtMYB44 seedlings exhibited slightly elevated chlorophyll levels and less jasmonate-induced anthocyanin accumulation, demonstrating suppression of jasmonate-mediated responses and enhancement of ABA-mediated responses. These observations support the hypothesis of mutual antagonistic actions between jasmonate- and abscisic acid-mediated signaling pathways.

Non-Specific Phytohormonal Induction of AtMYB44 and Suppression of Jasmonate-Responsive Gene Activation in Arabidopsis thaliana

Choonkyun Jung,심재성,Jun Sung Seo,이한용,김정호,Yang Do Choi,정종주 한국분자세포생물학회 2010 Molecules and cells Vol.29 No.1

The Arabidopsis thaliana transcription factor gene At-MYB44 was induced within 10 min by treatment with methyl jasmonate (MeJA). Wound-induced expression of the gene was observed in local leaves, but not in distal leaves, illustrating jasmonate-independent induction at wound sites. AtMYB44 expression was not abolished in Arabidopsis mutants insensitive to jasmonate (coi1), eth-ylene (etr1), or abscisic acid (abi3-1) when treated with the corresponding hormones. Moreover, various growth hor-mones and sugars also induced rapid AtMYB44 transcript accumulation. Thus, AtMYB44 gene activation appears to not be induced by any specific hormone. MeJA-induced activation of jasmonate-responsive genes such as JR2, VSP, LOXII, and AOS was attenuated in transgenic Arabi-dopsis plants overexpressing the gene (35S:AtMYB44), but significantly enhanced in atmyb44 knockout mutants. The 35S:MYB44 and atmyb44 plants did not show defec-tiveness in MeJA-induced primary root growth inhibition, indicating that the differences in jasmonate-responsive gene expression observed was not due to alterations in the jasmonate signaling pathway. 35S:AtMYB44 seedlings exhibited slightly elevated chlorophyll levels and less jas-monate-induced anthocyanin accumulation, demonstrat-ing suppression of jasmonate-mediated responses and enhancement of ABA-mediated responses. These obser-vations support the hypothesis of mutual antagonistic actions between jasmonate- and abscisic acid-mediated signaling pathways.

Overexpression of jasmonic acid carboxyl methyltransferase increases tuber yield and size in transgenic potato

Sohn, Hwang-Bae,Lee, Han-Yong,Seo, Ju-Seok,Jung, Choon-Kyun,Jeon, Jae-Heung,Kim, Jeong-Han,Lee, Yin-Won,Lee, Jong-Seob,Cheong, Jong-Joo,Choi, Yang-Do The Korean Society of Plant Biotechnology 2011 Plant biotechnology reports Vol.5 No.1

Jasmonates control diverse plant developmental processes, such as seed germination, flower, fruit and seed development, senescence and tuberization in potato. To understand the role of methyl jasmonate (MeJA) in potato tuberization, the Arabidopsis JMT gene encoding jasmonic acid carboxyl methyltransferase was constitutively overexpressed in transgenic potato plants. Increases in tuber yield and size as well as in vitro tuberization frequency were observed in transgenic plants. These were correlated with JMT mRNA level-- the higher expression level, the higher the tuber yield and size. The levels of jasmonic acid (JA), MeJA and tuberonic acid (TA) were also higher than those in control plants. Transgenic plants also exhibited higher expression of jasmonate-responsive genes such as those for allene oxide cyclase (AOC) and proteinase inhibitor II (PINII). These results indicate that JMT overexpression induces jasmonate biosynthesis genes and thus JA and TA pools in transgenic potatoes. This results in enhanced tuber yield and size in transgenic potato plants.

Methyl Jasmonate: Behavioral and Molecular Implications in Neurological Disorders

Oritoke Modupe Aluko,Joy Dubem Iroegbu,Omamuyovwi Meashack Ijomone,Solomon Umukoro 대한정신약물학회 2021 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.19 No.2

Methyl jasmonate (MJ) is a derivative of the jasmonate family which is found in most tropical regions of the world and present in many fruits and vegetables such as grapevines, tomato, rice, and sugarcane. MJ is a cyclopentanone phytohormone that plays a vital role in defense against stress and pathogens in plants. This has led to its isolation from plants for studies in animals. Many of these studies have been carried out to evaluate its therapeutic effects on behavioral and neurochemical functions. It has however been proposed to have beneficial potential over a wide range of neurological disorders. Hence, this review aims to provide an overview of the neuroprotective properties of MJ and its probable mechanisms of ameliorating neurological disorders. The information used for this review was sourced from research articles and scientific databases using ‘methyl jasmonate’, ‘behavior’, ‘neuroprotection’, ‘neurodegenerative dis-eases’, and ‘mechanisms’ as search words. The review highlights its influences on behavioral patterns of anxiety, ag-gression, depression, memory, psychotic, and stress. The molecular mechanisms such as modulation of the antioxidant defense, inflammatory biomarkers, neurotransmitter regulation, and neuronal regeneration, underlying its actions in man-aging neurodegenerative diseases like Alzheimer’s and Parkinson’s diseases are also discussed. This review, therefore, provides a detailed evaluation of methyl jasmonate as a potential neuroprotective compound with the ability to modify behavioral and molecular biomarkers underlying neurological disorders. Hence, MJ could be modeled as a guided treat-ment for the management of brain diseases.

The Arabidopsis AtLEC Gene Encoding a Lectin-like Protein Is Up-Regulated by Multiple Stimuli Including Developmental Signal, Wounding, Jasmonate,Ethylene, and Chitin Elicitor

Seoung Hyun Lyou,Hyon Jin Park,Choonkyun Jung,Hwang Bae Sohn,이가람,김정호,김민균,최양도,정종주 한국분자세포생물학회 2009 Molecules and cells Vol.27 No.1

The Arabidopsis gene AtLEC (At3g15356) gene encodes a putative 30-kDa protein with a legume lectin-like domain. Likely to classic legume lectin family of genes, AtLEC is expressed in rosette leaves, primary inflorescences, and roots, as observed in Northern blot analysis. The accumulation of AtLEC transcript is induced very rapidly, within 30 min, by chitin, a fungal wall-derived oligosaccharide elictor of the plant defense response. Transgenic Arabidopsis carrying an AtLEC promoter-driven -glucuronidase (GUS) construct exhibited GUS activity in the leaf veins, secondary inflorescences, carpel heads, and silique receptacles, in which no expression could be seen in Northern blot analysis. This observation suggests that AtLEC expression is induced transiently and locally during developmental processes in the absence of an external signal such as chitin. In addition, mechanically wounded sites showed strong GUS activity, indicating that the AtLEC promoter responds to jasmonate. Indeed, methyl jasmonate and ethylene exposure induced AtLEC expression within 3-6 h. Thus, the gene appears to play a role in the jasmonate-/ethylene-responsive, in addition to the chitin-elicited, defense responses. However, chitin-induced AtLEC expression was also observed in jasmonate-insensitive (coi1) and ethylene-insensitive (etr1-1) Arabidopsis mutants. Thus, it appears that chitin promotes AtLEC expression via a jasmonate- and/or ethylene-independent pathway.

Transcriptome Analysis Reveals Molecular Mechanisms Underlying Methyl Jasmonate-mediated Biosynthesis of Protopanaxadiol-type Saponins in Panax notoginseng Leaves

Li Ying,Lin Yuan,Jia Bing,Chen Geng,Shi Huineng,Xu Rui,Li Xuejiao,Tang Junrong,Tang Qingyan,Zhang Guanghui,Yang Jianli,Fan Wei,Yang Shengchao 한국식물학회 2022 Journal of Plant Biology Vol.65 No.1

Methyl jasmonate (MeJA) has been widely used to improve the biosynthesis of secondary metabolites such as triterpenoid saponins in medicinal plants. However, the underlying molecular mechanisms remain poorly understood. Differing from roots that accumulate protopanaxatriol-type saponins, Panax notoginseng leaves with a lower biomass mainly contain protopanaxadiol (PPD)-type saponins. Therefore, it is interesting to explore whether MeJA can activate the biosynthesis of PPD-type saponins in P. notoginseng leaves. In this study, we found MeJA could effectively induce the accumulation of PPD-type saponins, including ginsenoside Rb1, Rc, Rb2, Rb3 and notoginsenoside Fa, Fe in P. notoginseng leaves based on a newly established high-performance liquid chromatography method. Transcriptome analysis showed that differentially expressed genes (DEGs) induced by MeJA were mainly enriched in “terpenoid backbone biosynthesis”, “biosynthesis of unsaturated fatty acids”, “sesquiterpenoid and triterpenoid biosynthesis”, “fatty acid metabolism”, and “phenylpropanoid biosynthesis”. Furthermore, the expression profile and quantitative real-time PCR analysis of DEGs showed that MeJA could positively induce the molecular response of endogenous jasmonic acid (JA) signaling pathway, and increased PPD-type saponins mediated by MeJA in P. notoginseng leaves may be related to the high expression of FPS, SS, SE, DS and UGTs, and the low expression of CYP716A53v2 and β-AS. The results provide a molecular understanding for MeJA-elicited biosynthesis of triterpenoid saponins and facilitate the further characterization of the genes responsible for biosynthesis of PPD-type saponins in P. notoginseng leaves.