岡山大学農学部Acta Medica Okayama0474-02549212003Possible Involvement of AAAG Motif and PsDof1 in Elicitor-Induced Gene Expression in Pea2126ENHikaruSekiMizuriMarutaniYoshishigeInagakiKazuhiroToyodaTomonoriShiraishiYukiIchinoseRecently, we, isolated cDNA clone, PsDof1, from clicitor-treated pea cDNA library. The putative gene product, a PsDof1, encodes DNA binding protein that specifically binds the DNA fragment containing AAAG core sequence. In this paper we report that GST-PsDof1 fusion protein specifically binds to the promoter region containing AAAG core sequence(s) of PsCHS1, one of the elicitor-inducible genes encoding chalcone synthase (CHS). Furthermore the addition of DNA fragment containing AAAG motif to the 35S minimal promoter provided the elicitor-responsibility in transient transfection assay using pea protoplasts. These results suggest that PsDof1 might be involved in defense responses by acitivating the transcription by a binding to AAAG core sequence in the promoter of the defense-related genes in pea.No potential conflict of interest relevant to this article was reported.Blackwell PublishingActa Medica Okayama1462-5814862006Identification of glycosylation genes and glycosylated amino acids of flagellin in Pseudomonas syringae pv. tabaci923938ENFumikoTaguchiKasumiTakeuchiEtsukoKatohKatsuyoshiMurataTomokoSuzukiMizuriMarutaniTakayukiKawasakiMinakoEguchiShizueKatohHanaekakuChihiroYasudaYoshishigeInagakiKazuhiroToyodaTomonoriShiraishiYukiIchinoseA glycosylation island is a genetic region required for glycosylation. The glycosylation island of flagellin in Pseudomonas syringae pv. tabaci 6605 consists of three orfs: orf1, orf2 and orf3. Orf1 and orf2 encode putative glycosyltransferases, and their deletion mutants, Delta orf1 and Delta orf2, exhibit deficient flagellin glycosylation or produce partially glycosylated flagellin respectively. Digestion of glycosylated flagellin from wild-type bacteria and non-glycosylated flagellin from Delta orf1 mutant using aspartic N-peptidase and subsequent HPLC analysis revealed candidate glycosylated amino acids. By generation of site-directed Ser/Ala-substituted mutants, all glycosylated amino acid residues were identified at positions 143, 164, 176, 183, 193 and 201. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) analysis revealed that each glycan was about 540 Da. While all glycosylation-defective mutants retained swimming ability, swarming ability was reduced in the Delta orf1, Delta orf2 and Ser/Ala-substituted mutants. All glycosylation mutants were also found to be impaired in the ability to adhere to a polystyrene surface and in the ability to cause disease in tobacco. Based on the predicted tertiary structure of flagellin, S176 and S183 are expected to be located on most external surface of the flagellum. Thus the effect of Ala-substitution of these serines is stronger than that of other serines. These results suggest that glycosylation of flagellin in P. syringae pv. tabaci 6605 is required for bacterial virulence. It is also possible that glycosylation of flagellin may mask elicitor function of flagellin molecule.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551022013岡山県の栽培圃場における植物生育促進菌の探索と同定16ENYasuoYamagiwaKazuhiroToyodaYoshishigeInagakiYukiIchinoseTomonoriShiraishiA plant growth-promoting fungus was isolated from an agricultural field in Okayama Prefecture, Japan. The strain FS2, which enhanced seed germination, root elongation and leaf growth of Brassica rapa var. perviridis, was identified as Talaromyces wortmannii based on ITS1 sequence and its morphology.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551022013β-caryophylleneの植物に対する生育促進作用 および耐病性増進作用の解析714ENYasuoYamagiwaKazuhiroToyodaYoshishigeInagakiYukiIchinoseMitsuroHyakumachiaTomonoriShiraishiA plant growth-promoting fungus, Talaromyces wortmannii strain FS2 was isolated from an agricultural field at Okayama Pref. FS2 enhanced seed germination, root elongation and leaf growth of Brassica rapa var perviridis (Komatsuna). Such plant growth-promoting effect was observed in the same sealed chamber where FS2 was cultured on PDA medium separated from seedlings, suggesting effective volatile compound(s). GC‒MS analysis showed that FS2 emitted at least seven terpenoids, of which a volatile was identified as β‒caryophyllene. β‒caryophyllene alone promoted the growth of cucumber, Nicotiana benthamiana and barley. Furthermore β‒caryophyllene increased the yield of cucumber fruits. Interestingly, we found that β‒caryophyllene conditioned these plants to be resistant to respective diseases caused by Colletotrichum orbiculare, Botrytis cinerea or Blumeria graminis f. sp hordei. The findings indicate that β‒caryophyllene has desirable dual features and therefore, it is available to cultivation of many crops.No potential conflict of interest relevant to this article was reported.Acta Medica Okayama1822007Elicitin-responsive lectin-like receptor kinase genes in BY-2 cells152159ENMichikoSasabeKanaNaitoHirokoSuenagaTakakoIkedaKazuhiroToyodaYoshishigeInagakiTomonoriShiraishiYukiIchinose<p>The inhibition of elicitor-induced plant defense responses by the protein kinase inhibitors K252a and staurosporine indicates that defense responses require protein phosphorylation. We isolated a cDNA clone encoding Nicotiana tabacum lectin-like receptor protein kinase 1 ( NtlecRK1), an elicitor-responsive gene; in tobacco bright yellow ( BY-2) cells by a differential display method. NtlecRK forms a gene family with at least three members in tobacco. All three NtlecRK genes potentially encode the N-terminal legume lectin domain, transmembrane domain and C-terminal Ser/Thr-type protein kinase domain. Green fluorescent protein ( GFP) fusion showed that the NtlecRK1 protein was located on the plasma membrane. In addition, NtlecRK1 and 3 were responsive to INF1 elicitin and the bacterial elicitor harpin. These results indicate that NtlecRKs are membrane-located protein kinases that are induced during defense responses in BY-2 cells.</p>
No potential conflict of interest relevant to this article was reported.Acta Medica Okayama27932008Modulation of defense signal transduction by flagellin-induced WRKY41 transcription factor in Arabidopsis thaliana303312ENKuniakiHigashiYasuhiroIshigaYoshishigeInagakiKazuhiroToyodaTomonoriShiraishiYukiIchinose<p>Flagellin, a component of the flagellar filament of Pseudomonas syringae pv. tabaci 6605 (Pta), induces hypersensitive reaction in its non-host Arabidopsis thaliana. We identified the WRKY41 gene, which belongs to a multigene family encoding WRKY plant-specific transcription factors, as one of the flagellin-inducible genes in A. thaliana. Expression of WRKY41 is induced by inoculation with the incompatible pathogen P. syringae pv. tomato DC3000 (Pto) possessing AvrRpt2 and the non-host pathogens Pta within 6-h after inoculation, but not by inoculation with the compatible Pto. Expression of WRKY41 was also induced by inoculation of A. thaliana with an hrp-type three secretion system (T3SS)-defective mutant of Pto, indicating that effectors produced by T3SS in the Pto wild-type suppress the activation of WRKY41. Arabidopsis overexpressing WRKY41 showed enhanced resistance to the Pto wild-type but increased susceptibility to Erwinia carotovora EC1. WRKY41-overexpressing Arabidopsis constitutively expresses the PR5 gene, but suppresses the methyl jasmonate-induced PDF1.2 gene expression. These results demonstrate that WRKY41 may be a key regulator in the cross talk of salicylic acid and jasmonic acid pathways.</p>
No potential conflict of interest relevant to this article was reported.