Wiley Acta Medica Okayama 0140-7791 2026 Tripartite Interaction Between Penicillium pinophilum-Host Plants and CMV-Y: A Model for Endophyte-Mediated Viral Biocontrol EN Sarah R. Ibiang Group of Plant-Microbe Interactions, Institute of Plant Science and Resources, Okayama University Ivan Galis Group of Plant-Insect Interactions, Institute of Plant Science and Resources, Okayama University Hideki Kondo Group of Plant-Microbe Interactions, Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Group of Plant-Microbe Interactions, Institute of Plant Science and Resources, Okayama University Plant-fungus-virus tripartite interactions represent complex ecological systems in which mutualistic endophytes can influence host physiology, yet the molecular basis of endophyte-mediated defence remains poorly understood. Here, we demonstrate that the endophytic fungus Penicillium pinophilum EU0013 suppresses the yellow strain of cucumber mosaic virus (CMV-Y) in Solanum lycopersicum and Nicotiana benthamiana. CMV-Y infection induced pronounced oxidative and hormonal perturbations, which were mitigated by P. pinophilum colonisation. Endophyte-associated plants exhibited early accumulation of jasmonate intermediates, consistent with the activation of jasmonate signalling. This response promoted the degradation of jasmonate-ZIM-domain proteins and release of core JA-responsive transcription factors. Virus-induced gene silencing identified MYC2 as a key regulator required for endophyte-mediated antiviral protection, with WRKY17 contributing to defence modulation. In parallel, transcriptome analysis revealed the upregulation of a Dicer-like gene, indicating enhanced engagement of RNA silencing, a primary antiviral mechanism targeting viral RNA. This coordinated activation occurred alongside significant induction of pathogenesis-related proteins, particularly PR9, and improved control of reactive oxygen species. Salicylic acid-responsive defences showed a host-modulated pattern, with PR1 induced by CMV and PR2/PR5 preferentially enhanced in endophyte-associated plants. Collectively, these findings demonstrate that P. pinophilum enhances antiviral immunity through coordinated defence integration pathways, providing a framework for endophyte-based viral disease management. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0960-7412 121 5 2025 Spider mite tetranins elicit different defense responses in different host habitats e70046 EN Yukiko Endo Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science Miku Tanaka Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science Takuya Uemura Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science Kaori Tanimura Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science Yoshitake Desaki Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science Rika Ozawa Center for Ecological Research, Kyoto University Sara Bonzano Department of Life Sciences and Systems Biology, Plant Physiology Unit, University of Turin Massimo E. Maffei Department of Life Sciences and Systems Biology, Plant Physiology Unit, University of Turin Tomonori Shinya Institute of Plant Science and Resources (IPSR), Okayama University Ivan Galis Institute of Plant Science and Resources (IPSR), Okayama University Gen]ichiro Arimura Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science Spider mites (Tetranychus urticae) are a major threat to economically important crops. Here, we investigated the potential of tetranins, in particular Tet3 and Tet4, as T. urticae protein-type elicitors that stimulate plant defense. Truncated Tet3 and Tet4 proteins showed efficacy in activating the defense gene pathogenesis-related 1 (PR1) and inducing phytohormone production in leaves of Phaseolus vulgaris. In particular, Tet3 caused a drastically higher Ca2+ influx in leaves, but a lower reactive oxygen species (ROS) generation compared to other tetranins, whereas Tet4 caused a low Ca2+ influx and a high ROS generation in the host plants. Such specific and non-specific elicitor activities were examined by knockdown of Tet3 and Tet4 expressions in mites, confirming their respective activities and in particular showing that they function additively or synergistically to induce defense responses. Of great interest is the fact that Tet3 and Tet4 expression levels were higher in mites on their preferred host, P. vulgaris, compared to the levels in mites on the less-preferred host, Cucumis sativus, whereas Tet1 and Tet2 were constitutively expressed regardless of their host. Furthermore, mites that had been hosted on C. sativus induced lower levels of PR1 expression, Ca2+ influx and ROS generation, i.e., Tet3- and Tet4-responsive defense responses, in both P. vulgaris and C. sativus leaves compared to the levels induced by mites that had been hosted on P. vulgaris. Taken together, these findings show that selected tetranins respond to variable host cues that may optimize herbivore fitness by altering the anti-mite response of the host plant. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0040-5752 136 4 2023 FLOURY ENDOSPERM 6 mutations enhance the sugary phenotype caused by the loss of ISOAMYLASE1 in barley 94 EN Ryo Matsushima Institute of Plant Science and Resources, Okayama University Hiroshi Hisano Institute of Plant Science and Resources, Okayama University Ivan Galis Institute of Plant Science and Resources, Okayama University Satoko Miura Department of Biological Production, Akita Prefectural University Naoko Crofts Department of Biological Production, Akita Prefectural University Yuto Takenaka College of Life Sciences, Ritsumeikan University Naoko F. Oitome Department of Biological Production, Akita Prefectural University Takeshi Ishimizu College of Life Sciences, Ritsumeikan University Naoko Fujita Department of Biological Production, Akita Prefectural University Kazuhiro Sato Institute of Plant Science and Resources, Okayama University Starch is a biologically and commercially important glucose polymer synthesized by plants as semicrystalline starch granules (SGs). Because SG morphology affects starch properties, mutants with altered SG morphology may be useful in breeding crops with desirable starch properties, including potentially novel properties. In this study, we employed a simple screen for mutants with altered SG morphology in barley (Hordeum vulgare). We isolated mutants that formed compound SGs together with the normal simple SGs in the endosperm and found that they were allelic mutants of the starch biosynthesis genes ISOAMYLASE1 (HvISA1) and FLOURY ENDOSPERM 6 (HvFLO6), encoding starch debranching enzyme and CARBOHYDRATE-BINDING MODULE 48-containing protein, respectively. We generated the hvflo6 hvisa1 double mutant and showed that it had significantly reduced starch biosynthesis and developed shrunken grains. In contrast to starch, soluble ƒ¿-glucan, phytoglycogen, and sugars accumulated to higher levels in the double mutant than in the single mutants. In addition, the double mutants showed defects in SG morphology in the endosperm and in the pollen. This novel genetic interaction suggests that hvflo6 acts as an enhancer of the sugary phenotype caused by hvisa1 mutation. No potential conflict of interest relevant to this article was reported.

Taylor & Francis Ltd Acta Medica Okayama 1742-9145 18 1 2023 Identification of quantitative trait loci associated with sorghum susceptibility to Asian stem borer damage 2153182 EN Cyprian Osinde Institute of Plant Science and Resources, Okayama University Wataru Sakamoto Institute of Plant Science and Resources, Okayama University Hiromi Kajiya-Kanegae Graduate School of Agricultural and Life Sciences, The University of Tokyo Islam S. Sobhy Institute of Plant Science and Resources, Okayama University Arthur K. Tugume Department of Plant Science, Microbiology and Biotechnology Makerere University Anthony M. Nsubuga Department of Plant Science, Microbiology and Biotechnology Makerere University Ivan Galis Institute of Plant Science and Resources, Okayama University Sorghum (Sorghum bicolor (L.) Moench) is an important crop originated in Africa that shows susceptibility to herbivores. In this study, we identified two sorghum genotypes with highly contrasting levels of stem damage caused by the caterpillars of Asian stem borer (Ostrinia furnacalis Guenee). Recombinant inbred lines (RILs) from genetic cross between resistant (BTx623) and susceptible (NOG) sorghum were used to perform a quantitative trait locus (QTL) analysis in the field. Two major QTLs responsible for higher NOG infestation by stem borer in three independent field seasons were detected on chromosomes 7 and 9, interestingly in positions that overlapped with two major QTLs for plant height. As plant height and stem borer damage were highly correlated, we propose that sorghum height-associated morphological or physiological traits could be important for stem borer establishment and/or damage in sorghum. No potential conflict of interest relevant to this article was reported.

Oxford University Press Acta Medica Okayama 0022-0957 70 5 2019 Honeydew-associated microbes elicit defense responses against brown planthopper in rice 1683 1696 EN David Wari Institute of Plant Science and Resources, Okayama University Md Alamgir Kabir Institute of Plant Science and Resources, Okayama University Kadis Mujiono Institute of Plant Science and Resources, Okayama University Yuko Hojo Institute of Plant Science and Resources, Okayama University Tomonori Shinya Institute of Plant Science and Resources, Okayama University Akio Tani Institute of Plant Science and Resources, Okayama University Hiroko Nakatani Institute of Plant Science and Resources, Okayama University Ivan Galis Institute of Plant Science and Resources, Okayama University Feeding of sucking insects, such as the rice brown planthopper (Nilaparvata lugens; BPH), causes only limited mechanical damage on plants that is otherwise essential for injury-triggered defense responses against herbivores. In pursuit of complementary BPH elicitors perceived by plants, we examined the potential effects of BPH honeydew secretions on the BPH monocot host, rice (Oryza sativa). We found that BPH honeydew strongly elicits direct and putative indirect defenses in rice, namely accumulation of phytoalexins in the leaves, and release of volatile organic compounds from the leaves that serve to attract natural enemies of herbivores, respectively. We then examined the elicitor active components in the honeydew and found that bacteria in the secretions are responsible for the activation of plant defense. Corroborating the importance of honeydew-associated microbiota for induced plant resistance, BPHs partially devoid of their microbiota via prolonged antibiotics ingestion induced significantly less defense in rice relative to antibiotic-free insects applied to similar groups of plants. Our data suggest that rice plants may additionally perceive herbivores via their honeydew-associated microbes, allowing them to discriminate between incompatible herbivores\that do not produce honeydew\and those that are compatible and therefore dangerous. No potential conflict of interest relevant to this article was reported.