Article
Plant Sciences
Jiajun Huang, Rongsheng Wang, Qi Zhang, Chunli Wang, Tao Liang, Yasufumi Hikichi, Kouhei Ohnishi, Gaofei Jiang, Tao Guo, Yong Zhang
Summary: PhcB and PhcA in Ralstonia solanacearum control a quorum-sensing (QS) system that regulates the expression of about one third of all genes, including pathogenesis genes. In addition, we have discovered that PrhX is crucial for the invasion and growth of this bacterium in host plants.
MOLECULAR PLANT PATHOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Connor G. G. Hendrich, Alicia N. N. Truchon, Beth L. L. Dalsing, Caitilyn Allen
Summary: Ralstonia solancearum causes bacterial wilt disease on diverse plant hosts by invading through the roots and spreading through the xylem vessels. Nitric oxide (NO) contributes to the activation of the pathogen's virulence by inducing the expression of the T3SS regulator, hrpB, and upregulating the T3SS and effectors.
MOLECULAR PLANT-MICROBE INTERACTIONS
(2023)
Article
Agronomy
Qiao-Qiao Guo, Yu-Zhen Li, Hua-Bin Shi, Ao-Yun Yi, Xiao-Li Xu, Hai-Hong Wang, Xin Deng, Zhi-Bing Wu, Zi-Ning Cui
Summary: A series of mandelic acid derivatives containing 2-mercapto-1,3,4-thiazole moiety were synthesized as potential inhibitors of Ralstonia solanacearum type III secretion system (T3SS). Among them, compound F-24 significantly inhibited the transcription of hrpY gene and attenuated hypersensitive response (HR) without inhibiting bacterial growth. F-24 showed better inhibitory activity than previously reported inhibitors and had the potential to control R. solanacearum.
PEST MANAGEMENT SCIENCE
(2023)
Article
Biochemistry & Molecular Biology
Shen Cong, Jun-Zhou Li, Zheng-Zhong Xiong, Hai-Lei Wei
Summary: In this study, a pathogenic R. solanacearum strain named P380 was isolated from the tomato rhizosphere. Five out of 12 core T3Es of strain P380 were introduced into Pseudomonas syringae DC3000D36E separately to determine their functions in interacting with plants. The results showed that these five T3Es play diverse roles in plant-pathogen interactions.
JOURNAL OF GENETICS AND GENOMICS
(2023)
Article
Plant Sciences
Min Chen, Weiqi Zhang, Liangliang Han, Xuejuan Ru, Yuzhu Cao, Yasufumi Hikichi, Kouhei Ohnishi, Guanghui Pan, Yong Zhang
Summary: The CysB regulator was found to play essential roles in cysteine synthesis, T3SS gene expression, and pathogenicity of R. solanacearum.
MOLECULAR PLANT PATHOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Bingsen Wang, Tianjiu He, Xueao Zheng, Botao Song, Huilan Chen
Summary: The study revealed that T3 effectors of Ralstonia solanacearum can impact the abundance of immune-related proteins in potato roots in a redundant manner. Proteins such as miraculin, HBP2, and TOM20 contribute to immunity against the pathogen, while PP1 contributes to susceptibility. Interestingly, the downregulated proteins were not downregulated at the transcriptional level, indicating significant posttranscriptional regulation.
MOLECULAR PLANT-MICROBE INTERACTIONS
(2021)
Article
Plant Sciences
Jeffrey K. Schachterle, Qi Huang
Summary: This study investigated the cool-virulence mechanisms of Ralstonia solanacearum UW551 by generating transposon mutants and identifying genes related to reduced virulence at cooler temperatures. The effector gene RipS1 was found to play a role in cool-virulence and could potentially serve as a target for diagnostic tools specific to cool-virulent strains of R. solanacearum. These findings contribute to a better understanding of cool-virulence and the development of control strategies against this plant pathogen.
FRONTIERS IN PLANT SCIENCE
(2021)
Article
Microbiology
Qingshan Zhang, Bofan Wu, Liangliang Han, Duan Yu, Tao Liang, Yan Wang, Tao Guo
Summary: The shikimate pathway is crucial for the biosynthesis of aromatic amino acids in microorganisms. Ralstonia solanacearum relies on two 3-dehydroquinases, AroQ1 and AroQ2, for growth and pathogenicity in host plants.
FRONTIERS IN MICROBIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Ankita Pandey, Hayoung Moon, Sera Choi, Hayeon Yoon, Maxim Prokchorchik, Jay Jayaraman, Rajendran Sujeevan, Yu Mi Kang, Honour C. McCann, Cecile Segonzac, Chul Min Kim, Soon Ju Park, Kee Hoon Sohn
Summary: In this study, the R. solanacearum effector RipJ was identified as playing a pathogenic role in a specific eggplant species and triggering bacterial wilt resistance. Despite belonging to the YopJ family of acetyltransferases, RipJ does not require conserved residues in the acetyltransferase catalytic triad to induce immunity.
MOLECULAR PLANT-MICROBE INTERACTIONS
(2021)
Article
Microbiology
Yue Guan, Rongsheng Wang, Nan Chen, Yalan Zhu, Liangliang Han, Xinping Chen, Jing Li, Yong Zhang
Summary: This study reveals that ProA in Ralstonia solanacearum is responsible for the biosynthesis of proline from glutamate and can induce the expression of T3SS. ProA plays an important role in regulating T3SS expression and functions through the PrhG-HrpB pathway. Deletion of ProA impairs the pathogenicity of Ralstonia solanacearum in host plants.
FRONTIERS IN MICROBIOLOGY
(2022)
Review
Microbiology
Joren De Ryck, Petra Van Damme, Sofie Goormachtig
Summary: The type III secretion system (T3SS) is a well-studied pathogenicity determinant used by bacteria to translocate effectors (T3Es) into host cells for immune evasion and niche establishment. This article explores different approaches to functionally characterize T3Es, including host localization studies, virulence screenings, biochemical activity assays, and large-scale omics studies. Using Ralstonia solanacearum species complex (RSSC) as a case study, the advances in these methods and understanding of effector biology are discussed. Complementary data obtained from these methods offer crucial insights into the entire function of effectors and contribute to a better understanding of phytopathogens, presenting opportunities for tackling them.
FRONTIERS IN MICROBIOLOGY
(2023)
Article
Microbiology
Yong Yang, Ting Chen, Xiaoqiu Dai, Dong Yang, Yushuang Wu, Huilan Chen, Yixiong Zheng, Qingqing Zhi, Xiaorong Wan, Xiaodan Tan
Summary: This study analyzed the transcriptomic changes of resistant and susceptible peanut leaves infected with R. solanacearum, revealing the important roles of plant-pathogen interaction, plant hormone signal transduction, and MAPK signaling pathway in the peanut response to the bacteria. Three early molecular events induced by R. solanacearum infection were identified, providing new insights into enhancing bacterial wilt resistance in peanuts.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Microbiology
Yangchen Miao, Leilei Wu, Qi Xue, Qiuyan Zhang, Huasong Zou
Summary: Researchers have found that the type III effector protein RipAA of Ralstonia solanacearum GMI1000 plays a critical role in Nicotiana benthamiana. RipAA expression in the plant leads to the accumulation of hydrogen peroxide (H2O2) and degradation of genomic DNA, accompanied by a hypersensitive reaction. It also alters the expression of marker genes in the salicylic acid (SA) and jasmonic acid (JA) signaling pathways. RipAA interacts with the chloroplastic AtpB protein in N. benthamiana, and silencing of the atpB gene reduces the ability of RipAA to induce a hypersensitive response and a compatible interaction with GMI1000, while increasing sensitivity to bacterial wilt.
FRONTIERS IN MICROBIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Dong Cheng, Dan Zhou, Yudan Wang, Bingsen Wang, Qin He, Botao Song, Huilan Chen
Summary: This study identified RipV2 as a novel E3 ubiquitin ligase effector in R. solanacearum, which induces cell death and suppresses immune responses in host plants, affecting the plant-microbe interactions.
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
(2021)
Review
Microbiology
Kenji Kai
Summary: Ralstonia solanacearum species complex (RSSC) strains are devastating plant pathogens distributed worldwide. The primary cell density-dependent gene expression system in RSSC strains is phc quorum sensing (QS), which regulates the expression of about 30% of all genes. The specificity in generating and receiving its QS signal, but their signaling pathways might not differ significantly. This review discusses the genetic and biochemical factors involved in QS signal input, the regulatory network, and the interactions with soil fungi.
ANNUAL REVIEW OF MICROBIOLOGY
(2023)
Article
Plant Sciences
Min Chen, Weiqi Zhang, Liangliang Han, Xuejuan Ru, Yuzhu Cao, Yasufumi Hikichi, Kouhei Ohnishi, Guanghui Pan, Yong Zhang
Summary: The CysB regulator was found to play essential roles in cysteine synthesis, T3SS gene expression, and pathogenicity of R. solanacearum.
MOLECULAR PLANT PATHOLOGY
(2022)
Article
Plant Sciences
Kanako Inoue, Chika Takemura, Wakana Senuma, Hidefumi Maeda, Kenji Kai, Akinori Kiba, Kouhei Ohnishi, Masayuki Tsuzuki, Yasufumi Hikichi
Summary: In this study, the infection route of Ralstonia solanacearum strain OE1-1 in tomato roots was investigated. The strain first attaches to the meristematic and elongation zones of tomato roots and then colonizes the intercellular spaces between the epidermis and cortex. It further invades the cortical cells and forms biofilms to progress through the cortex and endodermis, eventually infecting the pericycle cells and xylem vessels. The secretion of quorum sensing-inducible plant cell wall-degrading enzymes via the type II secretion system is essential for infection.
JOURNAL OF PLANT RESEARCH
(2023)
Article
Plant Sciences
Mehbub Hasan, Akinori Kiba, Yasufumi Hikichi, Masayuki Tsuzuki, Kouhei Ohnishi
Summary: In this study, a new method for evaluating the pathogenicity of Ralstonia solanacearum in ginger using aseptically regenerated plants was developed. It was found that the type III secretion system of the pathogenic strain is crucial for its virulence. These findings contribute to a better understanding of the infection mechanism of Ralstonia solanacearum in ginger.
JOURNAL OF GENERAL PLANT PATHOLOGY
(2023)
Article
Plant Sciences
Masayuki Tsuzuki, Kanako Inoue, Akinori Kiba, Kouhei Ohnishi, Kenji Kai, Yasufumi Hikichi
Summary: The Gram-negative bacterium Ralstonia pseudosolanacearum strain OE1-1 attaches to tomato roots, activates quorum sensing, and forms biofilms to infect xylem vessels. Quorum sensing involves the induction and activation of the transcriptional regulator PhcA, and is associated with the production of secondary metabolites and exopolysaccharides. These components contribute to the positive feedback loop of quorum sensing.
PHYSIOLOGICAL AND MOLECULAR PLANT PATHOLOGY
(2023)
Article
Multidisciplinary Sciences
Akshay Sarkar, Jatindra N. Bhakta, Bubai Bhakta, Kouhei Ohnishi
Summary: The study focused on using Azolla pinnata and cattle waste to control CO2 emissions and global warming. It found that the maximum growth and CO2 sequestration of A. pinnata were achieved with 10% cow dung and 0.5% cow urine.
Article
Microbiology
Mehbub Hasan, Miho Satoh, Akinori Kiba, Yasufumi Hikichi, Kouhei Ohnishi
Summary: This study presents the complete genome sequences of Ralstonia solanacearum strains isolated from ginger plants. A total of 69, 64, 65, 69, 72, and 64 type III effector genes were identified from strains MAFF 211471, MAFF 211479, MAFF 211491, MAFF 301560, MAFF 241647, and MAFF 241648, respectively.
MICROBIOLOGY RESOURCE ANNOUNCEMENTS
(2023)
Article
Microbiology
Bubai Bhakta, Miho Satoh, Kouhei Ohnishi
Summary: We present the draft genome sequences of bacterial strains belonging to the genera Alteromonas and Tenacibaculum. Polysaccharide utilization loci (PULs) were found in all ulvan-utilizing strains. Comparison of the PULs will provide insights into the degradation pathway of ulvan.
MICROBIOLOGY RESOURCE ANNOUNCEMENTS
(2023)
Article
Plant Sciences
Chika Takemura, Wakana Senuma, Masayuki Tsuzuki, Yuki Terazawa, Kanako Inoue, Masanao Sato, Akinori Kiba, Kouhei Ohnishi, Kenji Kai, Yasufumi Hikichi
Summary: Research shows that the protein ChpA regulates QS-dependent genes and affects the behavior in host plant roots and virulence of pathogenic bacterium Ralstonia pseudosolanacearum OE1-1.
MOLECULAR PLANT PATHOLOGY
(2023)
Article
Plant Sciences
Jiajun Huang, Rongsheng Wang, Qi Zhang, Chunli Wang, Tao Liang, Yasufumi Hikichi, Kouhei Ohnishi, Gaofei Jiang, Tao Guo, Yong Zhang
Summary: PhcB and PhcA in Ralstonia solanacearum control a quorum-sensing (QS) system that regulates the expression of about one third of all genes, including pathogenesis genes. In addition, we have discovered that PrhX is crucial for the invasion and growth of this bacterium in host plants.
MOLECULAR PLANT PATHOLOGY
(2023)
Article
Horticulture
Bubai Bhakta, Shinzo Yamane, Jatindra Nath Bhakta, Kouhei Ohnishi
Summary: Slightly acidic electrolyzed water (SAEW) has strong bactericidal activity and is relatively safe. It can effectively kill bacteria, improve environmental conditions in the greenhouse, and does not affect plant growth.