Microbiology Spectrum
·
2024
·
IF 3.7
Yun Li,Ruifeng Ma,Chenying Gao,Ziyi Li,Yongqin Zheng,Fang Fang,Cheng Wang,Guohua Li,Xiaozhen Du,Changbao Xu,Meirong Xu,Rui Liu,Xiaoling Deng,Zheng Zheng
“Candidatus Liberibacter asiaticus” (CLas), the causal agent of citrus Huanglongbing (HLB), is able to multiply to a high abundance in citrus fruit pith. However, little is known about the biological processes and phytochemical substances that are vital for CLas colonization and growth in fruit pith. In this study, CLas-infected fruit pith of three citrus cultivars (“Shatangju” mandarin, “Guanxi” pomelo, and “Shatian” pomelo) exhibiting different tolerance to CLas were collected and used for dual RNA-Seq and untargeted metabolome analysis. Comparative transcriptome analysis found that the activation of the CLas noncyclic TCA pathway and pathogenic-related effectors could contribute to the colonization and growth of CLas in fruit pith. The pre-established Type 2 prophage in the CLas genome and the induction of its CRISPR/cas system could enhance the phage resistance of CLas and, in turn, facilitate CLas population growth in fruit pith. CLas infection caused the accumulation of amino acids that were correlated with tolerance to CLas. The accumulation of most sugars and organic acids in CLas-infected fruit pith, which could be due to the phloem blockage caused by CLas infection, was thought to be beneficial for CLas growth in localized phloem tissue. The higher levels of flavonoids and terpenoids in the fruit pith of CLas-tolerant cultivars, particularly those known for their antimicrobial properties, could hinder the growth of CLas. This study advances our understanding of CLas multiplication in fruit pith and offers novel insight into metabolites that could be responsible for tolerance to CLas or essential to CLas population growth.
研究领域:
植物病理学
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分子生物学
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代谢组学
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转录组学
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DOI
PubMed
高影响因子
PHYTOPATHOLOGY
·
2024
·
IF 2.6
Sun Qifang,Yingbin Hao,Yongquan Liu,Meng Cui,Zhang Gaowei,Yu Wenjie,Liping Luo
Citrus Huanglongbing, one of the most devastating citrus diseases, is caused by Candidatus Liberibacter asiaticus (CLas). Polyamines are aliphatic nitrogen-containing compounds that play important roles in disease resistance. However, the role of polyamine metabolism in the tolerance of citrus to infection with CLas have not been extensively studied. We used HPLC and UPLC-Q/TOF-MS to detect the contents of nine polyamine metabolism-related compounds (PMRCs) in six citrus cultivars with varying levels of tolerance to CLas. Moreover, we systematically detected the changes of PMRC and H2O2 contents, and compared the gene expression levels and activities of enzymes involved in the polyamine metabolic pathway among healthy, asymptomatic, and symptomatic leaves of Newhall navel oranges infected with CLas. The tolerant and moderately tolerant varieties showed higher PMRC levels than those of susceptible varieties. Compared with the healthy group, the symptomatic group showed significantly increased contents of arginine, ornithine, γ-aminobutyric acid, and putrescine by approximately 180, 19, 1.5, and 0.2 times, respectively, and up-regulated expression of biosynthetic genes. Arginase and ornithine decarboxylase enzyme activities were the highest in the symptomatic group, while arginine decarboxylase and agmatine deiminase enzyme activities were the highest in the asymptomatic group. The two polyamine biosynthetic pathways showed different trends with the increase of the titer of CLas, indicating that polyamines were mainly synthesized through the arginine decarboxylase pathway in the asymptomatic leaves, and were synthesized via the ornithine decarboxylase pathway in symptomatic leaves. These findings provide new insight into the changes of polyamine metabolism in citrus infected with CLas.
研究领域:
植物学
·
分子生物学
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DOI
PubMed
高影响因子
PLANT CELL REPORTS
·
2025
·Vol. 44
·期 2
·1-15
·
IF 4.5
Li Xue,Zhou Yue,Chen Hang,Guo Zetian,Zhang Jinlian,Chen Wenli
Key message The three SDEs of C Las were expressed in citrus leaves by AuNPs-PEI mediated transient expression system, and promoted the proliferation of C Las and inhibited citrus immunity. Huanglongbing (HLB) is the most severe bacterial disease of citrus caused by Candidatus Liberibacter asiaticus ( C Las). C Las suppress host immune responses and promote infection by sec-dependent effectors (SDEs), thus insight into HLB pathogenesis is urgently needed to develop effective management strategies. In this study, we focused on the roles of SDE4310 , SDE4435 and SDE4955 in citrus. We found that the expression of SDE4310 , SDE4435 and SDE4955 to increase with increasing citrus immune genes CsPR1 , CsPR2 , CsPR5 , CsNPR1 , CsRBOHD , CsMAP3K and CsBIK1 , suggesting that the level of citrus immunity could be judged by the expression of SDE. To further explore the relationship between these three SDEs and citrus immunity, we established a transient expression system in citrus leaves, using gold nanoparticle-polyethyleneimine (AuNPs-PEI) to deliver recombinant plasmid containing SDE4310 , SDE4435 or SDE4955 respectively into citrus leaves. Results showed that SDE4310 , SDE4435 and SDE4955 were successfully expressed in citrus leaves using this transient expression system, and found that SDE4310 , SDE4435 and SDE4955 could promote the C Las proliferation by decreasing the immune gene expression of the citrus. Additionally, we used AuNPs-PEI to deliver siRNA 4310 to citrus cells, significantly reducing the expression of SDE4310 within 3 days. Although the suppression of SDE4310 expression did not inhibit the C Las proliferation, it increased the expression level of CsPR1 , CsNPR1 and CsBIK1 . This is also the first time that AuNPs-PEI has been found to be able to deliver exogenous plasmids into citrus cells and express the target protein, providing a new method for future studies on citrus HLB.
研究领域:
植物病理学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Horticultural Plant Journal
·
2026
·
IF 7.1
Yongquan Liu,Lu Jiang,Ahui Xue,Qifang Sun,Yingbin Hao,Meng Cui,Liping Luo
Citrus huanglongbing arises primarily due to Candidatus Liberibacter asiaticus ( C Las), transmitted by Asian citrus psyllids (ACP). To investigate the defense mechanisms of citrus against ACP feeding mediated by C Las, we investigated the metabolomic and transcriptomic variations in navel orange subjected to feeding by either ACP C Las-infected (ACP+) or -noninfected (ACP−) Asian citrus psyllids. This resulted in the establishment of the following groups: ACP+24 h, ACP+72 h, ACP−24 h, ACP−72 h, and control groups, respectively. The results indicated that both C Las and ACP influenced the release of volatile organic compounds, flavonoid biosynthesis, salicylic acid (SA)-jasmonic acid (JA) signaling pathway, and photosynthesis in citrus. Specifically, the levels of 3-carene, linalool, methyl salicylate, and citronellol were increased at ACP+24 h, exhibiting attraction effect on ACP−, while acting as a repellent to ACP+, which may promote the spread of C Las. Genes CsDXS3, CsADH, and CsADH3 probably contributed to in geraniol degradation. SA signaling was activated, upregulating the genes of nonexpressor of pathogenesis-related and pathogenesis-related proteins in systemic acquired resistance. However, downregulation of CsAOS , CsAOC , CsJAR1 , and CsJAZ corresponded with decreasing trend in compounds related to α-linolenic acid metabolic, indicating the SA-JA antagonism. These findings offer novel insights into C Las involvement in citrus initial responses to ACP feeding, contributing to understanding of citrus- C Las-ACP interactions.
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产品关联
DOI
高影响因子
Antibiotics-Basel
·
2020
·Vol. 9
·期 12
·874
·
IF 3.893
Chuanyu Yang,Hanqing Hu,Yihong Wu,Xiongjie Lin,Goucheng Fan,Yongping Duan,Charles Powell,Veronica Ancona,Muqing Zhang
Citrus huanglongbing (HLB) is a devastating disease for the citrus industry. The previous studies demonstrated that oxytetracycline and penicillin are effective antibiotics againstCandidatusLiberibacter asiaticus (CLas). However, sinceCLas is uncultured, the mechanisms of action of antibiotics againstCLas are still unclear. It was recently reported that the endophytic microbial communities are associated with the progression of citrus HLB after oxytetracycline and penicillin treatment. Therefore, we hypothesize that penicillin has greater antibacterial activity againstCLas than oxytetracycline, which may be associated with the alteration of the structure and function of endophytic microbial communities in HLB-affected citrus in response to these antibiotics. To test this hypothesis, the microbiome of HLB-affected citrus leaves treated with these two antibiotics was analyzed using a metagenomic method. Our results indicate that the microbial structure and function in HLB-affected citrus were altered by these two antibiotics. The relative abundance of beneficial bacterial species, includingStreptomyces avermitilisandBradyrhizobium,was higher in penicillin-treated plants compared to those treated with oxytetracycline, and the relative abundance of the bacterial species (such asPropionibacterium acnesandSynechocystissp PCC 6803) associated withCLas survival was lower for penicillin-treated plants compared to oxytetracycline-treated plants. These results indicate that penicillin has greater antibacterial activity againstCLas. Based on the metagenomic analysis, this study elucidated the mechanism for the observed increase in antibacterial activity of penicillin againstCLas. The data presented here are not only invaluable for developing eco-friendly and effective biocontrol strategies to combat citrus HLB, but also provide a method for revealing mechanism of antimicrobial against uncultured bacteria in host.Keywords:citrus Huanglongbing;endophytic microbiome;oxytetracyline;penicillin;mode of action
研究领域:
植物病理学
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微生物学
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产品关联
DOI
PubMed
高影响因子
Foods
·
2024
·Vol. 13
·期 6
·827
·
IF 4.7
Jiayin Liang,Yuqing Xi,Jiaming Li,Shugui Xu,Yongqin Zheng,Meirong Xu,Zheng Zheng,Xiaoling Deng
Citri ReticulataePericarpium, especially the pericarp ofCitrus reticulataBlanco cv. Chachiensis (PCRC), is an important edible and medicinal ingredient for health and pharmacological properties. Citrus Huanglongbing, a devastating disease that currently threatens the citrus industry worldwide, is caused by a phloem-limited alpha-proteobacterium, “CandidatusLiberibacter asiaticus” (CLas). The industry of cultivar Chachiensis has been suffering from HLB. Although HLB affected the quality of citrus fruit, whether the quality of PCRC was affected by HLB remains unclear. In this study, we compared the metabolite profiles between HLB-affected and healthy PCRC from three sources: fresh, 6-month-old, and 9-year-old PCRC, through the untargeted LC–MS method. Compared to healthy controls, various types of bioactive compounds, mainly flavonoids, terpenoids, alkaloids, coumarins, polysaccharides, and phenolic acids, accumulated in HLB-affected PCRC, especially in the HLB-affected 9-year PCRC. In particular, isorhamnetin, isoliquiritigenin, luteolin 7-O-beta-D-glucoside, limonin, geniposide, pyrimidodiazepine, scoparone, chitobiose, m-coumaric acid, malonate, and pantothenic acid, which contributed to the pharmacological activity and health care effects of PCRC, were highly accumulated in HLB-affected 9-year-old PCRC compared to the healthy control. Multibioassay analyses revealed that HLB-affected 9-year-old PCRC had a higher content of total flavonoids and total polyphenols and exhibited similar antioxidant capacity as compared to healthy controls. The results of this study provided detailed information on the quality of HLB-affected PCRC.
研究领域:
植物科学
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药理学
·
农业科学
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代谢组学
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DOI
PubMed
高影响因子
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