Rice aquaporin PIP1;3 and harpin Hpa1 of bacterial blight pathogen cooperate in a type III effector translocation

Li, Ping; Zhang, Liyuan; Mo, Xuyan; Ji, Hongtao; Bian, H W; Hu, Yiqun; Majid, Taha; Long, Juying; Pang, Hao; Yuan, Tao; Ma, Jinbiao; Dong, Hansong

doi:10.1093/jxb/erz130

Cited by 48 publications

(70 citation statements)

References 71 publications

(154 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To date, most research studies on harpins have focused on their biological activities [13,21,22]. For example, many studies have characterized harpin functional domains [3,12,23,24] and the roles of harpins in non-host plants [25][26][27]. Only a few research studies have assessed the thermal stability of harpins.…”

Section: Introductionmentioning

confidence: 99%

HpaXpm, a novel harpin of Xanthomonas phaseoli pv. manihotis, acts as an elicitor with high thermal stability, reduces disease, and promotes plant growth

et al. 2020

View full text Add to dashboard Cite

Background: Harpins are proteins secreted by the type III secretion system of Gram-negative bacteria during pathogen-plant interactions that can act as elicitors, stimulating defense and plant growth in many types of nonhost plants. Harpin-treated plants have higher resistance, quality and yields and, therefore, harpin proteins may potentially have many valuable agricultural applications. Harpins are characterized by high thermal stability at 100°C. However, it is unknown whether harpins are still active at temperatures above 100°C or whether different temperatures affect the activity of the harpin protein in different ways. The mechanism responsible for the heat stability of harpins is also unknown. Results: We identified a novel harpin, HpaXpm, from the cassava blight bacteria Xanthomonas phaseoli pv. manihotis HNHK. The predicted secondary structure and 3-D structure indicated that the HpaXpm protein has two β-strand domains and two major α-helical domains located at the N-and C-terminal regions, respectively. A phylogenetic tree generated using the maximum likelihood method grouped HpaXpm in clade I of the Hpa1 group along with harpins produced by other Xanthomonas spp. (i.e., HpaG-Xag, HpaG-Xcm, Hpa1-Xac, and Hpa1Xm). Phenotypic assays showed that HpaXpm induced the hypersensitive response (HR), defense responses, and growth promotion in non-host plants more effectively than Hp1Xoo (X. oryzae pv. oryzae). Quantitative realtime PCR analysis indicated that HpaXpm proteins subjected to heat treatments at 100°C, 150°C, or 200°C were still able to stimulate the expression of function-related genes (i.e., the HR marker genes Hin1 and Hsr203J, the defense-related gene NPR1, and the plant growth enhancement-related gene NtEXP6); however, the ability of heattreated HpaXpm to induce HR was different at different temperatures. Conclusions: These findings add a new member to the harpin family. HpaXpm is heat-stable up to 200°C and is able to stimulate powerful beneficial biological functions that could potentially be more valuable for agricultural applications than those stimulated by Hpa1Xoo. We hypothesize that the extreme heat resistance of HpaXpm is because the structure of harpin is very stable and, therefore, the HpaXpm structure is less affected by temperature.

show abstract

Section: Introductionmentioning

confidence: 99%

HpaXpm, a novel harpin of Xanthomonas phaseoli pv. manihotis, acts as an elicitor with high thermal stability, reduces disease, and promotes plant growth

et al. 2020

View full text Add to dashboard Cite

show abstract

“…We have identified Hpa2, HrpF, and XopN as concomitant translocators of the Xoo TALE PthXo1, which was well studied with respect to its function in determining virulence of the standard Xoo strain PXO99 A on the susceptible variety Nipponbare (Yang et al, 2006;Wang et al, 2018;Bian et al, 2019;Li et al, 2019;Zhang et al, 2019b). Evidence that demonstrates the translocator role has been shown as quantitative changes of PthXo1 translocation in Nipponbare plants inoculated with the WT and genetically modified POX99 A strains in the presence and absence of Hpa2, HrpF, and XopN, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…In the Cya reporter assay using rice leaves inoculated by the leaf-center-infiltrating method as did usually (Kvitko et al, 2007;Chakravarthy et al, 2017;Li et al, 2019), Hpa2, HrpF, and XopN were found to partake in PthXo1 translocation from PXO99 A -bacterial cells into the cytosol of Nipponbare cells. To initiate the assay, two elder leaves of 14-day-old Nipponbare seedlings were infiltrated with every bacterial suspension of pertinent Xoo strains.…”

Section: Hpa2 Hrpf and Xopn Are Concomitant Translocators Of Pthxo1mentioning

confidence: 92%

“…We looked for functional connections of Hpa2, HrpF, and XopN, which differentially contribute to PXO99 A virulence on the rice variety Nipponbare (Figures 1, 2), with the bacterial TALE PthXo1, which determines the bacterial virulence (Yang et al, 2006) following secretion by the bacterial T3 pathway and translocation into Nipponbare cells (Li et al, 2019). Thus, we analyzed the effects of Hpa2, HrpF, and XopN on PthXo1 secretion and translocation.…”

Section: None Of Hpa2 Hrpf and Xopn Affects Pthxo1 Secretionmentioning

confidence: 99%

See 1 more Smart Citation

Three Proteins (Hpa2, HrpF and XopN) Are Concomitant Type III Translocators in Bacterial Blight Pathogen of Rice

Zhang

Liu

et al. 2020

Front. Microbiol.

Self Cite

View full text Add to dashboard Cite

Type III (T3) proteic effectors occupy most of the virulence determinants in eukaryote-pathogenic Gram-negative bacteria. During infection, bacteria may deploy a nanomachinery called translocon to deliver T3 effectors into host cells, wherein the effectors fulfill their pathological functions. T3 translocon is hypothetically assembled by bacterial translocators, which have been identified as one hydrophilic and two hydrophobic proteins in animal-pathogenic bacteria but remain unclear in plant pathogens. Now we characterize Hpa2, HrpF, and XopN proteins as concomitant T3 translocators in rice bacterial blight pathogen by analyzing pathological consequences of single, double, and triple gene knockout or genetic complementation. Based on these genetic analyses, Hpa2, HrpF, and XopN accordingly contribute to 46.9, 60.3, and 69.8% proportions of bacterial virulence on a susceptible rice variety. Virulence performances of Hpa2, HrpF, and XopN were attributed to their functions in essentially mediating from-bacteria-into-rice-cell translocation of PthXo1, the bacterial T3 effector characteristic of transcription factors targeting plant genes. On average, 61, 62, and 71% of PthXo1 translocation are provided correspondingly by Hpa2, HrpF, and XopN, while they cooperate to support PthXo1 translocation at a greater-than-95% extent. As a result, rice disease-susceptibility gene SWEET11, which is the regulatory target of PthXo1, is activated to confer bacterial virulence and induce the leaf blight disease in rice. Furthermore, the three translocators also undergo translocation, but only XopN is highly translocated to suppress rice defense responses, suggesting that different components of a T3 translocon deploy distinct virulence mechanisms in addition to the common function in mediating bacterial effector translocation.

show abstract

“…Pathogens deliver various effectors into plant host cells when pathogens attack plants. These effectors assist pathogen proliferation and suppress plant defense responses [ 95 , 96 , 97 , 98 , 99 , 100 , 101 ]. Two Pseudomonas effectors, HopR1 and HopBB1, has been suggested to be involved in psbD transcription by targeting PTF1 (PLASTID TRANSCRIPTION FACTOR 1), a transcription factor for psbD BLRP transcription [ 102 , 103 ].…”

Section: Chloroplast Gene Expression and Environmental Stressmentioning

confidence: 99%

The Role of Chloroplast Gene Expression in Plant Responses to Environmental Stress

Zhang

et al. 2020

IJMS

View full text Add to dashboard Cite

Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent. Here, we discuss the emerging roles of the distinct chloroplast gene expression processes in plant responses to environmental stresses. For example, the transcription and translation of psbA play an important role in high-light stress responses. A better understanding of the connection between chloroplast gene expression and environmental stress responses is crucial for breeding stress-tolerant crops better able to cope with the rapidly changing environment.

show abstract

Rice aquaporin PIP1;3 and harpin Hpa1 of bacterial blight pathogen cooperate in a type III effector translocation

Cited by 48 publications

References 71 publications

HpaXpm, a novel harpin of Xanthomonas phaseoli pv. manihotis, acts as an elicitor with high thermal stability, reduces disease, and promotes plant growth

HpaXpm, a novel harpin of Xanthomonas phaseoli pv. manihotis, acts as an elicitor with high thermal stability, reduces disease, and promotes plant growth

Three Proteins (Hpa2, HrpF and XopN) Are Concomitant Type III Translocators in Bacterial Blight Pathogen of Rice

The Role of Chloroplast Gene Expression in Plant Responses to Environmental Stress

Contact Info

Product

Resources

About