1
|
Iglesias R, Citores L, Gay CC, Ferreras JM. Antifungal Activity of Ribosome-Inactivating Proteins. Toxins (Basel) 2024; 16:192. [PMID: 38668617 PMCID: PMC11054410 DOI: 10.3390/toxins16040192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/04/2024] [Accepted: 04/12/2024] [Indexed: 04/29/2024] Open
Abstract
The control of crop diseases caused by fungi remains a major problem and there is a need to find effective fungicides that are environmentally friendly. Plants are an excellent source for this purpose because they have developed defense mechanisms to cope with fungal infections. Among the plant proteins that play a role in defense are ribosome-inactivating proteins (RIPs), enzymes obtained mainly from angiosperms that, in addition to inactivating ribosomes, have been studied as antiviral, fungicidal, and insecticidal proteins. In this review, we summarize and discuss the potential use of RIPs (and other proteins with similar activity) as antifungal agents, with special emphasis on RIP/fungus specificity, possible mechanisms of antifungal action, and the use of RIP genes to obtain fungus-resistant transgenic plants. It also highlights the fact that these proteins also have antiviral and insecticidal activity, which makes them very versatile tools for crop protection.
Collapse
Affiliation(s)
- Rosario Iglesias
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain; (R.I.); (L.C.)
| | - Lucía Citores
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain; (R.I.); (L.C.)
| | - Claudia C. Gay
- Laboratory of Protein Research, Institute of Basic and Applied Chemistry of Northeast Argentina (UNNE-CONICET), Faculty of Exact and Natural Sciences and Surveying, Av. Libertad 5470, Corrientes 3400, Argentina;
| | - José M. Ferreras
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain; (R.I.); (L.C.)
| |
Collapse
|
2
|
Benaissa A. Rhizosphere: Role of bacteria to manage plant diseases and sustainable agriculture-A review. J Basic Microbiol 2024; 64:e2300361. [PMID: 37800617 DOI: 10.1002/jobm.202300361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 09/05/2023] [Accepted: 09/17/2023] [Indexed: 10/07/2023]
Abstract
General plant diseases as well as soil-borne pathogens severely reduce agricultural yield. The rhizosphere (the region of the soil that includes and surrounds the roots) is an important niche for microbial diversity in particular phytobeneficial bacteria including plant growth-promoting rhizobacteria (PGPR) which have been used for a very long time to combat plant diseases. Pathogen control and crop productivity can both be improved through the use of PGPR several mechanisms, including iron-based nutrition, antibiotics, volatile substances, enzymes, biofilm, allelochemicals, and so on. Their modes of action and molecular mechanisms have improved our comprehension of how they are used to control crop disease. Therefore, there is a lot of literal information available regarding PGPR, but this review stands out since it starts with the fundamentals: the concept of the rhizosphere and the colonization process of the latter, particularly because it covers the most mechanisms. A broad figure is used to present the study's findings. The advantages of using PGPR as bioinoculants in sustainable agriculture are also mentioned.
Collapse
Affiliation(s)
- Asmaa Benaissa
- Laboratory of Biology and Physiology of Organisms, Faculty of Biological Sciences, University of Sciences and Technology of Houari Boumediene-El-Alia Bab Ezzouar Algiers, Algeria
- Department of Biology, University of Amine Elokkal ElHadj Moussa Eg. Akhamoukh, Sersouf, Tamanrasset, Algeria
| |
Collapse
|
3
|
Citores L, Iglesias R, Ferreras JM. Antiviral Activity of Ribosome-Inactivating Proteins. Toxins (Basel) 2021; 13:80. [PMID: 33499086 PMCID: PMC7912582 DOI: 10.3390/toxins13020080] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022] Open
Abstract
Ribosome-inactivating proteins (RIPs) are rRNA N-glycosylases from plants (EC 3.2.2.22) that inactivate ribosomes thus inhibiting protein synthesis. The antiviral properties of RIPs have been investigated for more than four decades. However, interest in these proteins is rising due to the emergence of infectious diseases caused by new viruses and the difficulty in treating viral infections. On the other hand, there is a growing need to control crop diseases without resorting to the use of phytosanitary products which are very harmful to the environment and in this respect, RIPs have been shown as a promising tool that can be used to obtain transgenic plants resistant to viruses. The way in which RIPs exert their antiviral effect continues to be the subject of intense research and several mechanisms of action have been proposed. The purpose of this review is to examine the research studies that deal with this matter, placing special emphasis on the most recent findings.
Collapse
Affiliation(s)
| | | | - José M. Ferreras
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain; (L.C.); (R.I.)
| |
Collapse
|
4
|
Li YX, Zhang W, Dong HX, Liu ZY, Ma J, Zhang XY. Salicylic acid in Populus tomentosa is a remote signalling molecule induced by Botryosphaeria dothidea infection. Sci Rep 2018; 8:14059. [PMID: 30232461 PMCID: PMC6145909 DOI: 10.1038/s41598-018-32204-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 05/02/2018] [Indexed: 12/21/2022] Open
Abstract
The salicylic acid (SA) plays a critical role during the establishment of systemic acquired resistance (SAR) in uninfected plant tissues after localised exposure to a pathogen. Here, we studied SA in Populus tomentosa infected by the plant pathogen Botryosphaeria dothidea. The accumulation of SA and methyl salicylate (MeSA) occurred in chronological order in P. tomentosa. The SA and MeSA contents were greater at infected than uninfected sites. Additionally, a gene expression analysis indicated that SA might be accumulated by phenylalanine ammonialyase (PAL) and converted to MeSA by SA carboxyl methyltransferase (SAMT), while MeSA might convert to SA by SA-binding protein 2 (SABP2). The expressions of SAMT at infected sites and SABP2 at uninfected sites, respectively, were significantly up-regulated. Thus, SA might be converted to MeSA at infected sites and transported as a signalling molecule to uninfected sites, where it is converted to SA for SAR. Moreover, the expressions of pathogenesis-related genes PR-1, PR-2 and PR-5 in P. tomentosa were up-regulated by the B. dothidea infection. Our study determined that variations in SA and MeSA contents occur at infected and uninfected sites in poplar after pathogen infection and contributed to the remote signals for poplar SAR.
Collapse
Affiliation(s)
- Yong-Xia Li
- Lab. of Forest Pathogen Integrated Biology, Research Institute of Forestry New Technology, Chinese Academy of Forestry, Beijing, 100091, China.,Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Wei Zhang
- Lab. of Forest Pathogen Integrated Biology, Research Institute of Forestry New Technology, Chinese Academy of Forestry, Beijing, 100091, China.,Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Hui-Xia Dong
- Lab. of Forest Pathogen Integrated Biology, Research Institute of Forestry New Technology, Chinese Academy of Forestry, Beijing, 100091, China.,College of Life Science, Henan Normal University, Xinxiang, 453007, China
| | - Zhen-Yu Liu
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.,College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - Jian Ma
- Lab. of Forest Pathogen Integrated Biology, Research Institute of Forestry New Technology, Chinese Academy of Forestry, Beijing, 100091, China.,Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Xing-Yao Zhang
- Lab. of Forest Pathogen Integrated Biology, Research Institute of Forestry New Technology, Chinese Academy of Forestry, Beijing, 100091, China. .,Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
| |
Collapse
|
5
|
Tsutsui H, Notaguchi M. The Use of Grafting to Study Systemic Signaling in Plants. PLANT & CELL PHYSIOLOGY 2017; 58:1291-1301. [PMID: 28961994 DOI: 10.1093/pcp/pcx098] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/10/2017] [Indexed: 05/03/2023]
Abstract
Grafting has long been an important technique in agriculture. Nowadays, grafting is a widely used technique also to study systemic long-distance signaling in plants. Plants respond to their surrounding environment, and at that time many aspects of their physiology are regulated systemically; these start from local input signals and are followed by the transmission of information to the rest of the plant. For example, soil nutrient conditions, light/photoperiod, and biotic and abiotic stresses affect plants heterogeneously, and plants perceive such information in specific plant tissues or organs. Such environmental cues are crucial determinants of plant growth and development, and plants drastically change their morphology and physiology to adapt to various events in their life. Hitherto, intensive studies have been conducted to understand systemic signaling in plants, and grafting techniques have permitted advances in this field. The breakthrough technique of micrografting in Arabidopsis thaliana was established in 2002 and led to the development of molecular genetic tools in this field. Thereafter, various phenomena of systemic signaling have been identified at the molecular level, including nutrient fixation, flowering, circadian clock and defense against pathogens. The significance of grafting is that it can clarify the transmission of the stimulus and molecules. At present, many micro- and macromolecules have been identified as mobile signals, which are transported through plant vascular tissues to co-ordinate their physiology and development. In this review, we introduce the various grafting techniques that have been developed, we report on the recent advances in the field of plant systemic signaling where grafting techniques have been applied and provide insights for the future.
Collapse
Affiliation(s)
- Hiroki Tsutsui
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Michitaka Notaguchi
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
- Japan Science and Technology Agency, PRESTO, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| |
Collapse
|
6
|
Albacete A, Martínez-Andújar C, Martínez-Pérez A, Thompson AJ, Dodd IC, Pérez-Alfocea F. Unravelling rootstock×scion interactions to improve food security. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2211-26. [PMID: 25754404 PMCID: PMC4986720 DOI: 10.1093/jxb/erv027] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 12/12/2014] [Accepted: 01/08/2015] [Indexed: 05/19/2023]
Abstract
While much recent science has focused on understanding and exploiting root traits as new opportunities for crop improvement, the use of rootstocks has enhanced productivity of woody perennial crops for centuries. Grafting of vegetable crops has developed very quickly in the last 50 years, mainly to induce shoot vigour and to overcome soil-borne diseases in solanaceous and cucurbitaceous crops. In most cases, such progress has largely been due to empirical interactions between farmers, gardeners, and botanists, with limited insights into the underlying physiological mechanisms. Only during the last 20 years has science realized the potential of this old activity and studied the physiological and molecular mechanisms involved in rootstock×scion interactions, thereby not only explaining old phenomena but also developing new tools for crop improvement. Rootstocks can contribute to food security by: (i) increasing the yield potential of elite varieties; (ii) closing the yield gap under suboptimal growing conditions; (iii) decreasing the amount of chemical (pesticides and fertilizers) contaminants in the soil; (iv) increasing the efficiency of use of natural (water and soil) resources; (v) generating new useful genotypic variability (via epigenetics); and (vi) creating new products with improved quality. The potential of grafting is as broad as the genetic variability able to cross a potential incompatibility barrier between the rootstock and the scion. Therefore, understanding the mechanisms underlying the phenotypic variability resulting from rootstock×scion×environment interactions will certainly contribute to developing and exploiting rootstocks for food security.
Collapse
Affiliation(s)
- Alfonso Albacete
- Departamento de Nutrición Vegetal, CEBAS-CSIC, Campus Universitario de Espinardo, 25, E-30100 Murcia, Spain
| | - Cristina Martínez-Andújar
- Departamento de Nutrición Vegetal, CEBAS-CSIC, Campus Universitario de Espinardo, 25, E-30100 Murcia, Spain
| | - Ascensión Martínez-Pérez
- Departamento de Nutrición Vegetal, CEBAS-CSIC, Campus Universitario de Espinardo, 25, E-30100 Murcia, Spain
| | - Andrew J Thompson
- School of Energy, Environment and Agrifood, Cranfield University, Bedfordshire MK43 0AL, UK
| | - Ian C Dodd
- Lancaster Environment Centre, University of Lancaster, Lancaster LA1 4YQ, UK
| | - Francisco Pérez-Alfocea
- Departamento de Nutrición Vegetal, CEBAS-CSIC, Campus Universitario de Espinardo, 25, E-30100 Murcia, Spain
| |
Collapse
|
7
|
Di R, Tumer NE. Pokeweed antiviral protein: its cytotoxicity mechanism and applications in plant disease resistance. Toxins (Basel) 2015; 7:755-72. [PMID: 25756953 PMCID: PMC4379523 DOI: 10.3390/toxins7030755] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 02/11/2015] [Accepted: 03/02/2015] [Indexed: 11/16/2022] Open
Abstract
Pokeweed antiviral protein (PAP) is a 29 kDa type I ribosome inactivating protein (RIP) found in pokeweed plants. Pokeweed produces different forms of PAP. This review focuses on the spring form of PAP isolated from Phytolacca americana leaves. PAP exerts its cytotoxicity by removing a specific adenine from the α-sarcin/ricin loop of the large ribosomal RNA. Besides depurination of the rRNA, PAP has additional activities that contribute to its cytotoxicity. The mechanism of PAP cytotoxicity is summarized based on evidence from the analysis of transgenic plants and the yeast model system. PAP was initially found to be anti-viral when it was co-inoculated with plant viruses onto plants. Transgenic plants expressing PAP and non-toxic PAP mutants have displayed broad-spectrum resistance to both viral and fungal infection. The mechanism of PAP-induced disease resistance in transgenic plants is summarized.
Collapse
Affiliation(s)
- Rong Di
- Department of Plant Biology and Pathology, Rutgers, the State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, USA.
| | - Nilgun E Tumer
- Department of Plant Biology and Pathology, Rutgers, the State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, USA.
| |
Collapse
|
8
|
Haroldsen VM, Szczerba MW, Aktas H, Lopez-Baltazar J, Odias MJ, Chi-Ham CL, Labavitch JM, Bennett AB, Powell ALT. Mobility of Transgenic Nucleic Acids and Proteins within Grafted Rootstocks for Agricultural Improvement. FRONTIERS IN PLANT SCIENCE 2012; 3:39. [PMID: 22645583 PMCID: PMC3355758 DOI: 10.3389/fpls.2012.00039] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 02/17/2012] [Indexed: 05/03/2023]
Abstract
Grafting has been used in agriculture for over 2000 years. Disease resistance and environmental tolerance are highly beneficial traits that can be provided through use of grafting, although the mechanisms, in particular for resistance, have frequently been unknown. As information emerges that describes plant disease resistance mechanisms, the proteins, and nucleic acids that play a critical role in disease management can be expressed in genetically engineered (GE) plant lines. Utilizing transgrafting, the combination of a GE rootstock with a wild-type (WT) scion, or the reverse, has the potential to provide pest and pathogen resistance, impart biotic and abiotic stress tolerance, or increase plant vigor and productivity. Of central importance to these potential benefits is the question of to what extent nucleic acids and proteins are transmitted across a graft junction and whether the movement of these molecules will affect the efficacy of the transgrafting approach. Using a variety of specific examples, this review will report on the movement of organellar DNA, RNAs, and proteins across graft unions. Attention will be specifically drawn to the use of small RNAs and gene silencing within transgrafted plants, with a particular focus on pathogen resistance. The use of GE rootstocks or scions has the potential to extend the horticultural utility of grafting by combining this ancient technique with the molecular strategies of the modern era.
Collapse
Affiliation(s)
| | - Mark W. Szczerba
- Department of Plant Sciences, University of CaliforniaDavis, CA, USA
| | - Hakan Aktas
- Department of Plant Sciences, University of CaliforniaDavis, CA, USA
- Department of Horticulture, Faculty of Agriculture, University of Suleyman DemirelIsparta, Turkey
| | - Javier Lopez-Baltazar
- Department of Plant Sciences, University of CaliforniaDavis, CA, USA
- Instituto Tecnologico del Valle de OaxacaOaxaca, Mexico
| | - Mar Joseph Odias
- Department of Plant Sciences, University of CaliforniaDavis, CA, USA
| | | | - John M. Labavitch
- Department of Plant Sciences, University of CaliforniaDavis, CA, USA
| | - Alan B. Bennett
- Department of Plant Sciences, University of CaliforniaDavis, CA, USA
| | - Ann L. T. Powell
- Department of Plant Sciences, University of CaliforniaDavis, CA, USA
| |
Collapse
|
9
|
Marshall RS, D'Avila F, Di Cola A, Traini R, Spanò L, Fabbrini MS, Ceriotti A. Signal peptide-regulated toxicity of a plant ribosome-inactivating protein during cell stress. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 65:218-29. [PMID: 21223387 DOI: 10.1111/j.1365-313x.2010.04413.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The fate of the type I ribosome-inactivating protein (RIP) saporin when initially targeted to the endoplasmic reticulum (ER) in tobacco protoplasts has been examined. We find that saporin expression causes a marked decrease in protein synthesis, indicating that a fraction of the toxin reaches the cytosol and inactivates tobacco ribosomes. We determined that saporin is largely secreted but some is retained intracellularly, most likely in a vacuolar compartment, thus behaving very differently from the prototype RIP ricin A chain. We also find that the signal peptide can interfere with the catalytic activity of saporin when the protein fails to be targeted to the ER membrane, and that saporin toxicity undergoes signal sequence-specific regulation when the host cell is subjected to ER stress. Replacement of the saporin signal peptide with that of the ER chaperone BiP reduces saporin toxicity and makes it independent of cell stress. We propose that this stress-induced toxicity may have a role in pathogen defence.
Collapse
Affiliation(s)
- Richard S Marshall
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Via Bassini 15, 20133 Milano, Italy
| | | | | | | | | | | | | |
Collapse
|
10
|
Takahashi H, Matsumura H, Kawai-Yamada M, Uchimiya H. The cell death factor, cell wall elicitor of rice blast fungus (Magnaporthe grisea) causes metabolic alterations including GABA shunt in rice cultured cells. PLANT SIGNALING & BEHAVIOR 2008; 3:945-53. [PMID: 19513197 PMCID: PMC2633740 DOI: 10.4161/psb.6112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Accepted: 04/15/2008] [Indexed: 05/05/2023]
Abstract
An elicitor derived from the cell wall of rice blast fungus (Magnaporthe grisea) causes cell death in suspension cultured cells of rice (Oryza sativa L.). To elucidate the role of M. grisea elicitor on metabolic pathway of rice cells, we performed metabolite profiling using capillary electrophoresis-mass spectrometry (CE/MS). Treatment with M. grisea elicitor increased the amounts of antioxidants and free amino acids and decreased the amount of metabolites in the tricarboxylic acid (TCA) cycle. Lower ATP concentration caused aberrant energy charge, concurrently with reduced amount of NAD(P)H in elicitor treated cells. Among free amino acids detected in this study, the level of gamma-aminobutyric acid (GABA) increased. GABA is metabolized through a bypass pathway of the TCA cycle called GABA shunt, which is composed of glutamate decarboxylase (GAD), GABA transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH). While M. grisea elicitor negligibly affected GAD and SSADH, GABA-T activity significantly decreased. The decrease in GABA-T activity was recovered by NADPH oxidase inhibitor, which prevents cell death induced by M. grisea elicitor. Thus, GABA accumulation observed in rice cells under elicitor stress is partly associated with GABA-T activity.
Collapse
Affiliation(s)
| | - Hideo Matsumura
- Iwate Biotechnology Research Center; Narita; Kitakami, Iwate Japan
| | - Maki Kawai-Yamada
- Institute of Molecular and Cellular Biosciences; The University of Tokyo; Yayoi; Bunkyo-ku, Tokyo Japan
| | - Hirofumi Uchimiya
- Iwate Biotechnology Research Center; Narita; Kitakami, Iwate Japan
- Institute of Molecular and Cellular Biosciences; The University of Tokyo; Yayoi; Bunkyo-ku, Tokyo Japan
| |
Collapse
|
11
|
Zhou WW, Zhang LX, Zhang B, Wang F, Liang ZH, Niu TG. Isolation and characterization of ZH14 with antiviral activity againstTobacco mosaic virus. Can J Microbiol 2008; 54:441-9. [DOI: 10.1139/w08-026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A large number of bacteria were isolated from plant samples and screened for antiviral activity against the Tobacco mosaic virus (TMV). The bacterium ZH14, which was isolated from Chinese Anxi oolong tea, secreted the antiviral substances, having 94.2% virus inhibition when the bacterial culture filtrate and TMV extract were mixed at a ratio of 1:1. The ZH14 strain is a gram-positive, spore-forming rod and has the ability to degrade ribonucleic acid. Based on its effectiveness on virus inhibition, ZH14 was selected for characterization and was identified as a strain of the Bacillus cereus group based on phenotypic tests and comparative analysis of its 16S rDNA sequence. At the same time, we determined the antiviral product of ZH14 as an extracellular protein with high molecular mass, having an optimum temperature of 15–60 °C and an optimum pH of 6–10. Hence, the ZH14 strain and its culture filtrate have potential application in controlling plant diseases caused by TMV.
Collapse
Affiliation(s)
- Wen-Wen Zhou
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083 Beijing, China
| | - Li-Xiang Zhang
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083 Beijing, China
| | - Bin Zhang
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083 Beijing, China
| | - Fei Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083 Beijing, China
| | - Zhi-Hong Liang
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083 Beijing, China
| | - Tian-Gui Niu
- College of Food Science and Nutritional Engineering, China Agricultural University, 100083 Beijing, China
| |
Collapse
|
12
|
Roy S, Sadhana P, Begum M, Kumar S, Lodha ML, Kapoor HC. Purification, characterization and cloning of antiviral/ribosome inactivating protein from Amaranthus tricolor leaves. PHYTOCHEMISTRY 2006; 67:1865-73. [PMID: 16859721 DOI: 10.1016/j.phytochem.2006.06.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 06/04/2006] [Accepted: 06/06/2006] [Indexed: 05/09/2023]
Abstract
An antiviral protein (AVP), imparting high level of resistance against sunnhemp rosette virus (SRV) was purified from the dried leaves of Amaranthus tricolor. The purified protein (AAP-27) exhibited approximately 98% inhibition of local lesion formation at a concentration range of approximately 30 microg ml(-1). The protein was found to be highly basic glycoprotein monomer (pI approximately 9.8) of Mr 27 kDa, with neutral sugar content of 4%. The purified protein exhibited N-glycosidase and RNase activities. We have also isolated full-length cDNA clone, encoding this protein designated as A. tricolor antiviral protein-1 (AAP-1). Two primers, one designed on the basis of N-terminal sequence of the purified protein and the other from the conserved active peptides of other AVPs/RIPs were used for PCR amplification of double stranded cDNA, isolated from the leaves of A. tricolor. The amplified fragment was used as a probe for library screening. The isolated full-length cDNA consisted of 1058 nucleotides with an open reading frame encoding a polypeptide of 297 amino acids. The deduced amino acid sequence of AAP-1 has a putative active domain conserved in other AVPs/RIPs and shows varying homology to the RIPs from other plant species.
Collapse
Affiliation(s)
- Sribash Roy
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi 110012, India
| | | | | | | | | | | |
Collapse
|
13
|
Gholizadeh A, Kohnehrouz BB, Santha IM, Lodha ML, Kapoor HC. Cloning and expression of small cDNA fragment encoding strong antiviral peptide from Celosia cristata in Escherichia coli. BIOCHEMISTRY (MOSCOW) 2006; 70:1005-10. [PMID: 16266271 DOI: 10.1007/s10541-005-0216-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A small cDNA fragment containing a ribosome-inactivating site was isolated from the leaf cDNA population of Celosia cristata by polymerase chain reaction (PCR). PCR was conducted linearly using a degenerate primer designed from the partially conserved peptide of ribosome-inactivating/antiviral proteins. Sequence analysis showed that it is 150 bp in length. The cDNA fragment was then cloned in a bacterial expression vector and expressed in Escherichia coli as a ~57 kD fused protein, and its presence was further confirmed by Western blot analysis. The recombinant protein was purified by affinity chromatography. The purified product showed strong antiviral activity towards tobacco mosaic virus on host plant leaves, Nicotiana glutinosa, indicating the presence of a putative antiviral determinant in the isolated cDNA product. It is speculated that antiviral site is at, or is separate but very close to, the ribosome-inactivating site. We nominate this short cDNA fragment reported here as a good candidate to investigate further the location of the antiviral determinants. The isolated cDNA sequence was submitted to EMBL databases under accession number of AJ535714.
Collapse
Affiliation(s)
- A Gholizadeh
- Department of Biology, University of Tabriz, Tabriz, Iran.
| | | | | | | | | |
Collapse
|
14
|
Vandenbussche F, Peumans WJ, Desmyter S, Proost P, Ciani M, Van Damme EJM. The type-1 and type-2 ribosome-inactivating proteins from Iris confer transgenic tobacco plants local but not systemic protection against viruses. PLANTA 2004; 220:211-21. [PMID: 15278456 DOI: 10.1007/s00425-004-1334-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Accepted: 05/29/2004] [Indexed: 05/24/2023]
Abstract
The antiviral activity of the type-2 ribosome-inactivating protein (RIP) IRAb from Iris was analyzed by expressing IRAb in tobacco (Nicotiana tabacum L. cv. Samsun NN) plants and challenging the transgenic plants with tobacco mosaic virus (TMV). Although constitutive expression of IRAb resulted in an aberrant phenotype, the plants were fertile. Transgenic tobacco lines expressing IRAb showed a dose-dependent enhanced resistance against TMV infection but the level of protection was markedly lower than in plants expressing IRIP, the type-1 RIP from Iris that closely resembles the A-chain of IRAb. To verify whether IRIP or IRAb can also confer systemic protection against viruses, transgenic RIP-expressing scions were grafted onto control rootstocks and leaves of the rootstocks challenged with tobacco etch virus (TEV). In spite of the strong local antiviral effect of IRIP and IRAb the RIPs could not provide systemic protection against TEV. Hence our results demonstrate that expression of the type-1 and type-2 RIPs from Iris confers tobacco plants local protection against two unrelated viruses. The antiviral activity of both RIPs was not accompanied by an induction of pathogenesis-related proteins. It is suggested that the observed antiviral activity of both Iris RIPs relies on their RNA N-glycohydrolase activity towards TMV RNA and plant rRNA.
Collapse
Affiliation(s)
- Frank Vandenbussche
- Laboratory for Phytopathology and Plant Protection, Katholieke Universiteit Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium
| | | | | | | | | | | |
Collapse
|
15
|
Affiliation(s)
- Melan Wang
- Department of Biology, York University, 4700 Keele St., Toronto, Ontario, Canada M3J 1P3
| | | |
Collapse
|
16
|
Park SW, Lawrence CB, Linden JC, Vivanco JM. Isolation and characterization of a novel ribosome-inactivating protein from root cultures of pokeweed and its mechanism of secretion from roots. PLANT PHYSIOLOGY 2002. [PMID: 12226497 DOI: 10.1104/pp.000794.of] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Ribosome-inactivating proteins are N-glycosidases that remove a specific adenine from the sarcin/ricin loop of the large rRNA, thus arresting protein synthesis at the translocation step. In the present study, a novel type I ribosome-inactivating protein, termed PAP-H, was purified from Agrobacterium rhizogenes-transformed hairy roots of pokeweed (Phytolacca americana). The protein was purified by anion- and cation-exchange chromatography. PAP-H has a molecular mass of 29.5 kD as detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its isoelectric point was determined to be 7.8. Yeast (Saccharomyces cerevisiae) ribosomes incubated with PAP-H released the 360-nucleotide diagnostic fragment from the 26S rRNA upon aniline treatment, an indication of its ribosome-inactivating activity. Using immunofluorescence microscopy, PAP-H was found to be located in the cell walls of hairy roots and root border cells. PAP-H was determined to be constitutively secreted as part of the root exudates, with its secretion enhanced by a mechanism mediated by ethylene induction. Purified PAP-H did not show in vitro antifungal activity against soil-borne fungi. In contrast, root exudates containing PAP-H as well as additional chitinase, beta-1,3-glucanase, and protease activities did inhibit the growth of soil-borne fungi. We found that PAP-H depurinates fungal ribosomes in vitro and in vivo, suggesting an additive mechanism that enables PAP-H to penetrate fungal cells.
Collapse
Affiliation(s)
- Sang-Wook Park
- Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, Colorado 80523-1173, USA
| | | | | | | |
Collapse
|
17
|
Park SW, Lawrence CB, Linden JC, Vivanco JM. Isolation and characterization of a novel ribosome-inactivating protein from root cultures of pokeweed and its mechanism of secretion from roots. PLANT PHYSIOLOGY 2002; 130:164-78. [PMID: 12226497 PMCID: PMC166550 DOI: 10.1104/pp.000794] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2001] [Revised: 04/26/2002] [Accepted: 05/24/2002] [Indexed: 05/18/2023]
Abstract
Ribosome-inactivating proteins are N-glycosidases that remove a specific adenine from the sarcin/ricin loop of the large rRNA, thus arresting protein synthesis at the translocation step. In the present study, a novel type I ribosome-inactivating protein, termed PAP-H, was purified from Agrobacterium rhizogenes-transformed hairy roots of pokeweed (Phytolacca americana). The protein was purified by anion- and cation-exchange chromatography. PAP-H has a molecular mass of 29.5 kD as detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its isoelectric point was determined to be 7.8. Yeast (Saccharomyces cerevisiae) ribosomes incubated with PAP-H released the 360-nucleotide diagnostic fragment from the 26S rRNA upon aniline treatment, an indication of its ribosome-inactivating activity. Using immunofluorescence microscopy, PAP-H was found to be located in the cell walls of hairy roots and root border cells. PAP-H was determined to be constitutively secreted as part of the root exudates, with its secretion enhanced by a mechanism mediated by ethylene induction. Purified PAP-H did not show in vitro antifungal activity against soil-borne fungi. In contrast, root exudates containing PAP-H as well as additional chitinase, beta-1,3-glucanase, and protease activities did inhibit the growth of soil-borne fungi. We found that PAP-H depurinates fungal ribosomes in vitro and in vivo, suggesting an additive mechanism that enables PAP-H to penetrate fungal cells.
Collapse
Affiliation(s)
- Sang-Wook Park
- Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, Colorado 80523-1173, USA
| | | | | | | |
Collapse
|
18
|
Chen Y, Peumans WJ, Van Damme EJM. The Sambucus nigra type-2 ribosome-inactivating protein SNA-I' exhibits in planta antiviral activity in transgenic tobacco. FEBS Lett 2002; 516:27-30. [PMID: 11959096 DOI: 10.1016/s0014-5793(02)02455-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Transgenic tobacco (Samsun NN) plants transformed with a cDNA clone encoding SNA-I' from Sambucus nigra synthesize, and correctly process and assemble, a fully active type-2 ribosome-inactivating protein. Expression of SNA-I' under the control of the 35S cauliflower mosaic virus promoter enhances the plant's resistance against infection with tobacco mosaic virus. In contrast to type-1 ribosome-inactivating proteins, the expression of SNA-I' does not affect the growth and fertility of the transgenic plants and is not accompanied by an increased expression of pathogenesis-related proteins indicating that its antiviral activity most probably differs from that of pokeweed antiviral protein.
Collapse
Affiliation(s)
- Ying Chen
- Laboratory for Phytopathology and Plant Protection, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001, Leuven, Belgium
| | | | | |
Collapse
|
19
|
Peumans WJ, Hao Q, Van Damme EJ. Ribosome-inactivating proteins from plants: more than RNA N-glycosidases? FASEB J 2001; 15:1493-506. [PMID: 11427481 DOI: 10.1096/fj.00-0751rev] [Citation(s) in RCA: 210] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Many plants contain proteins that are capable of inactivating ribosomes and accordingly are called ribosome-inactivating proteins or RIPs. These typical plant proteins receive a lot of attention in biological and biomedical research because of their unique biological activities toward animal and human cells. In addition, evidence is accumulating that some RIPs play a role in plant defense and hence can be exploited in plant protection. To understand the mode of action of RIPs and to optimize their medical and therapeutical applications and their use as antiviral compounds in plant protection, intensive efforts have been made to unravel the enzymatic activities of RIPs and provide a structural basis for these activities. Though marked progress has been made during the last decade, the enzymatic activity of RIPs has become a controversial issue because of the concept that RIPs possess, in addition to their classical RNA N-glycosidase and polynucleotide:adenosine glycosidase activity, other unrelated enzymatic activities. Moreover, the presumed novel enzymatic activities, especially those related to diverse nuclease activities, are believed to play an important role in various biological activities of RIPs. However, both the novel enzymatic activities and their presumed involvement in the biological activities of RIPs have been questioned because there is evidence that the activities observed are due to contaminating enzymes. We offer a critical review of the pros and cons of the putative novel enzymatic activities of RIPs. Based on the available data, it is suggested that there is little conclusive evidence in support of the presumed activities and that in the past too little attention has been given to the purity of the RIP preparation. The antiviral activity and mode of action of RIPs in plants are discussed in view of their classical and presumed novel enzymatic activities.
Collapse
Affiliation(s)
- W J Peumans
- Laboratory of Phytopathology and Plant Protection, Katholieke Universiteit Leuven, 3001 Leuven, Belgium
| | | | | |
Collapse
|
20
|
Affiliation(s)
- P Wang
- Biotechnology Center for Agriculture and the Environment, Rutgers University, New Brunswick, New Jersey 08901, USA
| | | |
Collapse
|
21
|
Zoubenko O, Hudak K, Tumer NE. A non-toxic pokeweed antiviral protein mutant inhibits pathogen infection via a novel salicylic acid-independent pathway. PLANT MOLECULAR BIOLOGY 2000; 44:219-29. [PMID: 11117265 DOI: 10.1023/a:1006443626864] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Pokeweed antiviral protein (PAP), a ribosome-inactivating protein isolated from Phytolacca americana, is characterized by its ability to depurinate the sarcin/ricin (S/R) loop of the large rRNA of prokaryotic and eukaryotic ribosomes. In this study, we present evidence that PAP is associated with ribosomes and depurinates tobacco ribosomes in vivo by removing more than one adenine and a guanine. A mutant of pokeweed antiviral protein, PAPn, which has a single amino acid substitution (G75D), did not bind ribosomes efficiently, indicating that Gly-75 in the N-terminal domain is critical for the binding of PAP to ribosomes. PAPn did not depurinate ribosomes and was non-toxic when expressed in transgenic tobacco plants. Unlike wild-type PAP and a C-terminal deletion mutant, transgenic plants expressing PAPn did not have elevated levels of acidic pathogenesis-related (PR) proteins. PAPn, like other forms of PAP, did not trigger production of salicylic acid (SA) in transgenic plants. Expression of the basic PR proteins, the wound-inducible protein kinase and protease inhibitor II, was induced in PAPn-expressing transgenic plants and these plants were resistant to viral and fungal infection. These results demonstrate that PAPn activates a particular SA-independent, stress-associated signal transduction pathway and confers pathogen resistance in the absence of ribosome binding, rRNA depurination and acidic PR protein production.
Collapse
Affiliation(s)
- O Zoubenko
- Department of Plant Pathology, Cook College, Rutgers University, New Brunswick, NJ 08903, USA
| | | | | |
Collapse
|
22
|
Balasubrahmanyam A, Baranwal VK, Lodha ML, Varma A, Kapoor HC. Purification and properties of growth stage-dependent antiviral proteins from the leaves of Celosia cristata. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2000; 154:13-21. [PMID: 10725554 DOI: 10.1016/s0168-9452(99)00192-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two antiviral glycoproteins, active against mechanical transmission of two tobamoviruses, tobacco mosaic virus and sunnhemp rosette virus, and citrus ring spot virus (ungrouped), were purified from the dried leaves of Celosia cristata. These proteins, called CCP-25 and CCP-27, have M(r) 25 and 27 kDa, respectively. Their concentration was found to vary between the pre-flowering and post-flowering stages of C. cristata90% lesion formation at a concentration of 20-30 µg ml(-1). They were resistant to proteases in the native state, but were readily digested when denatured. Both of them imparted actinomycin D sensitive resistance by inhibiting local lesions on Nicotiana tabacum cv. Samsun NN by tobacco mosaic virus. Their application, individually, also resulted in high resistance in systemic hosts to sunnhemp rosette virus, and citrus ring spot virus, respectively.
Collapse
Affiliation(s)
- A Balasubrahmanyam
- Division of Biochemistry, Indian Agricultural Research Institute, Pusa, New Delhi, India
| | | | | | | | | |
Collapse
|
23
|
Tumer NE, Hudak K, Di R, Coetzer C, Wang P, Zoubenko O. Pokeweed antiviral protein and its applications. Curr Top Microbiol Immunol 1999; 240:139-58. [PMID: 10394719 DOI: 10.1007/978-3-642-60234-4_7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- N E Tumer
- Department of Plant Pathology, Rutgers University, New Brunswick, NJ 08901-8520, USA
| | | | | | | | | | | |
Collapse
|
24
|
Abstract
In recent years, plant biotechnology has almost reached maturity. Transgenic plants engineered to be herbicide- or insect-resistant are outcompeting conventional crop plants and pest managing strategies leading to a major rethinking of the chemical industry. Due to worldwide efforts to study genome function, almost any gene of interest is, or will soon be available. Thus, identification of gene function will be the major challenge of the next few years. In combination with established gene-delivery systems and desired promoter and targetting sequences, gene discovery will open a fascinating and new field of crop plant design. Transgenic plants engineered to produce superior polypeptides have already been created and the first examples are entering clinical and industrial trials.
Collapse
Affiliation(s)
- K Herbers
- SunGene GmbH and Co. KGaA, Corrensstrasse 3, 06466 Gatersleben, Germany.
| | | |
Collapse
|
25
|
Abstract
Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are independent of salicylic acid. Evidence is emerging that jasmonic acid and ethylene play key roles in these salicylic acid-independent pathways. Cross-talk between the salicylic acid-dependent and the salicylic acid-independent pathways provides great regulatory potential for activating multiple resistance mechanisms in varying combinations.
Collapse
Affiliation(s)
- CM Pieterse
- Section of Plant Pathology, Dept of Plant Ecology and Evolutionary Biology, Utrecht University, PO Box 800.84, 3508 TB Utrecht, The Netherlands
| |
Collapse
|
26
|
Wang P, Zoubenko O, Tumer NE. Reduced toxicity and broad spectrum resistance to viral and fungal infection in transgenic plants expressing pokeweed antiviral protein II. PLANT MOLECULAR BIOLOGY 1998; 38:957-64. [PMID: 9869402 DOI: 10.1023/a:1006084925016] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pokeweed antiviral protein II (PAPII), a 30 kDa protein isolated from leaves of Phytolacca americana, inhibits translation by catalytically removing a specific adenine residue from the large rRNA of the 60S subunit of eukaryotic ribosomes. The protein sequence of PAPII shows only 41% identity to PAP and PAP-S, two other antiviral proteins isolated from pokeweed. We isolated a cDNA corresponding to PAPII and introduced it into tobacco plants. PAPII expressed in transgenic tobacco was correctly processed to the mature form as in pokeweed and accumulated to at least 10-fold higher levels than wild-type PAP. We had previously observed a significant decrease in transformation frequency with PAP and recovered only two transgenic lines expressing 1-2 ng per mg protein. In contrast, eight different transgenic lines expressing up to 250 ng/mg PAPII were recovered, indicating that PAPII is less toxic than PAP. Two symptomless transgenic lines expressing PAPII were resistant to tobacco mosaic virus, potato virus X and the fungal pathogen Rhizoctonia solani. The level of viral and fungal resistance observed correlated well with the amount of PAPII protein accumulated. Pathogenesis-related protein PR1 was constitutively expressed in transgenic lines expressing PAPII. Although PR1 was constitutively expressed, no increase in salicylic acid levels was detected, indicating that PAPII may elicit a salicylic acid-independent signal transduction pathway.
Collapse
Affiliation(s)
- P Wang
- Biotechnology Center for Agriculture and the Environment and Department of Plant Pathology, Rutgers University, New Brunswick, NJ 08901-8520, USA
| | | | | |
Collapse
|
27
|
|
28
|
Zoubenko O, Uckun F, Hur Y, Chet I, Tumer N. Plant resistance to fungal infection induced by nontoxic pokeweed antiviral protein mutants. Nat Biotechnol 1997; 15:992-6. [PMID: 9335052 DOI: 10.1038/nbt1097-992] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pokeweed antiviral protein (PAP), a 29-kD protein isolated from Phytolacca americana inhibits translation by catalytically removing a specific adenine residue from the large rRNA of the 60S subunit of eukaryotic ribosomes. Transgenic plants expressing PAP are resistant to a broad spectrum of plant viruses. Nontoxic PAP mutants have been isolated by random mutagenesis and selection in yeast. One of these mutants, PAP-X, had a point mutation at the active-site (E176V) that abolished enzymatic activity, and another mutant, delta C25PAP, had a nonsense mutation near the C-terminus (W237stop) that deleted 25 C-terminal amino acids. Unlike the wild-type PAP, expression of neither mutant was toxic to transgenic plants. We show that both class I (basic) and class II (acidic) isoforms of pathogenesis-related (PR) proteins are overexpressed in transgenic plants expressing PAP and the nontoxic PAP mutants. Although PR-proteins are constitutively expressed, no increase in salicylic acid levels was detected. Homozygous progeny of transgenic plants expressing either PAP or the nontoxic PAP mutants displayed resistance to the fungal pathogen Rhizoctonia solani. These results show that expression of PAP or the nontoxic PAP mutants activates multiple plant defense pathways independently of salicylic acid and confers resistance to fungal infection. The C-terminal 25 amino acids of PAP, which are required for toxicity in vivo, are not critical for resistance to viral or fungal infection, indicating that toxicity of PAP can be separated from pathogen resistance.
Collapse
Affiliation(s)
- O Zoubenko
- Agricultural Biotechnology Center, Rutgers University, Cook College, New Brunswick, NJ 08903-0231, USA
| | | | | | | | | |
Collapse
|