Epiphytic fungi induced pathogen resistance of invasive plant Ipomoea cairica against Colletotrichum gloeosporioides

Background Ipomoea cairica (L.) Sweet is a destructive invasive weed in South China but rarely infected with pathogens in nature. Its pathogen resistance mechanism is largely unknown at present. Some non-pathogenic isolates of Fusarium oxysporum and Fusarium fujikuroi are prevalent on many plant species and function as pathogen resistance inducers of host plants. The objective of the present research is to investigate whether the symbiosis between the both fungi and I. cairica is present, and thereby induces pathogen resistance of I. cairica. Methods Through field investigation, we explored the occurrence rates of F. oxysporum and F. fujikuroi on leaf surfaces of I. cairica plants in natural habitats and compared their abundance between healthy leaves and leaves infected with Colletotrichum gloeosporioides, a natural pathogen. With artificial inoculation, we assessed their pathogenicity to I. cairica and studied their contribution of pathogen resistance to I. cairica against C. gloeosporioides. Results We found that F. oxysporum and F. fujikuroi were widely epiphytic on healthy leaf surfaces of I. cairica in sunny non-saline, shady non-saline and sunny saline habitats. Their occurrence rates reached up to 100%. Moreover, we found that the abundance of F. oxysporum and F. fujikuroi on leaves infected with C. gloeosporioides were significantly lower than that of healthy leaves. With artificial inoculation, we empirically confirmed that F. oxysporum and F. fujikuroi were non-pathogenic to I. cairica. It was interesting that colonization by F. fujikuroi, F. oxysporum alone and a mixture of both fungi resulted in a reduction of C. gloeosporioides infection to I. cairica accompanied by lower lesion area to leaf surface area ratio, increased hydrogen peroxide (H2O2) concentration and salicylic acid (SA) level relative to the control. However, NPR1 expression, chitinase and β-1,3-glucanase activities as well as stem length and biomass of I. cairica plant only could be significantly improved by F. oxysporum and a mixture of both fungi but not by F. fujikuroi. In addition, as compared to colonization by F. oxysporum and a mixture of both fungi, F. fujikuroi induced significantly higher jasmonic acid (JA) level but significantly lower β-1,3-glucanase activity in leaves of I. cairica plants. Thus, our findings indicated the symbiosis of epiphytic fungiF. fujikuroi and F. oxysporum induced systemic resistance of I. cairica against C. gloeosporioides. F. oxysporum played a dominant role in inducing pathogen resistance of I. cairica. Its presence alleviated the antagonism of the JA signaling on SA-dependent β-1,3-glucanase activity and enabled I. cairica plants to maintain relatively higher level of resistance against C. gloeosporioides.

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Epiphytic fungi induced pathogen resistance of invasive plant Ipomoea cairica against Colletotrichum gloeosporioides

10.7287/peerj.preprints.27956 ◽

2019 ◽

Author(s):

Hua Xu ◽

Minjie Zhu ◽

Shaoshan Li ◽

Weibin Ruan ◽

Can Xie

Keyword(s):

Colletotrichum Gloeosporioides ◽

Pathogen Resistance ◽

Artificial Inoculation ◽

Stem Length ◽

Systemic Resistance ◽

Fusarium Fujikuroi ◽

Natural Habitats ◽

Glucanase Activity ◽

Epiphytic Fungi ◽

Leaf Surfaces

Background. Ipomoea cairica (L.) Sweet is a destructive invasive weed in South China but rarely infected with pathogens in nature. Its pathogen resistance mechanism is largely unknown at present. Some non-pathogenic isolates of Fusarium oxysporum and Fusarium fujikuroi are prevalent on many plant species and function as pathogen resistance inducers of host plants. The objective of the present research is to investigate whether the symbiosis between the both fungi and I. cairica is present, and thereby induce pathogen resistance of I. cairica. Methods. Through field investigation, we explored the occurrence rates of F. oxysporum and F. fujikuroi on leaf surfaces of I. cairica plants in natural habitats and compared their abundance between healthy leaves and leaves infected with Colletotrichum gloeosporioides, a natural pathogen. With artificial inoculation, we assessed their pathogencity to I. cairica and study their contribution of pathogen resistance to I. cairica against C. gloeosporioides. Results. We found that F. oxysporum and F. fujikuroi were widely epiphytic on healthy leaf surfaces of I. cairica in sunny non-saline, shady non-saline and sunny saline habitats. Their occurrence rates reached up to 100%. Moreover, we found that the abundance of F. oxysporum and F. fujikuroi on leaves infected with C. gloeosporioides were significantly lower than that of healthy leaves. With artificial inoculation, we empirically confirmed that F. oxysporum and F. fujikuroi were non-pathogenic to I. cairica. It was interesting that colonization by F. fujikuroi, F. oxysporum alone and a mixture of both fungi resulted in a reduction of C. gloeosporioides infection to I. cairica accompanied by lower lesion area to leaf surface area ratio, increased H2O2 concentration and salicylic acid (SA) level relative to the control. However, NPR1 expression, chitinase and β -1,3-glucanase activities as well as stem length and biomass of I. cairica plant only could be significantly improved by F. oxysporum and a mixture of both fungi but not by F. fujikuroi. In addition, as compared to colonization by F. oxysporum and a mixture of both fungi, F. fujikuroi induced significantly higher jasmonic acid (JA) level but significantly lower β -1,3-glucanase activity in leaves of I. cairica plants. Thus, our findings indicated the symbiosis of epiphytic fungi F. fujikuroi and F. oxysporum facilitated the fitness of I. cairica via the induced systemic resistance of host plant against C. gloeosporioides. F. oxysporum played a dominant role in inducing pathogen resistance of I. cairica. Its presence alleviated the antagonism of the JA signaling on SA-dependent β -1,3-glucanase activity and enabled I. cairica plants to maintain relatively higher level of resistance against C. gloeosporioides.

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Epiphytic fungi induced pathogen resistance of invasive plant Ipomoea cairica against Colletotrichum gloeosporioides

10.7287/peerj.preprints.27956v1 ◽

2019 ◽

Author(s):

Hua Xu ◽

Minjie Zhu ◽

Shaoshan Li ◽

Weibin Ruan ◽

Can Xie

Keyword(s):

Colletotrichum Gloeosporioides ◽

Pathogen Resistance ◽

Artificial Inoculation ◽

Stem Length ◽

Systemic Resistance ◽

Fusarium Fujikuroi ◽

Natural Habitats ◽

Glucanase Activity ◽

Epiphytic Fungi ◽

Leaf Surfaces

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Exogenous Application of Harpin Protein Hpa1 onto Pinellia ternata Induces Systemic Resistance Against Tobacco Mosaic Virus

Phytopathology ◽

10.1094/phyto-12-19-0463-r ◽

2020 ◽

Vol 110 (6) ◽

pp. 1189-1198

Author(s):

Defu Wang ◽

Baoxia Wang ◽

Jiangran Wang ◽

Shuting Wang ◽

Weiyu Wang ◽

...

Keyword(s):

Disease Resistance ◽

Tobacco Mosaic Virus ◽

Mosaic Virus ◽

Large Scale ◽

Pathogen Resistance ◽

Field Application ◽

Systemic Resistance ◽

Pinellia Ternata ◽

Related Substances ◽

Harpin Protein

The harpin protein Hpa1 has various beneficial effects in plants, such as promoting plant growth and inducing pathogen resistance. Our previous study found that Hpa1 could significantly alleviate the mosaic symptoms of tobacco mosaic virus (TMV) in Pinellia ternata, indicating that Hpa1 can effectively stimulate resistance. Here, the potential mechanism of disease resistance and field applicability of Hpa1 against TMV in P. ternata were further investigated. The results showed that 15 µg ml−1 Hpa1 had stronger antiviral activity than the control, and its protective effect was better than its curative effect. Furthermore, Hpa1 could significantly induce an increase in defense-related enzyme activity, including polyphenol oxidase, peroxidase, catalase, and superoxide dismutase, as well as increase the expression of disease resistance-related genes (PR1, PR3, PR5, and PDF1.2). Concurrently, Hpa1 significantly increased the content of some disease resistance-related substances, including hydrogen peroxide, phenolics, and callose, whereas the content of malondialdehyde was reduced. In addition, field application analysis demonstrated that Hpa1 could effectively elicit a defense response against TMV in P. ternata. Our findings propose a mechanism by which Hpa1 can prevent TMV infection in Pinellia by inducing systemic resistance, thereby providing an environmentally friendly approach for the use of Hpa1 in large-scale applications to improve TMV resistance in Pinellia.

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First Report of Anthracnose of Tricyrtis macropoda Caused by Colletotrichum gloeosporioides in Korea

Plant Disease ◽

10.1094/pdis-03-12-0277-pdn ◽

2012 ◽

Vol 96 (7) ◽

pp. 1070-1070 ◽

Cited By ~ 1

Author(s):

J. H. Park ◽

K. S. Han ◽

Y. D. Kwon ◽

H. D. Shin

Keyword(s):

Colletotrichum Gloeosporioides ◽

Morphological Characteristics ◽

Its Region ◽

Culture Collection ◽

Perennial Herb ◽

Pathogenicity Test ◽

Conidial Suspension ◽

Natural Habitats ◽

First Report ◽

Small Water

Tricyrtis macropoda Miq. (syn. T. dilatata Nakai), known as speckled toadlily, is a perennial herb native to China, Japan, and Korea. The plant has been highly praised for its beautiful flowers and rare populations in natural habitats. In September 2006, several dozen plants were heavily damaged by leaf spots and blight in cultivated plantings in the city of Pocheon, Korea. The infections with the same symptoms were repeated every year. In July 2011, the same symptoms were found on T. macropoda in the cities of Gapyeong and Osan, Korea. The leaf lesions began as small, water-soaked, pale greenish to grayish spots, which enlarged to form concentric rings and ultimately coalesced. A number of blackish acervuli were formed in the lesions. Acervuli were mostly epiphyllous, circular to ellipsoid, and 40 to 200 μm in diameter. Setae were two- to three-septate, dark brown at the base, paler upwards, acicular, and up to 100 μm long. Conidia (n = 30) were long obclavate to oblong-elliptical, sometimes fusiform-elliptical, guttulate, hyaline, and 12 to 20 × 4 to 6.5 μm (mean 15.4 × 5.2 μm). These morphological characteristics of the fungus were consistent with the description of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (2). Voucher specimens (n = 7) were deposited in the Korea University herbarium (KUS). Two isolates, KACC46374 (ex KUS-F25916) and KACC46405 (ex KUS-F26063), were deposited in the Korean Agricultural Culture Collection. Fungal DNA was extracted and the complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced. The resulting sequences of 549 bp were deposited in Genbank (Accession Nos. JQ619480 and JQ619481). They showed 100% similarity with a sequence of C. gloeosporioides (EU32619). Isolate KACC46374 was used in a pathogenicity test. Inoculum was prepared by harvesting conidia from 3-week-old cultures on potato dextrose agar. A conidial suspension (2 × 106 conidia/ml) was sprayed onto 15 leaves of three plants. Three noninoculated plants served as controls. Plants were covered with plastic bags to maintain 100% relative humidity for 24 h and then kept in a greenhouse (22 to 28°C and 70 to 80% RH). After 5 days, typical leaf spot symptoms, identical to the ones observed in the field, started to develop on the leaves of inoculated plants. No symptoms were observed on control plants. C. gloeosporioides was reisolated from the lesions of inoculated plants, thus fulfilling Koch's postulates. An anthracnose associated with C. tricyrtii (Teng) Teng was recorded on T. formosana and T. latifolia in China (3) and on T. formosana in Taiwan (1), respectively, without etiological studies. The morphological features of C. tricyrtii are within the variation of C. gloeosporioides (2). To our knowledge, this is the first report of anthracnose of T. macropoda. This report has significance to indigenous plant resource conservation managers and scientists because T. macropoda has been listed as one of the 126 “Rare and Endangered Plants” by the Korea Forest Service since 1991. References: (1) K. Sawada. Rep. Dept. Agric. Gov. Res. Inst. Formosa 87: 1, 1944. (2) B. C. Sutton. Pages 1–27 in: Colletotrichum Biology, Pathology and Control. J. A. Bailey and M. J. Jeger, eds. CAB International, Wallingford, U.K. 1992. (3) S. C. Teng. Contrib. Biol. Lab. Sci. Soc. China 8:36, 1932.

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Control of Postharvest Decay of Apple Fruit with Candida saitoana and Induction of Defense Responses

Phytopathology ◽

10.1094/phyto.2003.93.3.344 ◽

2003 ◽

Vol 93 (3) ◽

pp. 344-348 ◽

Cited By ~ 107

Author(s):

Ahmed El Ghaouth ◽

Charles L. Wilson ◽

Michael Wisniewski

Keyword(s):

Botrytis Cinerea ◽

Defense Responses ◽

Apple Fruit ◽

Antagonistic Activity ◽

Systemic Resistance ◽

Induce Systemic Resistance ◽

Lesion Development ◽

Glucanase Activity ◽

Induce Resistance ◽

Lag Period

The ability of Candida saitoana to induce systemic resistance in apple fruit against Botrytis cinerea was investigated. To separate the antagonistic activity of C. saitoana from its ability to induce resistance, the antagonist and the pathogen were applied in spatially separated wounds. In fresh apples, C. saitoana applied 0 or 24 h before inoculation with B. cinerea showed no effect on lesion development caused by B. cinerea. When applied 48 to 72 h preinoculation with B. cinerea, however, C. saitoana reduced lesion diameter by more than 50 and 70%, respectively, compared with wounding. C. saitoana had no effect on lesion development on stored apples, regardless of the lag period between yeast treatment and inoculation with B. cinerea. In addition to inducing systemic resistance, C. saitoana increased chitinase and β-1,3-glucanase activities with a higher accumulation in fresh than in stored apples. In fresh apples, the onset of systemic resistance to B. cinerea coincided with the increase in chitinase and β-1,3-glucanase activity in systemically protected tissue. These studies show that C. saitoana is capable of inducing systemic resistance in apple fruit and indirectly suggest that antifungal hydrolases are involved in the observed systemic protection.

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Melatonin Mitigates the Infection of Colletotrichum gloeosporioides via Modulation of the Chitinase Gene and Antioxidant Activity in Capsicum annuum L.

Antioxidants ◽

10.3390/antiox10010007 ◽

2020 ◽

Vol 10 (1) ◽

pp. 7

Author(s):

Muhammad Ali ◽

Anthony Tumbeh Lamin-Samu ◽

Izhar Muhammad ◽

Mohamed Farghal ◽

Abdul Mateen Khattak ◽

...

Keyword(s):

Antioxidant Enzymes ◽

Steady State ◽

Colletotrichum Gloeosporioides ◽

State Level ◽

Pathogen Resistance ◽

Chitinase Gene ◽

Pathogenesis Related ◽

Steady State Levels ◽

Plant Pathogen Interactions ◽

Pepper Plants

Anthracnose, caused by Colletotrichum gloeosporioides, is one of the most damaging pepper (Capsicum annum L.) disease. Melatonin induces transcription of defense-related genes that enhance resistance to pathogens and mediate physiological activities in plants. To study whether the melatonin-mediated pathogen resistance is associated with chitinase gene (CaChiIII2), pepper plants and Arabidopsis seeds were treated with melatonin, then CaChiIII2 activation, hydrogen peroxide (H2O2) levels, and antioxidant enzymes activity during plant–pathogen interactions were investigated. Melatonin pretreatment uncoupled the knockdown of CaChiIII2 and transiently activated its expression level in both control and CaChiIII2-silenced pepper plants and enhanced plant resistance. Suppression of CaChiIII2 in pepper plants showed a significant decreased in the induction of defense-related genes and resistance to pathogens compared with control plants. Moreover, melatonin efficiently enabled plants to maintain intracellular H2O2 concentrations at steady-state levels and enhanced the activities of antioxidant enzymes, which possibly improved disease resistance. The activation of the chitinase gene CaChiIII2 in transgenic Arabidopsis lines was elevated under C. gloeosporioides infection and exhibited resistance through decreasing H2O2 biosynthesis and maintaining H2O2 at a steady-state level. Whereas melatonin primed CaChiIII2-overexpressed (OE) and wild-type (WT) Arabidopsis seedlings displayed a remarkable increase in root-length compared to the unprimed WT plants. Using an array of CaChiIII2 knockdown and OE, we found that melatonin efficiently induced CaChiIII2 and other pathogenesis-related genes expressions, responsible for the innate immunity response of pepper against anthracnose disease.

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Problems and Prospects of Improving Abiotic Stress Tolerance and Pathogen Resistance of Oil Palm

Plants ◽

10.3390/plants10122622 ◽

2021 ◽

Vol 10 (12) ◽

pp. 2622

Author(s):

Lu Wei ◽

Jerome Jeyakumar John Martin ◽

Haiqing Zhang ◽

Ruining Zhang ◽

Hongxing Cao

Keyword(s):

Stress Tolerance ◽

Oil Palm ◽

Abiotic Stress Tolerance ◽

Crop Productivity ◽

Pathogen Resistance ◽

Climatic Conditions ◽

Stress Factors ◽

Research Progress ◽

Natural Habitats ◽

Existing Problems

Oil palm crops are the most important determinant of the agricultural economy within the segment of oilseed crops. Oil palm growing in their natural habitats are often challenged simultaneously by multiple stress factors, both abiotic and biotic that limit crop productivity and are major constraints to meeting global food demands. The stress-tolerant oil palm crops that mitigate the effects of abiotic stresses on crop productivity are crucially needed to sustain agricultural production. Basal stem rot threatens the development of the industry, and the key to solving the problem is to breed new oil palm varieties resistant to adversity. This has created a need for genetic improvement which involves evaluation of germplasm, pest and disease resistance, earliness and shattering resistance, quality of oil, varieties for different climatic conditions, etc. In recent years, insights into physiology, molecular biology, and genetics have significantly enhanced our understanding of oil palm response towards such stimuli as well as the reason for varietal diversity in tolerance. In this review, we explore the research progress, existing problems, and prospects of oil palm stress resistance-based physiological mechanisms of stress tolerance as well as the genes and metabolic pathways that regulate stress response.

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SYSTEMIC RESISTANCE INDUCERS APPLIED PREHARVEST FOR COLLETOTRICHUM GLOEOSPORIOIDES CONTROL IN AVOCADOS

Acta Horticulturae ◽

10.17660/actahortic.2013.1007.14 ◽

2013 ◽

pp. 153-160 ◽

Cited By ~ 2

Author(s):

R.J. Bosse ◽

J.P. Bower ◽

I. Bertling

Keyword(s):

Colletotrichum Gloeosporioides ◽

Systemic Resistance ◽

Resistance Inducers

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The gene cutA of Fusarium fujikuroi, encoding a protein of the haloacid dehalogenase family, is involved in osmotic stress and glycerol metabolism

Microbiology ◽

10.1099/mic.0.071761-0 ◽

2014 ◽

Vol 160 (1) ◽

pp. 26-36 ◽

Cited By ~ 5

Author(s):

Jorge García-Martínez ◽

Marta Castrillo ◽

Javier Avalos

Keyword(s):

Stress Response ◽

Osmotic Stress ◽

Osmotic Shock ◽

Phytopathogenic Fungus ◽

Glycerol Dehydrogenase ◽

Glycerol Metabolism ◽

Fusarium Fujikuroi ◽

Mrna Levels ◽

Natural Habitats ◽

Haloacid Dehalogenase

Survival of micro-organisms in natural habitats depends on their ability to adapt to variations in osmotic conditions. We previously described the gene cut-1 of Neurospora crassa, encoding a protein of the haloacid dehalogenase family with an unknown function in the osmotic stress response. Here we report on the functional analysis of cutA, the orthologous gene in the phytopathogenic fungus Fusarium fujikuroi. cutA mRNA levels increased transiently after exposure to 0.68 M NaCl and were reduced upon return to normal osmotic conditions; deletion of the gene resulted in a partial reduction in tolerance to osmotic stress. ΔcutA mutants contained much lower intracellular levels of glycerol than the wild-type, and did not exhibit the increase following hyper-osmotic shock expected from the high osmolarity glycerol (HOG) response. cutA is linked and divergently transcribed with the putative glycerol dehydrogenase gene gldB, which showed the same regulation by osmotic shock. The intergenic cutA/gldB regulatory region contains putative stress-response elements conserved in other fungi, and both genes shared other regulatory features, such as induction by heat shock and by illumination. Photoinduction was also observed in the HOG response gene hogA, and was lost in mutants of the white collar gene wcoA. Previous data on glycerol production in Aspergillus spp. and features of the predicted CutA protein lead us to propose that F. fujikuroi produces glycerol from dihydroxyacetone, and that CutA is the enzyme involved in the synthesis of this precursor by dephosphorylation of dihydroxyacetone-3P.

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Variations in heat resistance of ecotypes of Eucalyptus camaldulensis Dehn. and their significance

Australian Journal of Botany ◽

10.1071/bt9710261 ◽

1971 ◽

Vol 19 (3) ◽

pp. 261 ◽

Cited By ~ 6

Author(s):

R Karschon ◽

L Pinchas

Keyword(s):

Heat Resistance ◽

Eucalyptus Camaldulensis ◽

Seed Source ◽

Maximum Temperature ◽

Natural Habitats ◽

Leaf Surfaces ◽

The Mean ◽

Wax Deposits ◽

Resistance Value ◽

Seed Provenance

Depending upon the seed provenance, the heat resistance value of leaves of E. carnaldulensis varies from 47.4 to 50.0°C. It is not related to the mean maximum temperature of the hottest month at the seed source. The relation of heat resistance to wax deposits, colour, and temperatures of leaf surfaces is examined. The implications of the findings in the phylogeny and ecotypic divergence of the species and its cultivation outside its natural habitats in Australia are discussed.

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