Phytohormones Producing Fungal Endophytes Enhance Nutritional Status and Suppress Pathogenic Fungal Infection in Tomato

Document Type : Original Research

Authors
1 Pesticide Chemistry and Technology Department, Faculty of Agriculture, El-Shatby, Alexandria University, Alexandria 21545, Egypt
2 Soil and Water Science Department, Faculty of Agriculture, El-Shatby, Alexandria University, Alexandria 21545, Egypt
Abstract
Two endophytic fungi, namely, Curvularia lunata and Nigrospora sphaerica, were isolated from Melia azedarach, an exotic tree introduced in Egypt from Asia. The fungal endophytes were identified by microscopic examination and molecular identification of nucleotide sequence by DNA sequencing of the purified PCR product. Their antagonistic activities against phytopathogenic fungi and their ability to produce important growth hormone and providing some necessary nutrients for plant growth were also evaluated. Both endophytes exhibited antagonistic activities: C. lunata caused 56% and 50% growth inhibition of Alternaria solani and Fusarium oxysporum, while N. sphaerica suppressed both pathogenic fungi by 63.4% and 56.6%, respectively. N. sphaerica was able to dissolve insoluble phosphorus, produce ammonia, and secrete 40 µg mL-1 of IAA. In contrast, C. lunata failed to dissolve phosphorus, secreted less amount of IAA (3 µg mL-1), but produced ammonia. A greenhouse pot experiment was conducted using phosphorus deficient soil to find out the ability of both endophytes to improve growth of tomato plants. N. sphaerica significantly increased shoot fresh weight by 13% and 22% over C. lunata and the control, respectively. Concerning the nutritional status of tomato plants, both endophytes led to significant increase in nitrogen concentration in shoots when applying 50% of the recommended mineral fertilizer. N. sphaerica enhanced phosphorus concentration in shoots by 13% over the control. Finally, the antifungal activities of both endophytes against F. oxysporum in tomato plants were tested under glasshouse conditions. N. sphaerica was more potent than C. lunata in suppressing 40% of F. oxysporum infection and had positive impact on tomato plant growth. Our study results highlight the potential use of N. sphaerica endophytic fungi as plant biofertilizers and bio-control agent under glasshouse conditions.

Keywords


Akholiya, K.B.R. and Khunt M.D. 2015. Plant growth- promoting endophytes. Int. J. Pure App. Biosci. 3: 86-91.
Azevedo, J.L. and Araújo, W.L. 2006. Fungi: Multifaceted Microbes. In: Diversity and Applications of Endophytic Fungi Isolated from Tropical Plants (Ganguli BN and Deshmukh SK, eds.). Anamaya Publishers, New Dehli, 189-207.
Barnett, H.L. and Hunter, B.B. 1998. Illustrated genera of imperfect fungi. American Phytopathological Society, 4th edition
Bremner, J.M. and Mulvaney, C.S. 1982. Nitrogen- Total. In A.L. Page et al. (eds.) Methods of Soil Analysis. Part 2. Agron. J. 9: 595-624.
Cohort Software Inc, 1985. Costat User's Manual. Version 3 Cohort Tucson, Arizona, USA.
Dos Santos, R.M.G. and Rodrigues–Fo, E. 2003. Further meroterpenes produced by Penicillium sp., an endophyte obtained from Melia azedarach. Z. Naturforsch.C 58: 663–669
Egamberdieva, D., Jabborova, D. and Berg G. 2016. Synergistic interactions between Bradyrhizobium japonicum and the endophyte Stenotrophomonas rhizophila and their effects on growth, and nodulation of soybean under salt stress. Plant Soil; 405:35–45
Egamberdieva, D., Wirth, S.J., Shurigin, V.V., Hashem, A. and Abd-Allah, E.F. 2017. Endophytic Bacteria Improve Plant Growth, Symbiotic Performance of Chickpea (Cicer arietinum L.) and Induce Suppression of Root Rot Caused by Fusarium solani under salt stress. Front. Microbiol. 8:1887.
Fokkema, N.J. 1978. Fungal antagonism in the phylosphere. Ann. Appl. Biol. 89:115-117
Glick, B.R., Cheng, Z., Czarny, J. and Duan, J. 2007. Promotion of plant growth by ACC deaminase-producing soil bacteria, Eur. J. Plant Pathol. 119: 329– 339
Glickmann, E. and Dessaux, Y. 1995. A critical examination of the specificity of the salkowski reagent for indolic compounds produced by phytopathogenic bacteria. Appl. Environ. Microbiol. 61:793–6.
Horneck, D.A. and Hanson, D. 1998. Determination of potassium and sodium by flame emission spectrophotometry. Handbook of reference methods for plant analysis. 19: 153-155.
Illmer, P., Barbato, A. and Schinner, F. 1995. Solubilization of hardly- soluble AIPO4 with P- solubilizing microorganisms. Soil Biol. Biochem. 27: 265-270.
Jensen, H.L. 1942. Nitrogen fixation in leguminous plants II. Is symbiotic nitrogen fixation influenced by Azotobacter. Pro Line Soc NSW. 57:205–212.
Korsten, L. and De Jager, E.S. 1995. Mode of action of Bacillus subtilis for control of avocado post-harvest pathogens. S. Afr. Avocado Growers Assoc. Yearb, 18:124-130.
Lecomte, C., Alabouvette, C., Edel-Hermann, V., Robert, F. and Steinberg, C. 2016. Biological control of ornamental plant diseases caused by Fusarium oxysporum: a review. Biol. Control 101:17–30
Li, X., Geng, X., Xie, R., Fu, L., Jiang, J. and Gao, L. 2016. The endophytic bacteria isolated from elephant grass (Pennisetum purpureum Schumach) promote plant growth and enhance salt tolerance of Hybrid Pennisetum. Biotechnol. Biofuels. 9: 016–0592.
Louw, H.A., and Webley, D.M. 1958. A plate method for estimating the numbers of phosphate dissolving and acid production bacteria in soil. Nature (London) 182: 1317.
Mei, C. and Flinn, B.S. 2010. The use of beneficial microbial endophytes for plant biomass and stress tolerance improvement. Recent Pat. Biotech. 4:81–95
Murphy, J. and Riley, J.P. 1962. A modified single solution method for the determination of phosphate in natural waters. Anal. Chim. Acta. 27: 31 -36.
Naessens, J.M., Offord, K., Scott, W.F. and Daood, S.l. 1986. The MCSTRAT Procedure, in SUGI Supplemental Library User′s Guide, Version 5 Edition, Cary, NC: SAS Institute Inc., 307-328.
Ongena, M. and Jacques, P. 2008. Bacillus lipopeptides: versatile weapons for plant disease biocontrol. Trends Microbiol. 16: 115–125
Oteino, N., Lally, R.D., Kiwanuka, S., Lloyd, A., Ryan, D. and Germaine, K.J. 2015. Plant growth promotion induced by phosphate solubilizing endophytic Pseudomonas isolates. Front. Microbiol. 6:745.
Redman, R.S., Dunigan, D.D. and Rodriguez, R.J. 2001. Fungal symbiosis from mutualism to parasitism: who controls the outcome, host or invader? New Phytol. 151: 705–716.
Rybakova, D., Cernava, T., Köberl, M., Liebminger, S., Etemadi, M. and Berg, G. 2016. Endophytes-assisted biocontrol: novel insights in ecology and the mode of action of Paenibacillus. Plant Soil 405: 125–140.
Saad El-Din, H. 2017. Plant growth promoting activities for bacterial and fungal endophytes isolated from medicinal plant of Teucrium polium L. J. Advanc. Research 8: 687- 695.
Santos, I.P., Silva, L.C.N., Silva, M.V., Araúj, J.M., Cavalcanti, M.S. and Lima, V.L.M. 2015. Antibacterial activity of endophytic fungi from leaves of Indigofera suffruticosa Miller. (Fabaceae). Front. Microbiol. 6: 350-357
Servin, A.L. 2004. Antagonistic activities of lactobacilli and bifidobacteria against microbial pathogens. FEMS Microbiol. Rev. 28:405–440
Shahzad, R., Waqas, M., Khan, A.L., Asaf, S., Khan, M.A., Kang, S-M., Yun, B-W. and Lee, I-J. 2016. Seed-borne endophytic Bacillus amyloliquefaciens RWL-1 produces gibberellins and regulates endogenous phytohormones of Oryza sativa. Plant Physiol. Biochem. 106:236–243
Sunitha, V.H., Devi, D.N. and Srinivas, C. 2013. Extracellular enzymatic activity of endophytic fungal strains isolated from medicinal plants. World J. Agric. Sci. 9:1-9.
Szkop, M. and Bielwaski, W. 2013. A simple method for simultaneous RP-HPLC determination of indolic compounds related to bacterial biosynthesis. Antonie Van Leeuwenhoek 103:683-691.
Taktek, S., St-Arnaud, M., Piché, Y., Fortin, J.A. and Antoun, H. 2017. Igneous phosphate rock solubilization by biofilm-forming mycorrhizobacteria and hyphobacteria associated with Rhizoglomus irregulare DAOM 197198. Mycorrhiza. 27:13–22.
Tan, R.X., and Zou, W.X. 2001. Endophytes: a rich source of functional metabolites. Nat. Prod. Rep. 18: 448–459.
Torres, M.J., Brandan, C.P., Petroselli, G., Erra-Balsells, R. and Audisio, M.C. 2016. Antagonistic effects of Bacillus subtilis subsp. subtilis and B. amyloliquefaciens against Macrophomina phaseolina: SEM study of fungal changes and UV-MALDI-TOF MS analysis of their bioactive compounds. Microbiol. Res. 182: 31–39
Verma, V.C., Gond, S.K., Kumar, A., Kharwar R.N., Boulanger, L-A. and Strobel, G.A. 2011. Endophytic fungal flora from roots and fruits of an Indian neem plant Azadirachta indica A. Juss., and impact of culture media on their isolation. Indian J. Microbiol. 51: 469–476.
Zhao, J.H., Zhang, Y.L., Wang, L.W., Wang, J.Y. and Zhang, C.L. 2012. Bioactive secondary metabolites from Nigrospora sp. LLGLM003, an endophytic fungus of the medicinal plant Moringa oleifera Lam. World J. Microbiol. Biotechnol. 28: 2107–2112
Zhao, P., Quan, C., Wang, Y., Wang, J. and Fan, S. 2014. Bacillus amyloliquefaciens Q-426 as a potential biocontrol agent against Fusarium oxysporum f. sp. spinaciae. J Basic Microb. 54: 448–456