Effects of Epichloë festucae var. lolii on heavy metal stress tolerance of its perennial ryegrass host

Abstract

Background: The endophyte Epichloë festucae var. lolii forms mutualistic symbiosis with perennial ryegrass, and their relationship under heavy metal stress needs to be more clearly defined.

Methods: This study assessed the growth and physiological response of perennial ryegrass with (E+) and without endophyte (E−) under CdCl₂ (0, 50, 100, 200 mg L⁻¹) and ZnCl₂ (0, 500, 750, 1000 mg L⁻¹) treatments.

Results: Higher concentrations of CdCl₂ (200 mg L⁻¹) and ZnCl₂ (1000 mg L⁻¹) treatments typically suppressed ryegrass growth and physiological activity, but for many traits, particularly under ZnCl₂ stress, the presence of endophyte ameliorated heavy metal suppression. Specifically, E+ perennial ryegrass had significantly greater plant height, tiller number, biomass, water content, and root volume (p < 0.05) than E− perennial ryegrass under stress. Across the tested concentration ranges, a hormesis effect was observed for some ryegrass traits, and under Zn stress, the presence of endophyte enhanced the hormesis effect for malondialdehyde concentration.

Conclusions: These results indicate that Epichloë modulated growth and physiology to enhance heavy metal stress tolerance of its ryegrass host. The present study extends the understanding of how Epichloë endophyte forms a mutualistic symbiosis with perennial ryegrass.

Keywords

CdCl₂ treatment / Epichloë festucae var. lolii / malondialdehyde (MDA) concentration / perennial ryegrass / proline concentration / ZnCl₂ treatment

References

[1] Ahmed, M., & Farooq, S. (2013). Growth and physiological responses of wheat cultivars under various planting windows. Journal of Animal and Plant Sciences, 23,(5) 1407–1414.

[2] Ashraf, M., & Foolad, M. R. (2007). Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environmental and Experimental Botany, 59(2), 206–216. https://doi.org/10.1016/j.envexpbot.2005.12.006

[3] Ayangbenro, A., & Babalola, O. (2017). A new strategy for heavy metal polluted environments: A review of microbial biosorbents. International Journal of Environmental Research and Public Health, 14(1), 94. https://doi.org/10.3390/ijerph14010094.

[4] Bonnet, M., Camares, O., & Veisseire, P. (2000). Effects of zinc and influence of Acremonium lolii on growth parameters, chlorophyll a fluorescence and antioxidant enzyme activities of ryegrass (Lolium perenne L. cv. Apollo). Journal of Experimental Botany, 51(346), 945–953. https://doi.org/10.1093/jxb/51.346.945

[5] Caradus, J. R. (2024). Epichloë fungal endophytes–a vital component for perennial ryegrass survival in New Zealand. New Zealand Journal of Agricultural Research, 67(4), 451–468. https://doi.org/10.1080/00288233.2023.2170426

[6] Chaudhary, D. S., & Totawat, K. L. (1985). Zinc and phosphorus interaction on growth and nutrient uptake by wheat. Annals of Arid Zone, 24(1), 31–38. https://doi.org/10.56093/aaz.v24i1.64112

[7] Chen, Z. J., Jin, Y. Y., Yao, X., Chen, T. X., Wei, X. K., Li, C. J., White, J., & Nan, Z. B. (2020). Fungal endophyte improves survival of Lolium perenne in low fertility soils by increasing root growth, metabolic activity and absorption of nutrients. Plant and Soil, 452, 185–206. https://doi.org/10.1007/s11104-020-04556-7

[8] Chen, Z. J., Li, C. J., Nan, Z. B., White, J., Jin, Y. Y., & Wei, X. K. (2020). Segregation of Lolium perenne into a subpopulation with high infection by endophyte Epichloë festucae var. lolii results in improved agronomic performance. Plant and Soil, 446, 595–612. https://doi.org/10.1007/s11104-019-04370-w

[9] Fabien, M., Nathalle, V., Adnan, H., Alain, C., & Huguette, S. (2001). Endophytic Neotyphodium lolii induced tolerance to Zn stress in Lolium perenne. Plant Physiology, 113(4), 557–563. https://doi.org/10.1034/j.1399-3054.2001.1130415.x

[10] Gong, Y., Zhao, D., & Wang, Q. (2018). An overview of field-scale studies on remediation of soil contaminated with heavy metals and metalloids: Technical progress over the last decade. Water Research, 147, 440–460. https://doi.org/10.1016/j.watres.2018.10.024

[11] Harrington, J. T., Mexal, J. G., & Fisher, J. T. (1994). Volume displacement provides a quick and accurate way to quantify new root production. Tree Planter's Notes, 45(4), 121–124.

[12] Hasanuzzaman, M., Bhuyan, M. H. M., Zulfiqar, F., Raza, A., Mohsin, S., Mahmud, J., Fujita, M., & Fotopoulos, V. (2020). Reactive oxygen species and antioxidant defense in plants under abiotic stress: Revisiting the crucial role of a universal defense regulator. Antioxidants, 9(8), 681. https://doi.org/10.3390/antiox9080681

[13] Jiang, Y., & Huang, B. (2001). Drought and heat stress injury to two cool season turfgrasses in relation to antioxidant metabolism and lipid peroxidation. Crop Science, 41(2), 436–442. https://doi.org/10.2135/cropsci2001.412436x

[14] Johnson, L. J., de Bonth, A. C. M., Briggs, L. R., Caradus, J. R., Finch, S. C., Fleetwood, D. J., Fletcher, L. R., Hume, D. E., Johnson, R. D., Popay, A. J., Tapper, B. A., Simpson, W. R., Voisey, C. R., & Card, S. D. (2013). The exploitation of epichloae endophytes for agricultural benefit. Fungal Diversity, 60(1), 171–188. https://doi.org/10.1007/s13225-013-0239-4

[15] Lanaras, T., Moustakas, M., Symeonidis, L., Diamantoglou, S., & Karataglis, S. (1993). Plant metal content, growth responses and some photosynthetic measurements on field-cultivated wheat growing on ore bodies enriched in Cu. Physiologia Plantarum, 88(2), 307–314. https://doi.org/10.1111/j.1399-3054.1993.tb05504.x

[16] Lee, S. H., Choi, J. H., Kim, W. S., Han, T. H., Park, Y. S., & Gemma, H. (2006). Effect of soil water stress on the development of stone cells in pear (Pyrus pyrifolia cv. ‘Niitaka’) flesh. Scientia Horticulturae, 110, 247–253. https://doi.org/10.1016/j.scienta.2006.07.012

[17] Leuchtmann, A., Bacon, C. W., Schardl, C. L., White, J. F., & Tadych, M. (2014). Nomenclatural realignment of Neotyphodium species with genus Epichloë. Mycologia, 106(2), 202–215. https://doi.org/10.3852/13-251

[18] Li, C., Li, X., Ren, A. Z., & Gao, Y. B. (2013). Effect of endophyte infection on Zn resistance of Achnatherum sibiricum. Acta Scientiarum Naturalium University Nankaiensis, 46(4), 29–35.

[19] Li, H. Q., Wang, J. J., Zhang, G. M., Lin, W. H., & Tian, P. (2016). Effects of fungal endophytes on the growth of perennial ryegrass under drought condition. Pratacultural Science, 33(4), 599–607.

[20] Ma, M., Christensen, M. J., & Nan, Z. (2015). Effects of the endophyte Epichloë festucae var. lolii of perennial ryegrass (Lolium perenne) on indicators of oxidative stress from pathogenic fungi during seed germination and seedling growth. European Journal of Plant Pathology, 141(3), 571–583. https://doi.org/10.1007/s10658-014-0563-x

[21] Malinowski, D. P., & Belesky, D. P. (1999). Tall fescue aluminum tolerance is affected by Neotyphodium coenophialum endophyte. Journal of Plant Nutrition, 22(8), 1335–1349. https://doi.org/10.1080/01904169909365716

[22] Malinowski, D. P., & Belesky, D. P. (2019). Epichloë (formerly Neotyphodium) fungal endophytes increase adaptation of cool-season perennial grasses to environmental stresses. Acta Agrobotanica, 72(2), 1767. https://doi.org/10.5586/aa.1767

[23] Masindi, V., & Muedi, K. L. (2018). Environmental contamination by heavy metals. In H. E. M. Saleh & R. F. Aglan (Eds.), Heavy Metals (pp. 115–132). London: IntechOpen. https://doi.org/10.5772/intechopen.76082

[24] Monnet, F., Vaillant, N., Hitmi, A., Coudret, A., & Sallanon, H. (2001). Endophytic Neotyphodium lolii induced tolerance to Zn stress in Lolium perenne. Physiologia Plantarum, 113(4), 557–563. https://doi.org/10.1034/j.1399-3054.2001.1130415.x.

[25] Nagajyoti, P. C., Lee, K. D., & Sreekanth, T. V. M. (2010). Heavy metals, occurrence and toxicity for plants: A review. Environmental Chemistry Letters, 8(3), 199–216. https://doi.org/10.1007/s10311-010-0297-8

[26] Nan, Z. B. (1996). Incidence and distribution of endophytic fungi in seeds and plants of some native and introduced grasses in China. Acta Prataculturae Sinica, 5, 13–17.

[27] Ren, A., Gao, Y., Zhang, L., & Xie, F. (2006). Effects of cadmium on growth parameters of endophyte-infected endophyte-free ryegrass. Journal of Plant Nutrition and Soil Science, 169(6), 857–860. https://doi.org/10.1002/jpln.200520543

[28] Schardl, C. L., Florea, S., Pan, J., Nagabhyru, P., Bec, S., & Calie, P. J. (2013). The epichloae: Alkaloid diversity and roles in symbiosis with grasses. Current Opinion in Plant Biology, 16(4), 480–488. https://doi.org/10.1016/j.pbi.2013.06.012

[29] Shi, Q., Simpson, W. R., Li, Y., Xu, C., De, K., & Li, X. (2024). Epichloë bromicola enhances Elymus dahucirus plant growth and antioxidant capacity under cadmium stress. Agronomy, 14(2), 365. https://doi.org/10.3390/agronomy14020365

[30] Soleimani, M., Hajabbasi, M. A., Afyuni, M., Mirlohi, A., Borggaard, O. K., & Holm, P. E. (2010). Effect of endophytic fungi on cadmium tolerance and bioaccumulation by Festuca arundinacea and Festuca pratensis. International Journal of Phytoremediation, 12(6), 535–549. https://doi.org/10.1080/15226510903353187

[31] Tian, P., Nan, Z., Li, C., & Spangenberg, G. (2008). Effect of the endophyte Neotyphodium lolii on susceptibility and host physiological response of perennial ryegrass to fungal pathogens. European Journal of Plant Pathology, 122(4), 593–602. https://doi.org/10.1007/s10658-008-9329-7

[32] Tian, P., Wang, M., Luo, Y., Wang, X., & Xu, W. (2022). Growth performance of different Epichloë sinensis strains on media with different additives. Grassland Research, 1(3), 187–196. https://doi.org/10.1002/glr2.12029

[33] Vivek, P., Prabhakaran, S., & Shankar, S. R. (2013). Assessment of nutritional value in selected edible greens based on the chlorophyll content in leaves. Research in Plant Biology, 3(5), 45–49.

[34] Wang, M., Tian, P., Gao, M., & Li, M. (2021). The promotion of Festuca sinensis under heavy metal treatment mediated by Epichloë endophyte. Agronomy, 11(10), 2049. https://doi.org/10.3390/agronomy11102049

[35] Zamani, N., Sabzalian, M. R., Khoshgoftarmanesh, A., & Afyuni, M. (2014). Neotyphodium endophyte changes phytoextraction of zinc in Festuca arundinacea and Lolium perenne. International Journal of Phytoremediation, 17(5), 456–463. https://doi.org/10.1080/15226514.2014.922919

[36] Zaurov, D. E., Bonos, S., Murphy, J. A., Richardson, M., & Belanger, F. C. (2001). Endophyte infection can contribute to aluminum tolerance in fine fescues. Crop Science, 41(6), 1981–1984. https://doi.org/10.2135/cropsci2001.1981

[37] Zhang, X., Li, C., & Nan, Z. (2010). Effects of cadmium stress on growth and anti-oxidative systems in Achnatherum inebrians, symbiotic with Neotyphodium gansuens. Journal of Hazardous Materials, 175(1–3), 703–709. https://doi.org/10.1016/j.jhazmat.2009.10.066

[38] Zhang, X., Li, C., & Nan, Z. (2012). Effects of cadmium stress on seed germination and seedling growth of Elymus dahuricus infected with the Neotyphodium endophyte. Science China Life Sciences, 55(9), 793–799. https://doi.org/10.1007/s11427-012-4359-y

[39] Zhao, D. D. (2008). Studies on growth and resistance of Festuca arundinacea under the stress of Cd²⁺ and Cd²⁺-Zn²⁺ (Master dissertation, Sichuan Normal University.

[40] Żurek, G., Wiewióra, B., Rybka, K., & Prokopiuk, K. (2022). Different response of perennial ryegrass—Epichloë endophyte symbiota to the elevated concentration of heavy metals in soil. Journal of Applied Genetics, 63(1), 47–59. https://doi.org/10.1007/s13353-021-00661-0

RIGHTS & PERMISSIONS

2025 The Author(s). Grassland Research published by John Wiley & Sons Australia, Ltd on behalf of Chinese Grassland Society and Lanzhou University.