Rice diterpenoid phytoalexins (DPs) are secondary metabolites with a well known role in resistance to foliar pathogens. As DPs are also known to be produced and exuded by rice roots, we hypothesised that they might play an important role in plant-nematode interactions, and particularly in defence against phytoparasitic nematodes. We used transcriptome analysis on rice roots to analyse the effect of infection by the root-knot nematode Meloidogyne graminicola or treatment with resistance-inducing chemical stimuli on DP biosynthesis genes, and assessed the susceptibility of mutant rice lines impaired in DP biosynthesis to M. graminicola. Moreover, we grew these mutants and their wild-type in field soil and used metabarcoding to assess the effect of impairment in DP biosynthesis on rhizosphere and root nematode communities. We show that M. graminicola suppresses DP biosynthesis genes early in its invasion process and, conversely, that resistance-inducing stimuli transiently induce the biosynthesis of DPs. Moreover, we show that loss of DPs increases susceptibility to M. graminicola. Metabarcoding on wild-type and DP-deficient plants grown in field soil reveals that DPs significantly alter the composition of rhizosphere and root nematode communities. Diterpenoid phytoalexins are important players in basal and inducible defence against nematode pathogens of rice and help shape rice-associated nematode communities.
Ahuja I, Kissen R, Bones AM. 2012. Phytoalexins in defense against pathogens. Trends in Plant Science 17: 73-90.
Akagi A, Fukushima S, Okada K, Jiang CJ, Yoshida R, Nakayama A, Shimono M, Sugano S, Yamane H, Takatsuji H. 2014. WRKY45-dependent priming of diterpenoid phytoalexin biosynthesis in rice and the role of cytokinin in triggering the reaction. Plant Molecular Biology 86: 171-183.
Bolyen E, Rideout JR, Dillon MR, Bokulich NA, Abnet CC, Al-Ghalith GA, Alexander H, Alm EJ, Arumugam M, Asnicar F et al. 2019. Reproducible, interactive, scalable and extensible microbiome data science using Qiime 2. Nature Biotechnology 37: 852-857.
Bongers T. 1990. The maturity index: an ecological measure of environmental disturbance based on nematode species composition. Oecologia 83: 14-19.
Bridge J, Page SLJ. 1980. Estimation of root-knot nematode infestation levels on roots using a rating chart. Tropical Pest Management 26: 296-298.
Chavan SN, De Kesel J, Desmedt W, Degroote E, Singh RR, Nguyen G, Demeestere K, De Meyer T, Kyndt T. 2022. Dehydroascorbate induces plant resistance in rice against root-knot nematode Meloidogyne graminicola. Molecular Plant Pathology, in press.
Cho MH, Lee SW. 2015. Phenolic phytoalexins in rice: biological functions and biosynthesis. International Journal of Molecular Sciences 16: 29120-29133.
De Kesel J, Conrath U, Flors V, Luna E, Mageroy MH, Mauch-Mani B, Pastor V, Pozo MJ, Pieterse CMJ, Ton J et al. 2021. The induced resistance lexicon: do’s and don’ts. Trends in Plant Science 26: 685-691.
Desmedt W, Jonckheere W, Nguyen VH, Ameye M, De Zutter N, De Kock K, Debode J, Van Leeuwen T, Audenaert K, Vanholme B et al. 2021a. The phenylpropanoid pathway inhibitor piperonylic acid induces broad-spectrum pest and disease resistance in plants. Plant, Cell & Environment 44: 3122-3139.
Desmedt W, Mangelinckx S, Kyndt T, Vanholme B. 2020. A phytochemical perspective on plant defense against nematodes. Frontiers in Plant Science 11: 1765.
Desmedt W, Vanholme B, Kyndt T. 2021b. Plant defense priming in the field: a review. In: Maienfisch P, Mangelinckx S, eds. Recent highlights in the discovery and optimization of crop protection products. London, UK: Academic Press, 87-124.
Fanelli E, Cotroneo A, Carisio L, Troccoli A, Grosso S, Boero C, Capriglia F, De Luca F. 2017. Detection and molecular characterization of the rice root-knot nematode Meloidogyne graminicola in Italy. European Journal of Plant Pathology 149: 467-476.
García-Sánchez M, Souche M, Trives-Segura C, Plassard C. 2021. The grazing activity of Acrobeloides sp. drives phytate mineralisation within its trophic relationship with bacteria. Journal of Nematology 53: 2021-2042.
Ghaemi R, Pourjam E, Safaie N, Verstraeten B, Mahmoudi SB, Mehrabi R, De Meyer T, Kyndt T. 2020. Molecular insights into the compatible and incompatible interactions between sugar beet and the beet cyst nematode. BMC Plant Biology 20: 483.
Harborne JB. 1999. The comparative biochemistry of phytoalexin induction in plants. Biochemical Systematics and Ecology 27: 335-367.
Ji H, Kyndt T, He W, Vanholme B, Gheysen G. 2015. Β-aminobutyric acid-induced resistance against root-knot nematodes in rice is based on increased basal defence. Molecular Plant-Microbe Interactions 28: 519-533.
Kato-Noguchi H, Peters RJ. 2013. The role of momilactones in rice allelopathy. Journal of Chemical Ecology 39: 175-185.
Khan Z, Kim YH. 2007. A review on the role of predatory soil nematodes in the biological control of plant parasitic nematodes. Applied Soil Ecology 35: 370-379.
Kim SJ, Park HR, Park E, Lee SC. 2007. Cytotoxic and antitumor activity of momilactone B from rice hulls. Journal of Agricultural and Food Chemistry 55: 1702-1706.
Kim T, Kim J, Park JK. 2017. Acrobeloides varius sp. n. (Rhabditida: cephalobidae) from South Korea. Nematology 19: 489-496.
Kyndt T, Denil S, Haegeman A, Trooskens G, Bauters L, Van Criekinge W, De Meyer T, Gheysen G. 2012a. Transcriptional reprogramming by root knot and migratory nematode infection in rice. New Phytologist 196: 887-900.
Kyndt T, Nahar K, Haegeman A, De Vleesschauwer D, Höfte M, Gheysen G. 2012b. Comparing systemic defence-related gene expression changes upon migratory and sedentary nematode attack in rice. Plant Biology 14: 73-82.
Liu T, Yu L, Xu J, Yan X, Li H, Whalen JK, Hu F. 2017. Bacterial traits and quality contribute to the diet choice and survival of bacterial-feeding nematodes. Soil Biology and Biochemistry 115: 467-474.
Love MI, Huber W, Anders S. 2014. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2. Genome Biology 15: 550.
Lu X, Zhang J, Brown B, Li R, Rodríguez-Romero J, Berasategui A, Liu BO, Xu M, Luo D, Pan Zet al. 2018. Inferring roles in defense from metabolic allocation of rice diterpenoids. Plant Cell 30: 1119-1131.
Mantelin S, Bellafiore S, Kyndt T. 2017. Meloidogyne graminicola: a major threat to rice agriculture. Molecular Plant Pathology 18: 3-15.
Mauch-Mani B, Baccelli I, Luna E, Flors V. 2017. Defense priming: an adaptive part of induced resistance. Annual Review of Plant Biology 68: 485-512.
Mikami M, Toki S, Endo M. 2015. Comparison of CRISPR/Cas9 expression constructs for efficient targeted mutagenesis in rice. Plant Molecular Biology 88: 561-572.
Nahar K, Kyndt T, De Vleesschauwer D, Höfte M, Gheysen G. 2011. The jasmonate pathway is a key player in systemically induced defense against root knot nematodes in rice. Plant Physiology 157: 305-316.
Nguyen SV, Nguyen PTK, Araki M, Perry RN, Ba Tran L, Minh Chau K, Min YY, Toyota K. 2020. Effects of cropping systems and soil amendments on nematode community and its relationship with soil physicochemical properties in a paddy rice field in the Vietnamese Mekong Delta. Applied Soil Ecology 156: 103683.
Oksanen J, Blanchet G, Friendly M, Kindt R, Legendre P, McGlinn D, Minchin PR, O’Hara RB, Simpson GL, Solymos P et al. 2020. vegan: community ecology package. R package v.2.5-7. [WWW document] URL https://CRAN.R-project.org/package=vegan [accessed 7 December 2021].
Park C, Jeong NY, Kim GY, Han MH, Chung IM, Kim WJ, Yoo YH, Choi YH. 2014. Momilactone B induces apoptosis and G1 arrest of the cell cycle in human monocytic leukemia U937 cells through downregulation of pRB phosphorylation and induction of the cyclin-dependent kinase inhibitor p21Waf1/Cip1. Oncology Reports 31: 1653-1660.
Petitot AS, Kyndt T, Haidar R, Dereeper A, Collin M, De Almeida EJ, Gheysen G, Fernandez D. 2017. Transcriptomic and histological responses of African rice (Oryza glaberrima) to Meloidogyne graminicola provide new insights into root-knot nematode resistance in monocots. Annals of Botany 119: 885-899.
Piñol J, Mir G, Gomez-Polo P, Agustí N. 2015. Universal and blocking primer mismatches limit the use of high-throughput DNA sequencing for the quantitative metabarcoding of arthropods. Molecular Ecology Resources 15: 819-830.
Raudvere U, Kolberg L, Kuzmin I, Arak T, Adler P, Peterson H, Vilo J. 2019. g:Profiler: a web server for functional enrichment analysis and conversions of gene lists (2019 update). Nucleic Acids Research 47: W191-W198.
Reversat G, Boyer J, Pando-Bahuon A, Sannier C. 1999. Use of a mixture of sand and water-absorbent synthetic polymer as substrate for the xenic culturing of plant-parasitic nematodes in the laboratory. Nematology 1: 209-212.
Riemann M, Haga K, Shimizu T, Okada K, Ando S, Mochizuki S, Nishizawa Y, Yamanouchi U, Nick P, Yano M et al. 2013. Identification of rice Allene Oxide Cyclase mutants and the function of jasmonate for defence against Magnaporthe oryzae. The Plant Journal 74: 226-238.
Rognes T, Flouri T, Nichols B, Quince C, Mahé F. 2016. Vsearch: a versatile open source tool for metagenomics. PeerJ 4. doi: 10.7717/PEERJ.2584/FIG-7.
Schmelz EA, Huffaker A, Sims JW, Christensen SA, Lu X, Okada K, Peters RJ. 2014. Biosynthesis, elicitation and roles of monocot terpenoid phytoalexins. The Plant Journal 79: 659-678.
Shimizu T, Miyamoto K, Minami E, Nishizawa Y, Iino M, Nojiri H, Yamane H, Okada K. 2013. OsJAR1 contributes mainly to biosynthesis of the stress-induced jasmonoyl-isoleucine involved in defense responses in rice. Bioscience, Biotechnology, and Biochemistry 77: 1556-1564.
Shimizu T, Nakano T, Takamizawa D, Desaki Y, Ishii-Minami N, Nishizawa Y, Minami E, Okada K, Yamane H, Kaku H et al. 2010. Two LysM receptor molecules, CEBiP and OsCERK1, cooperatively regulate chitin elicitor signaling in rice. The Plant Journal 64: 204-214.
Sikder MM, Vestergård M. 2020. Impacts of root metabolites on soil nematodes. Frontiers in Plant Science 10: 1792.
Sikder MM, Vestergård M, Kyndt T, Fomsgaard IS, Kudjordjie EN, Nicolaisen M. 2021. Benzoxazinoids selectively affect maize root-associated nematode taxa. Journal of Experimental Botany 72: 3835-3845.
Sikder MM, Vestergård M, Sapkota R, Kyndt T, Nicolaisen M. 2020. Evaluation of metabarcoding primers for analysis of soil nematode communities. Diversity 12: 388.
Singh RR, Verstraeten B, Siddique S, Tegene AM, Tenhaken R, Frei M, Haeck A, Demeestere K, Pokhare S, Gheysen G et al. 2020. Ascorbate oxidation activates systemic defence against root-knot nematode Meloidogyne graminicola in rice. Journal of Experimental Botany 71: 4271-4284.
Smith CJ. 1996. Tansley review no. 86 Accumulation of phytoalexins: defence mechanism and stimulus response system. New Phytologist 132: 1-45.
Toki S, Hara N, Ono K, Onodera H, Tagiri A, Oka S, Tanaka H. 2006. Early infection of scutellum tissue with Agrobacterium allows high-speed transformation of rice. The Plant Journal 47: 969-976.
Toyomasu T, Kagahara T, Okada K, Koga J, Hasegawa M, Mitsuhashi W, Sassa T, Yamane H. 2008. Diterpene phytoalexins are biosynthesized in and exuded from the roots of rice seedlings. Bioscience, Biotechnology, and Biochemistry 72: 562-567.
Toyomasu T, Usui M, Sugawara C, Otomo K, Hirose Y, Miyao A, Hirochika H, Okada K, Shimizu T, Koga J et al. 2014. Reverse-genetic approach to verify physiological roles of rice phytoalexins: characterization of a knockdown mutant of OsCPS4 phytoalexin biosynthetic gene in rice. Physiologia Plantarum 150: 55-62.
Verbeek REM, Van Buyten E, Alam MZ, De Vleesschauwer D, Van Bockhaven J, Asano T, Kikuchi S, Haeck A, Demeestere K, Gheysen G et al. 2019. Jasmonate-induced defense mechanisms in the belowground antagonistic interaction between Pythium arrhenomanes and Meloidogyne graminicola in rice. Frontiers in Plant Science 10: 1515.
Xu M, Galhano R, Wiemann P, Bueno E, Tiernan M, Wu W, Chung IM, Gershenzon J, Tudzynski B, Sesma A et al. 2012. Genetic evidence for natural product-mediated plant-plant allelopathy in rice (Oryza sativa). New Phytologist 193: 570-575.
Yamamura C, Mizutani E, Okada K, Nakagawa H, Fukushima S, Tanaka A, Maeda S, Kamakura T, Yamane H, Takatsuji H et al. 2015. Diterpenoid phytoalexin factor, a bHLH transcription factor, plays a central role in the biosynthesis of diterpenoid phytoalexins in rice. The Plant Journal 84: 1100-1113.
Yamane H. 2013. Biosynthesis of phytoalexins and regulatory mechanisms of it in rice. Bioscience, Biotechnology, and Biochemistry 77: 1141-1148.
Yeates GW, Bongers T, De Goede RGM, Freckman DW, Georgieva SS. 1993. Feeding habits in soil nematode families and genera - an outline for soil ecologists. Journal of Nematology 25: 315-331.
Yokotani N, Sato Y, Tanabe S, Chujo T, Shimizu T, Okada K, Yamane H, Shimono M, Sugano S, Takatsuji H et al. 2013. WRKY76 is a rice transcriptional repressor playing opposite roles in blast disease resistance and cold stress tolerance. Journal of Experimental Botany 64: 5085-5097.
Yoshida Y, Miyamoto K, Yamane H, Nishizawa Y, Minami E, Nojiri H, Okada K. 2017. OsTGAP1 is responsible for JA-inducible diterpenoid phytoalexin biosynthesis in rice roots with biological impacts on allelopathic interaction. Physiologia Plantarum 161: 532-544.
Zhang J, Li R, Xu M, Hoffmann RI, Zhang Y, Liu B, Zhang M, Yang B, Li Z, Peters RJ. 2021. A (conditional) role for labdane-related diterpenoid natural products in rice stomatal closure. New Phytologist 230: 698-709.