Abstracts
The biosynthesis of branched-chain amino acids (BCAAs) is conserved in fungi and plants, but not in animals. The Leu1 gene encodes isopropylmalate isomerase that catalyzes the conversion of α-isopropylmalate into β-isopropylmalate in the second step of leucine biosynthesis in yeast. Here, we identified and characterized the functions of MoLeu1, an ortholog of yeast Leu1 in the rice blast fungus Magnaporthe oryzae. The transcriptional level of MoLEU1 was increased during conidiation and in infectious stages. Cellular localization analysis indicated that MoLeu1 localizes to the cytoplasm at all stages of fungal development. Targeted gene deletion of MoLEU1 led to leucine auxotrophy, and phenotypic analysis of the generated ∆Moleu1 strain revealed that MoLeu1-mediated leucine biosynthesis was required for vegetative growth, asexual development, and pathogenesis of M. oryzae. We further observed that invasive hyphae produced by the ∆Moleu1 strain were mainly limited to the primary infected host cells. The application of exogenous leucine fully restored vegetative growth and partially restored conidiation as well as pathogenicity defects in the ∆Moleu1 strain. In summary, our results suggested that MoLeu1-mediated leucine biosynthesis crucially promotes vegetative growth, conidiogenesis, and pathogenicity of M. oryzae. This study helps unveil the regulatory mechanisms that are essential for infection-related morphogenesis and pathogenicity of the rice blast fungus.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Binder S (2010) Branched-chain amino acid metabolism in Arabidopsis thaliana. Arabidopsis Book 8:e0137. https://doi.org/10.1199/tab.0137
Bruno KS, Tenjo F, Li L, Hamer JE, Xu JR (2004) Cellular localization and role of kinase activity of PMK1 in Magnaporthe grisea. Eukaryot Cell 3(6):1525–1532. https://doi.org/10.1128/EC.3.6.1525-1532.2004
Chen Y, Zuo RF, Zhu Q, Sun Y, Li MY, Dong YH, Ru YY, Zhang HF, Zheng XB, Zhang ZG (2014) MoLys2 is necessary for growth, conidiogenesis, lysine biosynthesis, and pathogenicity in Magnaporthe oryzae. Fungal Genet Biol 67:51–57. https://doi.org/10.1016/j.fgb.2014.04.001
Do E, Hu G, Caza M, Oliveira D, Kronstad JW, Jung WH (2015) Leu1 plays a role in iron metabolism and is required for virulence in Cryptococcus neoformans. Fungal Genet Biol 75:11–19. https://doi.org/10.1016/j.fgb.2014.12.006
Du Y, Zhang H, Hong L, Wang J, Zheng X, Zhang Z (2013) Acetolactate synthases MoIlv2 and MoIlv6 are required for infection-related morphogenesis in Magnaporthe oryzae. Mol Plant Pathol 14(9):870–884. https://doi.org/10.1111/mpp.12053
Ebbole DJ (2007) Magnaporthe as a model for understanding host-pathogen interactions. Annu Rev Phytopathol 45(1):437–456. https://doi.org/10.1146/annurev.phyto.45.062806.094346
Foster AJ, Ryder LS, Kershaw MJ, Talbot NJ (2017) The role of glycerol in the pathogenic lifestyle of the rice blast fungus Magnaporthe oryzae. Environ Microbiol 19(3):1008–1016. https://doi.org/10.1111/1462-2920.13688
Guo M, Gao F, Zhu X, Nie X, Pan Y, Gao Z (2015) MoGrr1, a novel F-box protein, is involved in conidiogenesis and cell wall integrity and is critical for the full virulence of Magnaporthe oryzae. Appl Microbiol Biotechnol 99(19):8075–8088. https://doi.org/10.1007/s00253-015-6820-x
Hamer L, Adachi K, Dezwaan T, Lo S, Montenegro-Chamorro MV, Frank S, Darveaux B, Mahanty S, Heiniger R, Skalchunes A, Pan H, Tarpey R, Shuster J, Tanzer MM (2004) Methods for the identification of inhibitors of 3-isopropylmalate dehydratase as antibiotics. United States Patent 6733963
Howard RJ, Ferrari MA, Roach DH, Money NP (1991) Penetration of hard substrates by a fungus employing enormous turgor pressures. Proc Natl Acad Sci U S A 88(24):11281–11284
Hsu YP, Schimmel P (1984) Yeast LEU1. Repression of mRNA levels by leucine and relationship of 5′-noncoding region to that of LEU2. J Biol Chem 259(6):3714–3719
Kimball SR, Jefferson LS (2006) Signaling pathways and molecular mechanisms through which branched-chain amino acids mediate translational control of protein synthesis. J Nutr 136(1 Suppl):227S–231S. https://doi.org/10.1093/jn/136.1.227S
Kohlhaw GB (2003) Leucine biosynthesis in fungi: entering metabolism through the back door. Microbiol Mol Biol Rev 67(1):1–15. https://doi.org/10.1128/MMBR.67.1.1–15.2003
Kong LA, Li GT, Liu Y, Liu MG, Zhang SJ, Yang J, Zhou XY, Peng YL, Xu JR (2013) Differences between appressoria formed by germ tubes and appressorium-like structures developed by hyphal tips in Magnaporthe oryzae. Fungal Genet Biol 56:33–41. https://doi.org/10.1016/j.fgb.2013.03.006
Liu WD, **e SY, Zhao XH, Chen X, Zheng WH, Lu GD, Xu JR, Wang ZH (2010) A homeobox gene is essential for conidiogenesis of the rice blast fungus Magnaporthe oryzae. Mol Plant-Microbe Interact 23(4):366–375. https://doi.org/10.1094/Mpmi-23-4-0366
Liu X, Han Q, Wang J, Wang X, Xu J, Shi J (2016) Two FgLEU2 genes with different roles in leucine biosynthesis and infection-related morphogenesis in Fusarium graminearum. PLoS One 11(11):e0165927. https://doi.org/10.1371/journal.pone.0165927
Livak KJ, Schmittgen TD (2001) Analysis of relative gene expression data using real-time quantitative PCR and the 2-ΔΔC T method. Methods 25(4):402–408. https://doi.org/10.1006/meth.2001.1262
McCourt JA, Duggleby RG (2006) Acetohydroxyacid synthase and its role in the biosynthetic pathway for branched-chain amino acids. Amino Acids 31(2):173–210. https://doi.org/10.1007/s00726-005-0297-3
Monirujjaman M, Ferdouse A (2014) Metabolic and physiological roles of branched-chain amino acids. Adv Mol Biol 2014:1–6. https://doi.org/10.1155/2014/364976
Norvienyeku J, Zhong Z, Lin L, Dang X, Chen M, Lin X, Zhang H, Anjago WM, Abdul W, Wang Z (2017) Methylmalonate-semialdehyde dehydrogenase mediated metabolite homeostasis essentially regulate conidiation, polarized germination and pathogenesis in Magnaporthe oryzae. Environ Microbiol 19(10):4256–4277. https://doi.org/10.1111/1462-2920.13888
Radford JA, Lieberman BA, Brison DR, Smith AR, Critchlow JD, Russell SA, Watson AJ, Clayton JA, Harris M, Gosden RG, Shalet SM (2001) Orthotopic reimplantation of cryopreserved ovarian cortical strips after high-dose chemotherapy for Hodgkin’s lymphoma. Lancet 357(9263):1172–1175
Ryan ED, Tracy JW, Kohlhaw GB (1973) Subcellular localization of the leucine biosynthetic enzymes in yeast. J Bacteriol 116(1):222–225
Solomon PS, Oliver RP (2001) The nitrogen content of the tomato leaf apoplast increases during infection by Cladosporium fulvum. Planta 213(2):241–249. https://doi.org/10.1007/s004250000500
Solomon PS, Tan KC, Oliver RP (2003) The nutrient supply of pathogenic fungi; a fertile field for study. Mol Plant Pathol 4(3):203–210. https://doi.org/10.1046/j.1364-3703.2003.00161.x
Sweigard JA, Chumley FG, Valent B (1992) Disruption of a Magnaporthe grisea cutinase gene. Mol Gen Genet 232(2):183–190
Talbot NJ (2003) On the trail of a cereal killer: exploring the biology of Magnaporthe grisea. Annu Rev Microbiol 57:177–202. https://doi.org/10.1146/annurev.micro.57.030502.090957
Talbot NJ, Ebbole DJ, Hamer JE (1993) Identification and characterization of MPG1, a gene involved in pathogenicity from the rice blast fungus Magnaporthe grisea. Plant Cell 5(11):1575–1590. https://doi.org/10.1105/tpc.5.11.1575
Tang QY, Zhang CX (2013) Data Processing System (DPS) software with experimental design, statistical analysis and data mining developed for use in entomological research. Insect Sci 20(2):254–260. https://doi.org/10.1111/j.1744-7917.2012.01519.x
Tang W, Ru Y, Hong L, Zhu Q, Zuo R, Guo X, Wang J, Zhang H, Zheng X, Wang P, Zhang Z (2015) System-wide characterization of bZIP transcription factor proteins involved in infection-related morphogenesis of Magnaporthe oryzae. Environ Microbiol 17(4):1377–1396. https://doi.org/10.1111/1462-2920.12618
Wilson RA, Fernandez J, Quispe CF, Gradnigo J, Seng A, Moriyama E, Wright JD (2012) Towards defining nutrient conditions encountered by the rice blast fungus during host infection. PLoS One 7(10):e47392. https://doi.org/10.1371/journal.pone.0047392
Wilson RA, Talbot NJ (2009) Under pressure: investigating the biology of plant infection by Magnaporthe oryzae. Nat Rev Microbiol 7(3):185–195. https://doi.org/10.1038/nrmicro2032
Yoshizawa F (2004) Regulation of protein synthesis by branched-chain amino acids in vivo. Biochem Biophys Res Commun 313(2):417–422
Yu JH, Hamari Z, Han KH, Seo JA, Reyes-Dominguez Y, Scazzocchio C (2004) Double-joint PCR: a PCR-based molecular tool for gene manipulations in filamentous fungi. Fungal Genet Biol 41(11):973–981. https://doi.org/10.1016/j.fgb.2004.08.001
Zhang H, Liu K, Zhang X, Tang W, Wang J, Guo M, Zhao Q, Zheng X, Wang P, Zhang Z (2011a) Two phosphodiesterase genes, PDEL and PDEH, regulate development and pathogenicity by modulating intracellular cyclic AMP levels in Magnaporthe oryzae. PLoS One 6(2):e17241. https://doi.org/10.1371/journal.pone.0017241
Zhang H, Tang W, Liu K, Huang Q, Zhang X, Yan X, Chen Y, Wang J, Qi Z, Wang Z, Zheng X, Wang P, Zhang Z (2011b) Eight RGS and RGS-like proteins orchestrate growth, differentiation, and pathogenicity of Magnaporthe oryzae. PLoS Pathog 7(12):e1002450. https://doi.org/10.1371/journal.ppat.1002450
Zhang Y, Shi H, Liang S, Ning G, Xu N, Lu J, Liu X, Lin F (2015) MoARG1, MoARG5,6 and MoARG7 involved in arginine biosynthesis are essential for growth, conidiogenesis, sexual reproduction, and pathogenicity in Magnaporthe oryzae. Microbiol Res 180:11–22. https://doi.org/10.1016/j.micres.2015.07.002
Zhao X, Xue C, Kim Y, Xu JR (2004) A ligation-PCR approach for generating gene replacement constructs in Magnaporthe grisea. Fungal Genet Newsl 51(1):17–18. https://doi.org/10.4148/1941-4765.1137
Funding
This research was supported by the Natural Science Foundation of China (31601584), Natural Science Foundation of Fujian Province (2016J05070), Science Fund for Distinguished Young Scholars of Fujian Agriculture and Forestry University to W. T. (KXJQ17020), and China Scholarship Council.
Author information
Authors and Affiliations
Corresponding authors
Ethics declarations
This article does not contain any studies with human participants or animals performed by any of the authors.
Conflict of interest
The authors declare that they have no conflict of interest.
Electronic supplementary material
ESM 1
(PDF 848 kb)
Rights and permissions
About this article
Cite this article
Tang, W., Jiang, H., Zheng, Q. et al. Isopropylmalate isomerase MoLeu1 orchestrates leucine biosynthesis, fungal development, and pathogenicity in Magnaporthe oryzae. Appl Microbiol Biotechnol 103, 327–337 (2019). https://doi.org/10.1007/s00253-018-9456-9
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00253-018-9456-9