Degradation of glyoxalase I in Brassica napus stigma leads to self-incompatibility response


Self-incompatibility (rejection of ‘self’-pollen) is a reproductive barrier that allows hermaphroditic flowering plants to prevent inbreeding, to promote outcrossing and hybrid vigour. The self-incompatibility response in Brassica involves allele-specific interaction between the pollen small cysteine-rich, secreted protein ligand (SCR/SP11) and the stigmatic S-receptor kinase (SRK), which leads to the activation of the E3 ubiquitin ligase ARC1 (Armadillo repeat-containing 1), resulting in proteasomal degradation of compatibility factors needed for successful pollination. Despite this, targets of ARC1 and the intracellular signalling network that is regulated by these targets, have remained elusive. Here we show that glyoxalase I (GLO1), an enzyme that is required for the detoxification of methylglyoxal (MG, a cytotoxic by-product of glycolysis), is a stigmatic compatibility factor required for pollination to occur and is targeted by the self-incompatibility system. Suppression of GLO1 was sufficient to reduce compatibility, and overexpression of GLO1 in self-incompatible Brassica napus stigmas resulted in partial breakdown of the self-incompatibility response. ARC1-mediated destruction of GLO1 after self-pollination results in increased MG levels and a concomitant increase in MG-modified proteins (including GLO1), which are efficiently targeted for destruction in the papillary cells, leading to pollen rejection. Our findings demonstrate the elegant nature of plants to use a metabolic by-product to regulate the self-incompatibility response.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: GLO1 is required for compatible pollination.
Figure 2: GLO1 is a target of ARC1 during self-incompatibility.
Figure 3: GLO1 overexpression in self-incompatible W1 stigmas leads to partial breakdown of the self-incompatibility response.
Figure 4: GLO1 is modified by MG in vivo and MG-modified GLO1 is efficiently ubiquitinated by ARC1.
Figure 5


  1. 1

    Takayama, S. et al. The pollen determinant of self-incompatibility in Brassica campestris. Proc. Natl Acad. Sci. USA 97, 1920–1925 (2000).

    CAS  Article  Google Scholar 

  2. 2

    Kachroo, A., Schopfer, C. R., Nasrallah, M. E. & Nasrallah, J. B. Allele-specific receptor-ligand interactions in Brassica self-incompatibility. Science 293, 1824–1826 (2001).

    CAS  Article  Google Scholar 

  3. 3

    Shimosato, H. et al. Characterization of the SP11/SCR high-affinity binding site involved in self/nonself recognition in Brassica self-incompatibility. Plant Cell 19, 107–117 (2007).

    CAS  Article  Google Scholar 

  4. 4

    Samuel, M. A., Yee, D., Haasen, K. E. & Goring, D. R. in Self-Incompatibility in Flowering Plants (ed. Franklin-Tong, V. E.) Ch. 8, 173–191 (Springer, 2008).

    Google Scholar 

  5. 5

    Samuel, M. A. et al. Cellular pathways regulating responses to compatible and self-incompatible pollen in Brassica and Arabidopsis stigmas intersect at Exo70A1, a putative component of the exocyst complex. Plant Cell 21, 2655–2671 (2009).

    CAS  Article  Google Scholar 

  6. 6

    Samuel, M. A. et al. Proteomic analysis of Brassica stigmatic proteins following the self-incompatibility reaction reveals a role for microtubule dynamics during pollen responses. Mol. Cell. Proteomics 10, M111.011338 (2011).

    Article  Google Scholar 

  7. 7

    Sankaranarayanan, S., Jamshed, M. & Samuel, M. A. Proteomics approaches advance our understanding of plant self-incompatibility response. J. Proteome Res. 12, 4717–4726 (2013).

    CAS  Article  Google Scholar 

  8. 8

    Thornalley, P. J. The glyoxalase system: new developments towards functional characterization of a metabolic pathway fundamental to biological life. Biochem. J. 269, 1–11 (1990).

    CAS  Article  Google Scholar 

  9. 9

    Thornalley, P. J. Protein and nucleotide damage by glyoxal and methylglyoxal in physiological systems--role in ageing and disease. Drug Metab. Drug Interact. 23, 125–150 (2008).

    CAS  Article  Google Scholar 

  10. 10

    Hosoda, F. et al. Integrated genomic and functional analyses reveal glyoxalase I as a novel metabolic oncogene in human gastric cancer. Oncogene 34, 1196–206 (2015).

    CAS  Article  Google Scholar 

  11. 11

    Morcos, M. et al. Glyoxalase-1 prevents mitochondrial protein modification and enhances lifespan in Caenorhabditis elegans. Aging Cell 7, 260–269 (2008).

    CAS  Article  Google Scholar 

  12. 12

    Hovatta, I. et al. Glyoxalase 1 and glutathione reductase 1 regulate anxiety in mice. Nature 438, 662–666 (2005).

    CAS  Article  Google Scholar 

  13. 13

    Kromer, S. A. et al. Identification of glyoxalase-I as a protein marker in a mouse model of extremes in trait anxiety. J. Neurosci. 25, 4375–4384 (2005).

    Article  Google Scholar 

  14. 14

    Veena, Reddy, V. S. & Sopory, S. K. Glyoxalase I from Brassica juncea: molecular cloning, regulation and its over-expression confer tolerance in transgenic tobacco under stress. Plant J. 17, 385–395 (1999).

    Article  Google Scholar 

  15. 15

    Ramaswamy, O., Pal, S., Guha-Mukherjee, S. & Sopory, S. K. Correlation of glyoxalase I activity with cell proliferation in Datura callus culture. Plant Cell Rep. 3, 121–124 (1984).

    CAS  Article  Google Scholar 

  16. 16

    Kraus, J. L. & Castaing, M. Inhibition of yeast glyoxalase I by biologically active peptides. Res Commun. Chem. Pathol. Pharmacol. 65, 105–110 (1989).

    CAS  PubMed  Google Scholar 

  17. 17

    Stone, S. L., Arnoldo, M. & Goring, D. R. A breakdown of Brassica self-incompatibility in ARC1 antisense transgenic plants. Science 286, 1729–1731 (1999).

    CAS  Article  Google Scholar 

  18. 18

    Stone, S. L., Anderson, E. M., Mullen, R. T. & Goring, D. R. ARC1 is an E3 ubiquitin ligase and promotes the ubiquitination of proteins during the rejection of self-incompatible Brassica pollen. Plant Cell 15, 885–898 (2003).

    Article  Google Scholar 

  19. 19

    Du, J., Zeng, J., Ou, X., Ren, X. & Cai, S. Methylglyoxal downregulates Raf-1 protein through a ubiquitination-mediated mechanism. Int. J. Biochem. Cell Biol. 38, 1084–1091 (2006).

    CAS  Article  Google Scholar 

  20. 20

    Bento, C. F., Marques, F., Fernandes, R. & Pereira, P. Methylglyoxal alters the function and stability of critical components of the protein quality control. PloS ONE 5, e13007 (2010).

    Article  Google Scholar 

  21. 21

    Shimakawa, G. et al. Why don't plants have diabetes? Systems for scavenging reactive carbonyls in photosynthetic organisms. Bioch. Soc. Trans. 42, 543–547 (2014).

    CAS  Article  Google Scholar 

  22. 22

    Maher, P. et al. Fisetin lowers methylglyoxal dependent protein glycation and limits the complications of diabetes. PloS ONE 6, e21226 (2011).

    CAS  Article  Google Scholar 

  23. 23

    Chen, M. & Thelen, J. J. The plastid isoform of triose phosphate isomerase is required for the postgerminative transition from heterotrophic to autotrophic growth in Arabidopsis. Plant Cell 22, 77–90 (2010).

    Article  Google Scholar 

  24. 24

    Mustafiz, A. et al. A unique Ni2+-dependent and methylglyoxal-inducible rice glyoxalase I possesses a single active site and functions in abiotic stress response. Plant J. 78, 951–963 (2014).

    CAS  Article  Google Scholar 

Download references


We thank Dr Douglas Muench for the epi-fluorescence microscope facility and Dr Andre Buret for the microplate reader. We also thank Dr Daphne Goring for ARC1 antisense transgenic lines. This work was supported by the Natural Sciences and Engineering Research Council of Canada grants and start-up funds from the University of Calgary to M.A.S.

Author information




S.S. and M.A.S. conceived and initiated the project. S.S. and M.A.S. designed the research; S.S. performed all the experiments, and M.J. was responsible for analysis of subcellular localization of GLO1 and confocal microscopy; S.S., M.J. and M.A.S. analysed the data; S.S. and M.A.S. wrote the manuscript. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Marcus A. Samuel.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Sankaranarayanan, S., Jamshed, M. & Samuel, M. Degradation of glyoxalase I in Brassica napus stigma leads to self-incompatibility response. Nature Plants 1, 15185 (2015).

Download citation

Further reading