Cupins: What are they for?

First, we ought to say what cupins are: cupins are proteins, part of a so-called superfamily that includes enzymes and non-enzyme polypeptides. Since the first members of this group were described in plants – the cereal seed storage proteins, the germins – they’ve been identified in a wide range of organisms. Aside from a role in seed biology (hence of interest to human nutrition, especially since some cupins are implicated in allergic responses), they have variously been suggested to be involved in floral induction, fruit ripening, somatic and zygotic embryogenesis, wood development, and nodulation in legumes, and in many abiotic stress responses, too. But one role that hadn’t previously been suggested was an involvement in plant responses to living in a radioactive environment. But that’s what Daša Gábrišová et al. appear to have found in third-generation flax (Linum usitatissimum) grown in radioactive soil near the site of the 1986 Chernobyl nuclear disaster.*

An Updated model for flax growth in radio-contaminated Chernobyl area.
An Updated model for flax growth in radio-contaminated Chernobyl area. Image by Daša Gábrišová et al. (2016)

Overall, they saw limited effects on growth of mature and developing flax seeds in that radio-contaminated environment. However, studying protein profiles in developing plants, they noticed pronounced increases in cupin fragments – in both second- and third-generation plants. This has led them to propose an updated model that suggests “alterations in cupin abundance during seed filling contribute to the growth and successful reproduction of flax in radio-contaminated Chernobyl area”. Another role to add to the ever-expanding list of cupin functions?

* And for thrill-seekers, we are happy to advise that the site of this nuclear incident was declared a ‘tourist attraction’ in 2011, and, according to Trip Advisor, a visit to reactor No. 4 is the top thing (of four…) to do on your next trip to Chernobyl!

[Ed. – For more on the remarkable story of plant resilience at the radioactively-challenged Chernobyl site, visit And for another view of biota and nuclear incidents, a Springer-published report entitled “Agricultural Implications of the Fukushima Nuclear Accident” that reviews the first three years after the 2011 Fukushima Daiichi nuclear power plant accident is available via Open Access. And for an assessment five years on from the date of the Fukushima incident, see Masahiro Sugiyamaet al.]

Further reading

François Bernier, Anne Berna, 2001, 'Germins and germin-like proteins: Plant do-all proteins. But what do they do exactly?', Plant Physiology and Biochemistry, vol. 39, no. 7-8, pp. 545-554

Madhan Masilamani, Scott Commins, Wayne Shreffler, 2012, 'Determinants of Food Allergy', Immunology and Allergy Clinics of North America, vol. 32, no. 1, pp. 11-33

Amjad Iqbal, Farooq Shah, Muhammad Hamayun, Ayaz Ahmad, Anwar Hussain, Muhammad Waqas, Sang-Mo Kang, In-Jung Lee, 2016, ' Allergens of Arachis hypogaea and the effect of processing on their detection by ELISA ', Food & Nutrition Research, vol. 60, no. 0

Jim M. Dunwell, J. George Gibbings, Tariq Mahmood, S. M. Saqlan Naqvi, 2008, 'Germin and Germin-like Proteins: Evolution, Structure, and Function', Critical Reviews in Plant Sciences, vol. 27, no. 5, pp. 342-375

Daša Gábrišová, Katarína Klubicová, Maksym Danchenko, Dušan Gömöry, Valentyna V. Berezhna, Ludovit Skultety, Ján A. Miernyk, Namik Rashydov, Martin Hajduch, 2016, 'Do Cupins Have a Function Beyond Being Seed Storage Proteins?', Frontiers in Plant Science, vol. 6

Kazunori Anzai, Nobuhiko Ban, Toshihiko Ozawa, Shinji Tokonami, 2011, 'Fukushima Daiichi Nuclear Power Plant accident: facts, environmental contamination, possible biological effects, and countermeasures', Journal of Clinical Biochemistry and Nutrition, vol. 50, no. 1, pp. 2-8

Masahiro Sugiyama, Ichiro Sakata, Hideaki Shiroyama, Hisashi Yoshikawa, Taketoshi Taniguchi, 2016, 'Research management: Five years on from Fukushima', Nature, vol. 531, no. 7592, pp. 29-31