Open Access Open Badges Research article

Beneficial ‘unintended effects’ of a cereal cystatin in transgenic lines of potato, Solanum tuberosum

Aurélie Munger1, Karine Coenen1, Line Cantin1, Charles Goulet12, Louis-Philippe Vaillancourt1, Marie-Claire Goulet1, Russell Tweddell1, Frank Sainsbury1 and Dominique Michaud1*

Author Affiliations

1 Centre de recherche en horticulture, Département de phytologie, Université Laval, Pavillon des Services, 2440 boul. Hochelaga, Québec, QC,, G1V 0A6, Canada

2 Current address: Horticulture Sciences Department, University of Florida, Gainesville, FL, 32611, USA

For all author emails, please log on.

BMC Plant Biology 2012, 12:198  doi:10.1186/1471-2229-12-198

Published: 1 November 2012



Studies reported unintended pleiotropic effects for a number of pesticidal proteins ectopically expressed in transgenic crops, but the nature and significance of such effects in planta remain poorly understood. Here we assessed the effects of corn cystatin II (CCII), a potent inhibitor of C1A cysteine (Cys) proteases considered for insect and pathogen control, on the leaf proteome and pathogen resistance status of potato lines constitutively expressing this protein.


The leaf proteome of lines accumulating CCII at different levels was resolved by 2-dimensional gel electrophoresis and compared with the leaf proteome of a control (parental) line. Out of ca. 700 proteins monitored on 2-D gels, 23 were significantly up- or downregulated in CCII-expressing leaves, including 14 proteins detected de novo or up-regulated by more than five-fold compared to the control. Most up-regulated proteins were abiotic or biotic stress-responsive proteins, including different secretory peroxidases, wound inducible protease inhibitors and pathogenesis-related proteins. Accordingly, infection of leaf tissues by the fungal necrotroph Botryris cinerea was prevented in CCII-expressing plants, despite a null impact of CCII on growth of this pathogen and the absence of extracellular Cys protease targets for the inhibitor.


These data point to the onset of pleiotropic effects altering the leaf proteome in transgenic plants expressing recombinant protease inhibitors. They also show the potential of these proteins as ectopic modulators of stress responses in planta, useful to engineer biotic or abiotic stress tolerance in crop plants of economic significance.

Transgenic crops; Transgene pleiotropy; Unintended effects; Stress/defense-related proteome; Corn cystatin; Potato (Solanum tuberosum)