Researchers at Washington State University have discovered a novel regulatory mechanism, which not
only significantly increases seed oil production in seeds of plants, but can also improve plant stress
tolerance as well as modify a broad range of other developmental aspects.
The approach focuses on modifying the ability of a group of proteins called BPMs to recognize and trigger
the degradation of a wide range of substrate proteins. These substrate proteins are different
transcription factors and each one is responsible for regulating developmental aspects such as root and
shoot growth, flowering time, as well as seed size and seed oil content. These transcription factors also
increase plants’ ability to cope with a variety of abiotic and biotic stress conditions. The approach is to
downregulate BPM expression and therefore reduce BPMs’ ability to recognize their substrates (the
transcription factors) thus reducing their ability to trigger the substrates for degradation. This
downregulation of BPM is conducted by introducing artificial microRNA under the control of a seed specific
and inducible promoter. In addition, substrates can also be modified in a way such that they are
not recognized by BPM proteins. It thus becomes possible to engineer crop plants that are better able to
cope with otherwise detrimental environmental stressors, without affecting other unwanted
This approach is novel because basic transcription levels of the substrates are not directly changed, as
was previously attempted. Instead, the activity of these transcription factors are modified by changing
the amount of BPM proteins in the cell or their ability to recognize and interact with their substrates.
Loss of the BPM substrate adaptors has been shown by the inventors to significantly increase seed oil
content with levels of more than 100% in comparison to wild type. Furthermore, because BPM proteins
and their substrates are highly conserved among plant species, one can expect that this technology is
broadly applicable to crop plants in general.