Methods to modify plant stress responses and enhance expression of target proteins

Unmet Need

There are over 8 billion people on our planet today that rely on several crops, including rice, corn, and wheat, as a primary source of sustenance. However, global climate change and the increased frequency of extreme weather events, such as droughts and floods, threaten to destabilize many of these sources of food on which so many populations depend. Already, climate change is a major contributor to world hunger, which affects approximately 10% of the world population. The challenges associated with food insecurity will only be exacerbated as the world population continues to grow; it is estimated to exceed 10 billion by 2060. There is a need for methods that modify plants to be more resilient to environmental perturbation such as temperature shifts, changing microbe environments, and changes in water availability. There is also a need for methods to enhance the expression of targeted proteins to improve plant stress responses and facilitate desired growth outcomes.

Technology

Duke inventors have developed molecular methods to modify plant stress responses and enhance expression of certain proteins. This is intended to be used by biotechnology companies and other entities developing stress-resistant crops. These stress-resistant plants have the potential to increase crop yields, reduce the cost of production, and reduce the use of pesticides. Specifically, Duke inventors found that plants respond to stress through a different pathway from that which is typically observed in eukaryotic stress responses. The key protein that they found mediates defense-mRNA translation, such that over-expression of the protein may enhance the plant response to abiotic and biotic factors. Duke inventors also identified upstream open reading frames (uORFs), which are sequence elements that allow for the rapid upregulation of defense protein production under conditions of stress. This has been demonstrated in the model plant species, Arabidopsis thaliana, in which the protein of interest was found to inhibit general translation and activate defense mRNA translation. Defense mRNA translation was found to be mediated by highly structured sequence elements that under normal conditions inhibit main open reading frames (mORFs), which contain the sequence for defense protein production. Under stress conditions, inventors found that the inhibition was bypassed through the unwinding of the inhibitory complex allowing for the upregulation of the defense proteins.

Advantages

• Key protein discovered in stress-response pathway has potential as a generalist to be widely applicable across a diversity of plants/crops in regulating stress-response
• Discovery of feature in the mRNA structure rather than in the sequence as a mechanism for translation initiation and downstream protein synthesis
• Protein synthesis regulation could be widely applicable across eukaryotes