Abstract: The present inventors have discovered that Thioredoxin (TRX) is essential for plant growth. Specifically, the inhibition of TRX gene expression in plant seedlings results in seedling deformities, reduced and severely stunted growth, and chlorosis. Thus, TRX can be used as a target for the identification of herbicides. Accordingly, the present invention provides methods for the identification of compounds that inhibit TRX expression or activity, comprising: contacting a compound with a TRX and detecting the presence and/or absence of binding between said compound and said a TRX, or detecting a decrease in TRX expression or activity. The methods of the invention are useful for the identification of herbicides.