Pennycress is related to the model plant species "Arabidopsis thaliana". Light is the flowering signal of "Arabidopsis thaliana". Significant progress has been made in understanding DNA methylation in the model plant "Arabidopsis thaliana". Scientists tested this method using the "Arabidopsis thaliana" plant. Experiments have been performed in "Arabidopsis thaliana". Phototropism in plants such as "Arabidopsis thaliana" is directed by blue light receptors called phototropins. This effect was exploited to improve gene targeting (GT) efficiency in "Arabidopsis thaliana". The model is based upon studies of mutants in "Arabidopsis thaliana" and snapdragon, "Antirrhinum majus". TILLING was introduced in 2000, using the model plant "Arabidopsis thaliana". Nutrient and/or vitamin supplementation for "Arabidopsis thaliana" is standard across most experimental conditions. Lab-on-a-chip devices could be used to characterize pollen tube guidance in Arabidopsis thaliana. Plants, such as "Arabidopsis thaliana," have a particularly great diversity of isoforms. The first plant genome sequenced was that of "Arabidopsis thaliana" which encodes about 25,500 genes. The mitochondrial genome of "Arabidopsis thaliana" is 367,808 base pairs long and contains 57 genes. Plant development has focused on the thale cress "Arabidopsis thaliana" as a model organism.