The effects of fluctuations in the nutrient supply on the expression of ANR1 and 11 other MADS box genes in shoots and roots of Arabidopsis thaliana
We previously reported that the response of ANR1 expression in shoots to nitrogen (N) starvation and resupply was different from its response in roots. However, how the other root-expressed MADS box genes respond to different N fluctuations in the shoot, and how these MADS box genes respond to complete nutrient fluctuations in the root, were unknown. Results from this study have shown that some members of these root-expressed MADS box genes have different responses in the shoot and root to N treatments, whereas others have similar responses or no responses to the N treatments. Among these 12 root-expressed MADS box genes, AGL16 was the only gene to show a similar response to N fluctuation in both shoots and roots in the same way as ANR1. Results from this study have also shown that ANR1, AGL12, AGL16, AGL19, and SOC1 responded to changes of the complete nutrient condition, which might indicate that they could play key roles in general nutrient stress. These novel findings will help us to further characterize these 12 MADS box genes to uncover the complex regulatory networks that integrate plant responses to changes in nutrient availability.