The original publication of this article included an error in Figure 5A. Specifically, the "MCPs" and "Roots" lanes were inappropriately reversed and duplicated as the "Siliques" and "Seeds" lanes. The authors apologize and accept responsibility for not detecting and correcting this issue prior to publication. The revised Figure 5A (lower panel) is the result of a new experiment that corrects the information in the original Figure 5A (upper panel). The figure legend provides methodological details of the new experiment. The original conclusion from this experiment, that expression "could be detected in all cell/tissue types assessed by RT-PCR, including stomatal guard cells (Figure 5A)," as stated in the main text of the article, is unaltered by this correction. Both authors approve this correction. Editors' note: The corrected figure and accompanying text were reviewed by members of The Plant Cell editorial board. The authors are responsible for providing a complete listing and accurate explanations for all known errors or instances of inappropriate data handling or image manipulation associated with the original publication. (Figure Presented).