<i>MPF2-like</i> promoter activates the expression of YFP/GUS, while large 1^st intron suppresses it. A

<p>) <i>MPF2-like</i> long promoter was attached with GUS and YFP reporter genes and expressed stably and transiently in <i>Arabidopsis</i> and <i>Nicotiana</i>, respectively. The GUS signals driven by <i>Withania MPF2-like-A</i> and -<i>B</i> promoter are equally strong in the inflorescence though native expression for <i>MPF2-like-B</i> is barely detectable. Similarly YFP signals are very strong in both types of promoters. The scale bar represents 4 mm and 30 µm for GUS and YFP pictures, respectively. <b>B</b>) A transient YFP expression assay was performed under the control of <i>MPF2-like</i> long promoter and complete large 1^st intron (<i>MPF2-like^PL:YFP</i>; <i>MPF2-like^I:^PL:YFP</i>). Three days after infiltration, leaves of <i>N. benthamiana</i> were scanned under Leica LCS SP2 AOBS^R, Confocal Laser Scanning Microscope (CLSM) for YFP signal detection. At least 10 images selected randomly to quantify the luminescence with the Leica software LCS Lite. Promoter strength was determined as the relative intensity of YFP fluorescence of nuclear area of <i>MPF2-like</i> promoter YFP constructs in comparison with nuclear YFP fluorescence intensity of a 35 S CaMV promoter YFP construct. In the case of <i>WSB206-like^I:^PL:YFP</i> there is a tremendous decrease in YFP signal intensity after attaching <i>MPF2-like</i> large 1^st intron with promoter region. The error bars represent the standard deviation. <b>C</b>) Confocal images showing YFP expression driven under <i>MPF2-like cis</i>-elements in the nuclei of the transiently transformed <i>Nicotiana</i> leaves. The scale bar represents 30 nm.