10.1371/journal.pone.0026765 Darryl Hudson Darryl Hudson David Guevara David Guevara Mahmoud W. Yaish Mahmoud W. Yaish Carol Hannam Carol Hannam Nykoll Long Nykoll Long Joseph D. Clarke Joseph D. Clarke Yong-Mei Bi Yong-Mei Bi Steven J. Rothstein Steven J. Rothstein <em>GNC</em> and <em>CGA1</em> Modulate Chlorophyll Biosynthesis and Glutamate Synthase (<em>GLU1/Fd-GOGAT</em>) Expression in <em>Arabidopsis</em> Public Library of Science 2011 modulate chlorophyll biosynthesis glutamate synthase 2011-11-10 00:25:02 Dataset https://plos.figshare.com/articles/dataset/_GNC_and_CGA1_Modulate_Chlorophyll_Biosynthesis_and_Glutamate_Synthase_GLU1_Fd_GOGAT_Expression_in_Arabidopsis_/131502 <div><p>Chloroplast development is an important determinant of plant productivity and is controlled by environmental factors including amounts of light and nitrogen as well as internal phytohormones including cytokinins and gibberellins (GA). The paralog GATA transcription factors <em>GNC</em> and <em>CGA1/GNL</em> up-regulated by light, nitrogen and cytokinin while also being repressed by GA signaling. Modifying the expression of these genes has previously been shown to influence chlorophyll content in <em>Arabidopsis</em> while also altering aspects of germination, elongation growth and flowering time. In this work, we also use transgenic lines to demonstrate that <em>GNC</em> and <em>CGA1</em> exhibit a partially redundant control over chlorophyll biosynthesis. We provide novel evidence that <em>GNC</em> and <em>CGA1</em> influence both chloroplast number and leaf starch in proportion to their transcript level. <em>GNC</em> and <em>CGA1</em> were found to modify the expression of chloroplast localized <em>GLUTAMATE SYNTHASE</em> (<em>GLU1/Fd-GOGAT</em>), which is the primary factor controlling nitrogen assimilation in green tissue. Altering <em>GNC</em> and <em>CGA1</em> expression was also found to modulate the expression of important chlorophyll biosynthesis genes (<em>GUN4</em>, <em>HEMA1</em>, <em>PORB</em>, and <em>PORC</em>). As previously demonstrated, the <em>CGA1</em> transgenic plants demonstrated significantly altered timing to a number of developmental events including germination, leaf production, flowering time and senescence. In contrast, the <em>GNC</em> transgenic lines we analyzed maintain relatively normal growth phenotypes outside of differences in chloroplast development. Despite some evidence for partial divergence, results indicate that regulation of both <em>GNC</em> and <em>CGA1</em> by light, nitrogen, cytokinin, and GA acts to modulate nitrogen assimilation, chloroplast development and starch production. Understanding the mechanisms controlling these processes is important for agricultural biotechnology.</p> </div>