Overexpression of <i>BnaAGL11</i>, a MADS-Box Transcription Factor, Regulates Leaf Morphogenesis and Senescence in <i>Brassica napus</i>

Abstract

Previous studies have reported that SEEDSTICK/AGAMOUS-LIKE 11 (AtSTK/AtAGL11), a MADS-box transcription factor, plays important roles in many biological processes in <i>Arabidopsis thaliana</i>. However, the function of <i>BnaAGL11</i>, an <i>AtAGL11</i> homologous gene from <i>Brassica napus</i>, in leaf development remains unknown. Here, we found that the ectopic expression of any copy of <i>Bna.C09.AGL11</i>, <i>Bna.A03.AGL11</i>, and <i>Bna.A09.AGL11</i> in <i>A. thaliana</i> led to smaller and curly leaves and promoted leaf senescence. Consistently, the overexpression of <i>Bna.C09.AGL11</i> in <i>B. napus</i> also caused smaller and curly leaves and accelerated leaf senescence. Furthermore, we demonstrated that Bna.C09.AGL11 controlled leaf morphogenesis by indirectly downregulating the genes of <i>Bna.A01.DWF4</i> and <i>Bna.C07.PGX3</i> and promoted leaf senescence by indirectly upregulating the genes of <i>Bna.A04.ABI5</i>, <i>Bna.A05.ABI5</i>, <i>Bna.C04.ABI5-1</i>, and <i>Bna.C01.SEN4</i> and directly activating the transcription of <i>Bna.C04.ABI5-2</i> and <i>Bna.C03.SEN4</i> genes. Our results provide new insights into the underlying regulatory mechanism of <i>BnaAGL11</i> during leaf development in <i>B. napus</i>.