Light as an energy source is essential for plants to synthesize their food from water and carbon dioxide, known as photosynthesis. Mutual shading of plants growing at high planting density triggers competition for sunlight. In response to shading, plants use resources to grow taller to outperform neighbor competitors and elevate their leaves above the plant canopy to full sunlight to continue photosynthesis. The resources that should be used by the plants to produce grains and fruits that we eat are thus used for stem elongation. However, excessive stem growth is good for crops such as sugarcane and sorghum that are grown for sugars or biomass for biofuels. Identifying the molecular mechanisms and genes that control stem elongation in response to shade will help us develop crops with the desired stem size. Besides stem growth, plants also stop growing branches and flower earlier in response to shading, a phenomenon known as the shade avoidance syndrome (SAS). In this seminar, I will present how plants continuously monitor their proximity to neighbors and activate the shade avoidance syndrome developmental program before they are shaded. I will also demonstrate how RNA-seq is advancing our knowledge of the molecular mechanisms and genes that control stem elongation in response to shade.
Dr. Tesfamichael Kebrom is a research scientist with a joint appointment at the Center for Computational Systems Biology (College of Engineering) and the Cooperative Agricultural Research Center (College of Agriculture and Human Sciences) at Prairie View A&M University (PVAMU). He received B.SC in Plant Sciences from the University of Asmara in Eritrea, M.Phil. (Master of Philosophy) in Crop Physiology from the University of Reading in the UK, and Ph.D. in Molecular & Environmental Plant Sciences from Texas A&M University. His research focuses on identifying molecular pathways and gene regulatory networks controlling shoot branching and stem growth in response to environmental and developmental signals in the grasses using plant systems biology approaches.