Investigate the roles of endogenous salicylic acids in de novo organogenesis

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

Plants have the unique and important ability to regenerate a new organ or even an entire seedling from a small piece of tissue. This process of tissue regeneration is a foundation for modern agriculture and horticulture. The propagation of many fruits and vegetables heavily relies on techniques involving tissue regeneration, such as grafting, tissue culture, and rooting from stem cuttings. These techniques provide a non-transgenic approach to produce chimera or improved cultivars and, eventually, to increase plants' vigor and resistance to pathogens. Thus, understanding the underlying mechanisms of tissue regeneration is important for food quality and security. This study investigates how plant regeneration occurs under the influence of microbial pathogens, which are constant threats to our agriculture. New molecular and cellular technologies will be used to examine the function of plant hormones in regulating the balance of regeneration and defense against pathogens. Knowledge obtained from this study will promote practical and scalable strategies to help regeneration in species where wound-healing and regeneration after cutting remains a critical bottleneck for propagation. The proposed project will also provide students at different levels with experiential learning of modern plant biotechnology. This study aims to elucidate the role of salicylic acid (SA) in wound-induced de novo Root Regeneration (DNRR), in which adventitious roots form on detached leaves. De novo organogenesis is a fascinating developmental process involving a drastic transition of cell fate. The molecular crosstalk between pathways governing biotic stress and regeneration represents a major knowledge gap. A general hypothesis is that antagonistic interaction between NPR family members fine-tunes the SA-mediated suppression of DNRR. The following specific aims will be addressed. Aim1: Determine the spatiotemporal patterns of SA response and accumulation during DNRR. Aim2: Test the hypothesis that NPR3/4 and NPR5/6 antagonistically regulate DNRR. Aim3: Characterize the function of an NPR4-TGA complex in DNRR. Completion of the proposed study will establish foundational knowledge about how endogenous SA suppresses the cell fate transition during DNRR. Characterizing the contribution of NPR family members and their interactions with TGA transcription factors will expand our knowledge of the distinct and overlapping function of NPR proteins in SA- mediated defense and development. Plant regeneration is an intriguing developmental process for students to observe and to gain hands-on experience. Select partners involved in undergraduate and K-12 education will participate in this study to enhance the experiential learning of plant development, especially for underrepresented groups in STEM education. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.