Plant Immunity | Texas A&M AgriLife Dallas Center

Contact Dr. Junqi Song at junqi.song@ag.TAMU.edu for information about the plant immunity research program.

ORCID iD icon orcid.org/0000-0002-2555-3408

The plant biotic stress research laboratory at the Texas A&M AgriLife Research and Extension Center of Dallas is uniquely focused on how plants perceive and respond to microbial pathogens by combining molecular, genetic, biochemical, genomic and proteomic approaches.

Our long-term research goal is to understand the complex network of signal transduction and pathway interactions in plant immunity.

The knowledge generated from these studies will contribute to a better understanding of microbial pathogenesis and host defense responses, which should ultimately lead to the development of novel disease control strategies and improved crop production.

The functional interplay between DNA damage repair and plant immunity

The plant immune and DNA damage responses are two ancient fundamental surveillance mechanisms. Although both responses have been well characterized separately, the relationship between them is largely unknown. Dr. Song’s group and others have identified multiple DNA damage proteins that play a key role in plant immune response. The laboratory's future research will continue to investigate how DNA damage proteins regulate plant immune response and how the two responses are intricately interconnected.

The molecular basis of how poly(ADP-ribosyl)ation regulates immune and stress responses

Poly(ADP-ribosyl)ation is a posttranslational modification of nuclear proteins catalyzed by poly(ADP-ribose) polymerase (PARP) and plays a role in nearly all major cellular processes, including DNA repair, transcription, translation, chromatin remodeling, metabolic regulation and cell death. Recent findings indicate that poly(ADP-ribosyl)ation is an important component of plant immunity and is a dynamic process that is tightly controlled and fine-tuned. A core component of our research program will identify the mechanisms through which poly(ADP-ribosyl)ation regulates plant immune and stress responses and discover new components and pathways with functional roles in plant immunity, in particular by identifying PARP targets and associated proteins and investigating the functional interplay of PARPs with their interactors. Future studies will investigate how PARPs mutually modulate the expression of each other and elucidate the molecular mechanism by which PARPs and PARGs regulate various cellular responses, individually or in a concerted manner.

The molecular mechanism of plant-fungus/oomycete interactions

Fungal and oomycete pathogens are responsible for many devastating diseases in plants. For example, Phytophthora infestans is a destructive oomycete pathogen best known for causing Irish Potato Famine and remains the most costly potato pathogen to control worldwide. Two notorious fungal pathogens, Rhizoctonia solani and Sclerotinia homoeocarpa, cause large patch and dollar spot in turfgrass, respectively. Genome sequence analyses of these pathogens have identified an array of effector proteins that are translocated into host cells to establish infection. The pathogenic mechanisms of the majority of these secreted effectors remain unknown. The aim of his research is to identify the virulence targets and mode of action of these effectors. Increased understanding of the molecular basis of plant-pathogens interactions will facilitate development of sustainable management strategies against these destructive fungal and oomycete pathogens in crops.