Bing Yang, associate professor in GDCB, was awarded sponsored funding for three research projects on rice plant disease.  Rice, a major food source for the world population, presents an excellent opportunity for in-depth analyses of the adaptive processes of plant disease susceptibility.  In particular, the bacterium of Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of bacterial blight diseases of rice. The bacterium causes disease, in part, modulating host gene expression utilizing a remarkable repertoire of transcription activation-like (TAL) effectors. TAL effectors are proteins synthesized in bacteria and transferred to plant cells during the infection process.  The long term goal of research in Prof. Yang’s laboratory is to better understand the plant disease, and gain knowledge to aid the design of more intelligent breeding strategies for disease control by blocking the host disease susceptibility pathway in addition to deployment of genetic disease resistance genes in crop plants.

Dr. Yang is a Co-PI on the first National Science Foundation (NSF) sponsored award to Frank White (Kansas State University) to study TAL effectors, entitled “TAL Effector Targeting in Plant Genomes.”  Professor Adam Bogdanove, formerly of Iowa State University, now with Cornell University, and Professor Volker Brendel, formerly of GDCB, now with Indiana University are the other Co-PIs on this research project.  Dr. Yang will receive $793,753 for three years for the research project entitled “TAL effector targeting in plant genomes.” This project will elucidate the processes in rice susceptibility and resistance to bacterial blight, and establish important, broadly relevant concepts of plant-pathogen interactions and TAL effector biotechnology. The results will provide insight into strategies for achieving durable and broad resistance against disease, which, in itself, can have wide-reaching impacts on the environment and quality of life.

The second NSF sponsored award for $461,814 over three years is for Dr. Yang’s research project entitled, “Collaborative Research: The role of host nutrient carriers in pathogen susceptibility.”  Bacterial and fungal pathogens inflict major crop losses. The bacterium Xoo, the causal agent for bacterial blight of rice, affects yield stability with losses up to 60% in the developing world. Three groups with complementary expertise have identified a fundamental mechanism for plant disease susceptibility involving Xoo-induced expression of sugar transporters known as SWEETs. SWEETs are involved in the translocation of sugars from photosynthetic leaves to roots, pollen, and seeds in uninfected plants. Xoo directly induces SWEET gene expression using TAL (transcription factor-like) effector proteins, which are injected from bacterium into leaf cells. The research team has also shown that genetic alterations affecting TAL effector function through genomic editing of the target sequence in the host can be used to engineer pathogen resistance. The research team hypothesizes that growth of the pathogen depends critically on nutrient supply from the host, and that Xoo specifically targets sugar release from leaf cells for supplying carbon and energy to the pathogen.  They also hypothesize that this mechanism is relevant for other host/pathogen systems.  This work lays the basis for engineering robust and broad disease resistance by targeting SWEETs encoded by a family of ~20 genes in rice and other crops. The results are expected to provide insight into durable and broad resistance and have global impacts on the environment and quality of life.

The third sponsored award for $33,000 by the Carnegie Institution for Science under the Bill and Melinda Gates Foundation Grant Challenges Explorations Grant is for Dr. Yang’s research project, entitled “Transformative Strategy for Controlling Rice Disease in Developing Countries.”   Wolf B. Frommer, director of Carnegie’s Department of Plant Biology, jointly with Dr. Yang and Dr. Frank White from Kansas State University, proposed the innovative global health and development research project which seeks to test the idea of engineering broad and durable resistance in rice by testing the spectrum of resistance to a collection of Xoo strains, 40 strains of which have been obtained through collaboration worldwide, in their SWEET14-modified rice.  Modifying the S gene SWEET11 and SWEET14-modified rice to evaluate the plant’s resistance to pthX01-dependent Xoo infection, set up a network across developing countries for collection of Xoo isolates, and phenotypic evaluation of the new lines regarding yield and sugar transport physiology.