MCA: Delineating molecular components and mechanisms for bacterial flagellin-induced immune responses in maize maize

Plants play a vital role in our society because they serve as major food sources for humans and are crucial in the production of medicine, textiles and biofuels. By 2050, the world’s population is predicted to increase by 35%. To feed this growing population, total crop production will need to double.

Thus, improving crop production is an important aspect for enhancing the economy and food security within the US and around the world. These important goals, however, are negatively impacted by the fact that plant pathogens greatly reduce crop yield and nutritional values. This work focuses on corn, also called maize, which is a crop species of high agronomical value for US farmers and a staple food around the world.

The goal of this work is to advance the limited understanding of how cellular components that are localized at the surface of corn cells detect and induce plant defenses when infected by bacterial pathogens during the early growth of corn plants. The proposed study will provide new understanding that will contribute to new strategies on how to establish resistance against diverse pathogens, thus likely be complementary to current breeding efforts.

In addition to its biological importance, this project will provide diverse training to better prepare early-career scientists to be successful members of the national scientific work force. Undergraduate students will be recruited in their first year into a lab that provides a stimulating, challenging and open environment and allows for both scientific and personal growth.

As a staple crop, Zea mays (maize) is of high agronomic importance worldwide; but infection by microbial pathogens can result in substantial yield loss. Disease-causing pathogens include bacteria whose motility and pathogenicity rely on their flagella composed of flagellin proteins. As one means to protect themselves against infection by flagellated bacteria, genomes of many dicots and monocots -including maize- encode for an evolutionary ancient immune receptor FLAGELLIN SENSING2 (FLS2), a plasma membrane-localized receptor kinase that detects bacterial flagellin or its active peptide flg22.

Flg22 perception by FLS2 initiates many host immune responses that contribute to bacterial growth restriction. The genetic basis and the molecular machinery underlying flagellin perception and signaling in maize, however, remain largely elusive. This project will advance the limited understanding of the molecular components and mechanisms that contribute to pattern (flg22)-triggered immune responses against flagellated bacteria in maize.

The objectives are to a) delineate if ZmFLS2 functions in flg22-responses in maize using reverse genetics and ZmFLS2 expression in Arabidopsis atfls2 mutant; b) define signaling potency of flg22 peptides in leaves and in roots of maize; and c) decipher if a maize ortholog of an Arabidopsis vesicular trafficking protein with roles in FLS2 trafficking to/from the plasma membrane functions in development and immune responses in maize. This grant will provide mentoring and research training for a postdoctoral research fellow and incoming fresh(wo)men as part of the Freshmen Research in Plants (FRIPS) program.

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.