Kathleen M. Brown, Ph.D.

Research Interests

We are interested in root traits that influence crop performance under soil stresses such as drought and nutrient deficiency. The placement of roots in soil determines what resources they can access, e.g. the topsoil typically has more phosphorous, while deeper soil layers typically have more available water under drought conditions. Root architectural traits determine what parts of the soil are explored and therefore what resources can be acquired by those roots.

We study root anatomical traits, such as aerenchyma, that can affect the metabolic cost of the roots. Since roots use fixed carbon and mineral nutrients, making cheaper roots can increase the availability of limiting resources for additional root growth or other uses such as yield. We are also interested in structure-function relationships of xylem traits in roots.

Root hairs are another trait of interest. Root hairs increase the volume of soil explored at minimal additional cost, and are therefore important, especially for diffusion-limited resources like phosphorus.

In our lab, we study how these traits develop, the genetic variation for the traits, their impact on water and nutrient acquisition, the interaction among traits, and the possible tradeoffs for each trait. We develop simple screens and genetic markers that can be used by plant breeders to improve the performance of crops in stressed soils. Currently we are using genome-wide association mapping to identify candidate genes involved in development of root traits, and CRISPR to validate some candidates. We do research in the lab, greenhouse and field . The crops we work on are maize, common bean, and rice. Our goal is to improve the efficiency of water and nutrient use in the USA and in the world, thereby reducing hunger and environmental degradation.

See the Roots Lab website http://plantscience.psu.edu/research/labs/roots for a list of publications, projects, and research methods.

Please note that I am no longer accepting new graduate students or visiting scholars.

Teaching

HORT 412w Postharvest Physiology, 3 credits, every spring semester

AGRO 555 Effective Scientific Communication, 2 credits, every fall semester

HORT 296/496/596 Undergraduate and graduate research experience

I also participate in the Intercollege Graduate Program in Plant Biology.