PSLA Lecture Series: Dr. Jenny Kao-Kniffin
Figure 1. The life cycle of A. thaliana plants. Pictorial depiction from seed to reproductive growth. (Kramer, 2015)
The influence of soil microbiomes on plant traits
On Thursday April 13, 2017, Dr. Jenny Kao-Kniffin Assistant Professor of the School of Integrative Plant Science at Cornell University was featured as guest speaker for the University of Maryland’s Plant Science and Landscape Architecture’s Seminar Series talk. Dr. Kao-Kniffin received a PhD in Land Resources from the University of Wisconsin-Madison. In 2010 she became an Assistant Professor at Cornell University in Ithaca, NY. Her lab at Cornell studies the belowground ecology and management of weedy and invasive plants. Her lecture explored many projects from her lab such as how plant-associated microorganisms contribute to weed suppression and how to manage weeds without routinely applying pesticide.
In her research, she assembles microbes from uncultivated samples and tests whether altering soil microbes modifies plant traits. Microbial communities are adaptive units and plants are the recorders of microbial activity. Through generations of selection, the microbial community in the potted rhizophere is an adaptive unit. Plant phenotypes such as flowering time were tested in different cultivated microbiomes. In plant communities, a significant divergence in the mean number of days until flowering time was seen. Arabidopsis thaliana genotypes Ler Be, and RLD showed an increase of inflorescence biomass when exposed to microbiomes associated with late flowering. Additionally, the study revealed that there was increased extracellular activity in the microbiomes of the later flowering plants compared to the early flowering counterparts. Further, two- to five-fold activity increase was seen in NAG (N-acetyl glucosaminidase), LAP (Leucine aminopeptidade), and POX (Phenol oxidase) in the late flowering microbiome soils. The study concludes that plant biomass levels are differentially altered from microbiomes from different selection lines and the overall microbiome composition is seen to change over the course of selection. Also, after five generations, there was a decline in microbial diversity. This suggests that in order to reach community stability, there needs to be additional iterations of selection. Further research should investigate the mechanisms that underlie microbiome-influenced shifts in flowering time (Panke-Buisse et al., 2015). Perhaps in the future plant productions systems can be manipulated using specific micriobiomes to give rise to agronomically-preferred traits.
References
Panke-Buisse, K. (2015). Selection on soil microbiomes reveals reproducible impacts on plant function. Isme Journal,9, 980-989.
Kramer, U. (2015). Planting molecular functions in an ecological context with arabidopsis thaliana. Elife,4. doi:10.7554/eLife.06100
