Differential Expression of Maize Memory Genes in Response to Priming and Cold Stress

Undergraduate #21
Discipline: Biological Sciences
Subcategory: Plant Research

Raeann Goering - Hamline University
Co-Author(s): Gabe Drees and Jennie Kiebler, Hamline University, St Paul, MN

Acclimating plants to abiotic conditions is a phenomenon that can be observed in nature throughout changing seasons as well as within lab settings. Plants can adjust to abiotic stresses through biochemical changes controlled by transcription of genes. Trained plants can be produced by pre-exposing them to a lesser stress, allowing them to recover, then exposing them to a greater, longer stress. It is hypothesized that trained plants will tolerate the second harder stress more than untrained plants. In this experiment, B73 Maize seedlings were trained to cold stress while their growth, and greenness were measured to determine plant health. Four treatment groups with over sixty replicates were tested; Primed and Stressed, Primed, Stressed, and Control. Half of these plant’s growth was measured daily as total height, and finally sacrificed at the end of the cold stress protocol to obtain a percentage representing green area of the 3rd leaf through image analysis and a chlorophyll concentration per gram through methanol extraction and absorbance calculations. The other half was sacrificed after 2 hours of final stress for RNA extraction to be RNA sequenced. The results showed that priming offered no benefits to the maize seedlings immediately after stress. Primed and Stressed plants responded very similarly to Stressed plants both phenotypically and transcriptomically. However, when allowed to grow and recover after the final stress, Primed and Stressed plants recovered faster than Stressed plants indicating that priming may have a more beneficial effect during stress recovery than stress tolerance. In the future, phenotypic and transcriptomic analysis should be conducted during the stress recovery period.

Funder Acknowledgement(s): Plant Genome NSF Program (PGRP1444456, PGRP1237931)

Faculty Advisor: Irina Makarevitch, imakarevitch01@hamline.edu

Role: This project was shared by myself and two other students. I began the research 3 months before the other two. This time was used to develop an effective training protocol. This experience allowed me to take on a leadership role within our lab. I largely conducted data analysis using data collected by the group.