Generation of temperature gradient on microfluidic plant chip for high-throughput plant phenotyping

This paper reports a simple and effective method for generating a stable temperature gradient on a microfluidic plant chip. A thermo-electric cooling (TEC) plate is horizontally placed below an inclined microfluidic plant chip. The space between the TEC and the plant chip is filled with polydimethylsiloxane (PDMS). Due to different lengths of thermal pathways from the TEC to the plant chip, a stable temperature distribution is realized on the plant chip without using any feedback circuits. This present temperature gradient generation method is highly economical and accessible and can facilitate to study influences of environmental temperature changes on many microorganisms and small model plants. As an application demonstration, we present the germination and early-stage growth of Arabidopsis thaliana plant, an important model plant in the area of biology, under various temperature conditions.