A rapid assay for assessing bacterial effects on Arabidopsis thermotolerance

• Published in: Plant methods Vol. 19; no. 1; p. 63
• Main Authors: Lee, Jun Hyung, Burdick, Leah H, Piatkowski, Bryan, Carrell, Alyssa A, Doktycz, Mitchel J, Pelletier, Dale A, Weston, David J
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 29.06.2023; BioMed Central; Springer Science + Business Media; BMC
• Subjects: Analysis; Arabidopsis; Arabidopsis thaliana; Bacteria; Chlorophyll; Chlorophyll content; Climate change; Flowers & plants; Genetic aspects; Genetic diversity; Genetic variance; Germination; Growth conditions; Heat; Heat shock; Heat stress; High-throughput; Host plants; Hydroponics; Identification and classification; Methodology; Methods; Microorganisms; Phenotypes; Phenotyping; Physiology; Plant growth; Plant heat tolerance; Productivity; Rapid assay; Reproducibility; Seedlings; Seeds; Strains (organisms); Temperature tolerance; Thermotolerance; United States; High-throughput; Chlorophyll content; Phenotyping; Plant-microbe interactions; Heat stress; Thermotolerance; Rapid assay
• ISSN: 1746-4811; 1746-4811
• DOI: 10.1186/s13007-023-01022-0

The role of beneficial microbes in mitigating plant abiotic stress has received considerable attention. However, the lack of a reproducible and relatively high-throughput screen for microbial contributions to plant thermotolerance has greatly limited progress in this area, this slows the discovery of novel beneficial isolates and the processes by which they operate. We designed a rapid phenotyping method to assess the effects of bacteria on plant host thermotolerance. After testing multiple growth conditions, a hydroponic system was selected and used to optimize an Arabidopsis heat shock regime and phenotypic evaluation. Arabidopsis seedlings germinated on a PTFE mesh disc were floated onto a 6-well plate containing liquid MS media, then subjected to heat shock at 45 °C for various duration. To characterize phenotype, plants were harvested after four days of recovery to measure chlorophyll content. The method was extended to include bacterial isolates and to quantify bacterial contributions to host plant thermotolerance. As an exemplar, the method was used to screen 25 strains of the plant growth promoting Variovorax spp. for enhanced plant thermotolerance. A follow-up study demonstrated the reproducibility of this assay and led to the discovery of a novel beneficial interaction. This method enables rapid screening of individual bacterial strains for beneficial effects on host plant thermotolerance. The throughput and reproducibility of the system is ideal for testing many genetic variants of Arabidopsis and bacterial strains.