High throughput in vitro seed germination screen identified new ABA responsive RING-type ubiquitin E3 ligases in Arabidopsis thaliana

• Published in: Plant cell, tissue and organ culture tissue and organ culture, 2019-12, Vol.139 (3), p.563-575
• Main Authors: Pavicic, M., Wang, F., Mouhu, K., Himanen, K.
• Format: Article
• Language: English
• Subjects: Abscisic acid; Assaying; Biomedical and Life Sciences; Chlorophyll; Fluorescence; Genetic analysis; Germination; Life Sciences; Menopause; Mutants; Original Article; Physical characteristics; Physical properties; Physiology; Plant Genetics and Genomics; Plant hormones; Plant Pathology; Plant Physiology; Plant Sciences; Quality management; Seed germination; Seedlings; Seeds; Transcription; Ubiquitin; Ubiquitin-protein ligase
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-019-01700-9

Seed quality is an important factor for seedling vigour as well as adult plant resilience. The key quality attributes are related to physical characteristics, physiological performance, genetic background and health status of the seeds. Many ways to address seed quality attributes have been developed and recently many of them have featured automated high throughput methods. In our study, we addressed two of the seed quality attributes, namely physiological performance and genetic background by analysing germination rates in our mutant collection. These mutants represent ubiquitin E3 ligases that transcriptionally respond to abscisic acid (ABA). This plant hormone is an important regulator of germination and seedling establishment. To facilitate in vitro germination screens of large seed collections a high throughput image-based assay was developed. As a read out of the germination on ABA treatment the cotyledon emergence was detected with top view chlorophyll fluorescence camera. By applying the ABA treatment during germination, RING-type ubiquitin E3 ligase mutants were identified, showing either resistant or sensitive responses to ABA. In conclusion, a scalable high throughput screen for in vitro germination assay was established that allowed fast screening of tens of mutants in a hormone supplemented media. Key message To assign ubiquitin E3 ligases to ABA pathway a high throughput chlorophyll fluorescence-based germination assay was established. Screen identified novel ABA response ubiquitin E3 ligases with opposite responses.