Temporal network analysis identifies early physiological and transcriptomic indicators of mild drought in Brassica rapa

• Published in: eLife Vol. 6
• Main Authors: Greenham, Kathleen, Guadagno, Carmela Rosaria, Gehan, Malia A, Mockler, Todd C, Weinig, Cynthia, Ewers, Brent E, McClung, C Robertson
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 18.08.2017; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: abiotic stress; Agricultural production; Analysis; Biochemistry; Biomass; Brassica; Brassica rapa; Brassica rapa - genetics; Brassica rapa - physiology; Circadian rhythms; Climate; Climate change; Conductance; Crop production; Crops; daily rhythms; Drought; Droughts; Flowers & plants; Food; Food supply; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Plant; Genes; Genetic research; Global temperature changes; Molecular biology; Net losses; Photosynthesis; Photosystem II; Physiological aspects; Physiology; Plant biochemistry; Plant Biology; Plants (Organisms); Quantitative genetics; Stomata; Stress, Physiological; Time; transcriptomic network analysis; Water wells; Weather forecasting; United States > US; Brassica rapa; transcriptomic network analysis; daily rhythms; drought; photosynthesis; plant biology; abiotic stress
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/elife.29655

The dynamics of local climates make development of agricultural strategies challenging. Yield improvement has progressed slowly, especially in drought-prone regions where annual crop production suffers from episodic aridity. Underlying drought responses are circadian and diel control of gene expression that regulate daily variations in metabolic and physiological pathways. To identify transcriptomic changes that occur in the crop during initial perception of drought, we applied a co-expression network approach to associate rhythmic gene expression changes with physiological responses. Coupled analysis of transcriptome and physiological parameters over a two-day time course in control and drought-stressed plants provided temporal resolution necessary for correlation of network modules with dynamic changes in stomatal conductance, photosynthetic rate, and photosystem II efficiency. This approach enabled the identification of drought-responsive genes based on their differential rhythmic expression profiles in well-watered versus droughted networks and provided new insights into the dynamic physiological changes that occur during drought.