When Defense Pathways Collide. The Response of Arabidopsis to a Combination of Drought and Heat Stress

• Published in: Plant physiology (Bethesda) Vol. 134; no. 4; pp. 1683 - 1696
• Main Authors: Ludmila Rizhsky, Hongjian Liang, Joel Shuman, Shulaev, Vladimir, Sholpan Davletova, Mittler, Ron
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.04.2004; American Society of Plant Physiologists
• Subjects: Acclimatization; Acclimatization - genetics; Acclimatization - physiology; Adaptation to environment and cultivation conditions; Agronomy. Soil science and plant productions; Arabidopsis; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; bioaccumulation; Biological and medical sciences; Carbohydrate Metabolism; chemical constituents of plants; Dehydrogenases; Disasters; Drought; Economic plant physiology; Environmental Stress and Adaptation; Fundamental and applied biological sciences. Psychology; gene expression regulation; Gene Expression Regulation, Plant; Generalities. Disease free stocks; Genes; Genes. Genome; genetics; Genetics and breeding of economic plants; Glucose; Glucose - metabolism; Heat shock proteins; heat stress; Heat stress disorders; Hot Temperature; Leaves; Maltose; Maltose - metabolism; messenger RNA; metabolism; metabolomics; Molecular and cellular biology; Molecular genetics; physiology; Phytopathology. Animal pests. Plant and forest protection; plant extracts; plant genetics; plant proteins; plant response; plant stress; Plants; proline; Proline - metabolism; resistance mechanisms; RNA; Seedlings; sucrose; Sucrose - metabolism; Transcription factors; transcriptome; Varietal selection. Specialized plant breeding, plant breeding aims; Water relations, transpiration, stomata; water stress; Cruciferae; Arabidopsis; Toxicity; Dicotyledones; Angiospermae; Spermatophyta; Habitat; Drought; Stress
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.103.033431

Within their natural habitat, plants are subjected to a combination of abiotic conditions that include stresses such as drought and heat. Drought and heat stress have been extensively studied; however, little is known about how their combination impacts plants. The response of Arabidopsis plants to a combination of drought and heat stress was found to be distinct from that of plants subjected to drought or heat stress. Transcriptome analysis of Arabidopsis plants subjected to a combination of drought and heat stress revealed a new pattern of defense response in plants that includes a partial combination of two multigene defense pathways (i.e. drought and heat stress), as well as 454 transcripts that are specifically expressed in plants during a combination of drought and heat stress. Metabolic profiling of plants subjected to drought, heat stress, or a combination of drought and heat stress revealed that plants subject to a combination of drought and heat stress accumulated sucrose and other sugars such as maltose and gulose. In contrast, Pro that accumulated in plants subjected to drought did not accumulate in plants during a combination of drought and heat stress. Heat stress was found to ameliorate the toxicity of Pro to cells, suggesting that during a combination of drought and heat stress sucrose replaces Pro in plants as the major osmoprotectant. Our results highlight the plasticity of the plant genome and demonstrate its ability to respond to complex environmental conditions that occur in the field.