title: When defense pathways collide. The response of Arabidopsis to a combination of drought and heat stress.
abstract: 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 glucose. 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.
authors.affiliation: Department of Biology, Technion, Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Rizhsky
authors.forename: Hongjian
authors.initials: H
authors.lastname: Liang
authors.forename: Joel
authors.initials: J
authors.lastname: Shuman
authors.forename: Vladimir
authors.initials: V
authors.lastname: Shulaev
authors.forename: Sholpan
authors.initials: S
authors.lastname: Davletova
authors.forename: Ron
authors.initials: R
authors.lastname: Mittler
mesh_terms: D000064:Acclimatization / Q000235:genetics* / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D050260:Carbohydrate Metabolism; D004190:Disasters; D018506:Gene Expression Regulation, Plant; D005947:Glucose / Q000378:metabolism; D006358:Hot Temperature; D008320:Maltose / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D013395:Sucrose; D008320:Maltose; D011392:Proline; D005947:Glucose