Journal Article

Transgeneration memory of stress in plants

Zipfel, C, Molinier, J, Ries, G, Hohn, B

2006

Overview

Leafy Legacy Plants can't run from unpleasantness such as too much or too little heat or light. Instead they show varying degrees of tolerance by reacting to stress with a range of physiological responses. Surprisingly, when Arabidopsis thaliana plants are exposed to stress (UV light or a chemical mimicking pathogenic attack), changes are seen not only in the treated plants but also in several generations of their untreated offspring. The plants 'remember' the stress, presumably using an as-yet unknown epigenetic mechanism. Echoes, but only echoes, of the discredited lamarckian idea of chromosomal inheritance of acquired traits. Plants exposed to environmental stresses such as ultraviolet light exhibit increased recombination between homologous chromosomes. Here, the progeny of plants that were exposed to an environmental stress also exhibited increased levels of genetic recombination, even though the progeny were not actually exposed to the stress. Owing to their sessile nature, plants are constantly exposed to a multitude of environmental stresses to which they react with a battery of responses. The result is plant tolerance to conditions such as excessive or inadequate light, water, salt and temperature, and resistance to pathogens. Not only is plant physiology known to change under abiotic or biotic stress, but changes in the genome have also been identified 1 , 2 , 3 , 4 , 5 . However, it was not determined whether plants from successive generations of the original, stressed plants inherited the capacity for genomic change. Here we show that in Arabidopsis thaliana plants treated with short-wavelength radiation (ultraviolet-C) or flagellin (an elicitor of plant defences 6 ), somatic homologous recombination of a transgenic reporter is increased in the treated population and these increased levels of homologous recombination persist in the subsequent, untreated generations. The epigenetic trait of enhanced homologous recombination could be transmitted through both the maternal and the paternal crossing partner, and proved to be dominant. The increase of the hyper-recombination state in generations subsequent to the treated generation was independent of the presence of the transgenic allele (the recombination substrate under consideration) in the treated plant. We conclude that environmental factors lead to increased genomic flexibility even in successive, untreated generations, and may increase the potential for adaptation.

• Publisher: Nature Publishing Group UK,Nature Publishing,Nature Publishing Group
• Subject: Acclimatization - drug effects / Acclimatization - radiation effects / Adaptation to environment and cultivation conditions / Agronomy. Soil science and plant productions / Alleles / Arabidopsis - drug effects / Arabidopsis - genetics / Arabidopsis - physiology / Arabidopsis - radiation effects / Arabidopsis thaliana / bacterial proteins / Biological and medical sciences / Botany / Crosses, Genetic / Environmental factors / Environmental stress / Epigenesis, Genetic / epigenetics / Evolutionary biology / flagellin / Flagellin - pharmacology / Flexibility / Fundamental and applied biological sciences. Psychology / Genetic recombination / Genetics and breeding of economic plants / Genomics / homologous recombination / Humanities and Social Sciences / hyper-recombination / irradiation / letter / Light / multidisciplinary / Pathogens / Physiology / plant pathogenic bacteria / Plant physiology / plant stress / Plants, Genetically Modified / Pollen - physiology / Radiation / Recombination, Genetic - drug effects / Recombination, Genetic - genetics / Recombination, Genetic - physiology / Recombination, Genetic - radiation effects / resistance mechanisms / Science / Science (multidisciplinary) / somatic homologous recombination / Stress / Transgenes - genetics / ultraviolet radiation / Ultraviolet Rays / Varietal selection. Specialized plant breeding, plant breeding aims