Recent and Projected Increases in Atmospheric CO2 Concentration Can Enhance Gene Flow between Wild and Genetically Altered Rice (Oryza sativa)

• Published in: PloS one Vol. 7; no. 5; p. e37522
• Main Authors: Ziska, Lewis H, Gealy, David R, Tomecek, Martha B, Jackson, Aaron K, Black, Howard L, Fuller, Dorian Q
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 23.05.2012; Public Library of Science (PLoS)
• Subjects: 20th century; Agricultural ecosystems; Agriculture; agroecosystems; Atmosphere - analysis; Biological evolution; Biology; Bumpers, Dale L; Carbon dioxide; Carbon Dioxide - analysis; Carbon dioxide atmospheric concentrations; Carbon dioxide concentration; Carbon dioxide in the atmosphere; Crops; feral animals; Fisheries; Fitness; Flowering; Gene flow; Gene Flow - genetics; Gene transfer; Genes; Genetic modification; Genetically engineered microorganisms; Genetics, Population; Germplasm; Herbicide resistance; Herbicides; hybrids; Hypotheses; inflorescences; Laboratories; Oryza - genetics; Oryza - growth & development; Oryza longistaminata; Oryza sativa; outcrossing; Plants, Genetically Modified - genetics; Plants, Genetically Modified - growth & development; Progeny; Reproduction - genetics; Reproductive fitness; Rice; Solanum dulcamara; Solanum nigrum; Solanum tuberosum; Sorghum; Sorghum halepense; transgenic plants; United States > US; Arkansas; Maryland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0037522

Although recent and projected increases in atmospheric carbon dioxide can alter plant phenological development, these changes have not been quantified in terms of floral outcrossing rates or gene transfer. Could differential phenological development in response to rising CO 2 between genetically modified crops and wild, weedy relatives increase the spread of novel genes, potentially altering evolutionary fitness? Here we show that increasing CO 2 from an early 20 th century concentration (300 µmol mol −1) to current (400 µmol mol −1) and projected, mid-21 st century (600 µmol mol −1) values, enhanced the flow of genes from wild, weedy rice to the genetically altered, herbicide resistant, cultivated population, with outcrossing increasing from 0.22% to 0.71% from 300 to 600 µmol mol −1 . The increase in outcrossing and gene transfer was associated with differential increases in plant height, as well as greater tiller and panicle production in the wild, relative to the cultivated population. In addition, increasing CO 2 also resulted in a greater synchronicity in flowering times between the two populations. The observed changes reported here resulted in a subsequent increase in rice dedomestication and a greater number of weedy, herbicide-resistant hybrid progeny. Overall, these data suggest that differential phenological responses to rising atmospheric CO 2 could result in enhanced flow of novel genes and greater success of feral plant species in agroecosystems.