Science Concentrates BIOTECHNOLOGY LAB SAFETY
CREDIT: ALINE KOCH/JUSTUS LIEBIG UNIVERSITY GIESSEN
U of Hawaii fine lowered by 40% The University of Hawaii has settled its case with the Hawaii Occupational Safety & Health Division regarding a laboratory explosion in March. The settlement reduces the number of violations from 15 to nine and the fine from $115,500 to $69,300. Postdoctoral researcher Thea Ekins-Coward, who worked on the university’s Manoa campus for the Hawaii Natural Energy Institute, lost one of her arms in the explosion. When the blast occurred, she was preparing a gas mixture of 55% hydrogen, 38% oxygen, and 7% carbon dioxide to feed to bacteria to produce biofuels and bioplastics. An electrostatic discharge likely ignited the mixture, according to an investigation report issued in July by the University of California Center for Laboratory Safety. The settlement agreement was signed on Oct. 6. It combines similar violations that were originally listed individually, including two regarding laboratory exits and, separately, four centering on an inadequate chemical hygiene plan. The reduction in the overall number of violations, which were assessed the maximum state penalty of $7,700 each, resulted in the reduced fine. The agreement also revised some wording in the violation descriptions. “The penalty reduction is in consideration of the employer’s prompt abatement of the cited hazards and efforts to prevent their recurrence,” the settlement agreement says. “The university is working diligently to address the remaining violations, further strengthen the culture of safety, and foster an environment where hazard recognition and risk assessment are the standard of care for all activities,” the university says in a statement.—JYLLIAN
KEMSLEY
Antifungal RNA spray protects barley plants Plant vascular system transports RNA to leaves to fight fungi A spray containing double-stranded RNA (dsRNA) molecules can inhibit the growth of a notorious fungal pest, according to a new study of barley plants (PLOS Pathog. 2016, DOI: 10.1371/journal.ppat.1005901). Such RNA sprays may provide an alternative strategy to traditional chemical pesticides and genetically modified crops for combating agricultural pests. Karl-Heinz Kogel of Justus Liebig University Giessen and colleagues created an RNA that turns off a gene in Fusarium graminearum, a pest of corn, wheat, and barley that reduces crop yields and produces toxins that can contaminate the food supply. Common weapons against this fungus include compounds that block CYP51 enzymes responsible for producing ergosterol, the essential cholesterol analog in fungus. Kogel’s team blocked ergosterol formation in fungi with a dsRNA that bound CYP51 gene transcripts. Simply spritzing barley leaves with the dsRNA reduced expression of the CYP51 gene by about 50%. “We were expecting that the dsRNA would be immediately taken up by the fungus at the plant surface,” Kogel says. But when they examined the plants, they saw that the plant absorbed the dsRNA into its vasculature and transported it to the ends of the leaves. There the fungus grabbed the dsRNA from the leaf and used its own cellular machinery to process the long dsRNA into shorter RNA strands that then silenced the enzyme gene. “This is unexpected, and might make RNA sprays even more efficient than we thought,” because the plant vasculature could distribute the RNA throughout the plant’s tissues, Kogel says.
Fluorescently labeled dsRNA (green) accumulates in a barley plant’s vascular system (boundaries in red). “Every time we turn around, we find a paper that shows that dsRNA goes outside the boundaries that we previously thought it had,” says geneticist Jack Heinemann of the University of Canterbury. Kim Hammond-Kosack of Rothamsted Research, an agricultural research institute in England, says dsRNA fungicides may prove advantageous if they can simultaneously target multiple genes essential for fungal survival. But such sprays also have disadvantages, including a potentially higher cost and the inability to affect fungi that lack RNA-processing machinery. There is also a risk that mutations in the RNA-processing machinery of pathogens could lead to a wider resistance of dsRNA fungicides.—RYAN CROSS
OVERHEARD
“Chemists are solving mysteries all the
time, whether it be in the chemistry lab or in the FBI lab.” —Michael McGinnis, chair of the American Chemical Society’s Committee on Community Activities. The committee organizes National Chemistry Week, which takes place Oct. 16–22. To celebrate this year’s theme, “Solving Mysteries through Chemistry,” more than 160 ACS local sections are planning outreach events around the U.S. OCTOBER 17, 2016 | CEN.ACS.ORG | C&EN
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