USDA ARS

5 ARTICLES PUBLISHED IN JoVE

Immunology and Infection

Propagation of Homalodisca coagulata virus-01 via Homalodisca vitripennis Cell Culture

Anna M. Biesbrock¹, Christopher M. Powell¹, Wayne B. Hunter², Blake R. Bextine¹

¹Department of Biology, University of Texas at Tyler, ²U. S. Horticultural Research Laboratory, USDA ARS

Here we present a protocol to propagate Homalodisca vitripennis cells and HoCV-1 in vitro. Medium was removed from HoCV-1 positive cultures and RNA extracted every 24 hr for 168 hr. Cell survivability was quantified by trypan blue staining. Whole virus particles were extracted post-infection. Extracted RNA was quantified by qRT-PCR.

Engineering

Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction

Bradley K. Fritz¹, W. Clint Hoffmann¹

¹Aerial Application Technology Research Unit, USDA ARS

We present protocols to be used in the measurement of spray droplet size from agricultural nozzles used in both aerial and ground based agrochemical applications. These methods presented were developed to provide consistent and repeatable droplet size data both inter- and intra-laboratory, when using laser diffraction systems.

Environment

Double-stranded RNA Oral Delivery Methods to Induce RNA Interference in Phloem and Plant-sap-feeding Hemipteran Insects

Saikat Kumar B. Ghosh¹, Wayne B. Hunter², Alexis L. Park¹, Dawn E. Gundersen-Rindal¹

¹Invasive Insect Biocontrol and Behavior Laboratory, Agricultural Research Service, United States Department of Agriculture, ²Horticultural Research Laboratory, Agricultural Research Service, United States Department of Agriculture

This article demonstrates novel techniques developed for oral delivery of double-stranded RNA (dsRNA) through the vascular tissues of plants for RNA interference (RNAi) in phloem sap feeding insects.

Environment

Improving Infrared Spectroscopy Characterization of Soil Organic Matter with Spectral Subtractions

Andrew J. Margenot¹, Sanjai J. Parikh², Francisco J. Calderón³

¹Department of Crop Sciences, University of Illinois Urbana-Champaign, ²Department of Land, Air and Water Resources, University of California Davis, ³Central Great Plains Resources Management Research, USDA ARS

SOM underlies many soil functions and processes, but its characterization by FTIR spectroscopy is often challenged by mineral interferences. The described method can increase the utility of SOM analysis by FTIR spectroscopy by subtracting mineral interferences in soil spectra using empirically obtained mineral reference spectra.

JoVE Journal

Exploring the Root Microbiome: Extracting Bacterial Community Data from the Soil, Rhizosphere, and Root Endosphere

Tuesday Simmons¹, Daniel F. Caddell¹, Siwen Deng¹, Devin Coleman-Derr^1,2

¹Department of Plant and Microbial Biology, University of California, Berkeley, ²Plant Gene Expression Center, USDA ARS

Here, we describe a protocol to obtain amplicon sequence data of soil, rhizosphere, and root endosphere microbiomes. This information can be used to investigate the composition and diversity of plant-associated microbial communities, and is suitable for the use with a wide range of plant species.