Cycloartane- and Lanostane-Type Triterpenoids from the Resin of AZ-2, a Byproduct of Guayule Rubber Production.

A total of 12 new cycloartane- and lanostane-type triterpenoids including 16-deoxyargentatin A (), 16-deoxyisoargentatin A (), 7-oxoisoargentatin A (), 24--argentatin H (), 24---anisoylargentatin C (), 24---cinnamoylargentatin C (), 16-dehydroargentatin C (), 16,17(20)-didehydroargentatin C (), isoargentatin C (), isoargentatin H (), 3--quisquagenin (), and isoquisquagenin () together with 10 known triterpenoids (-) were isolated from the resin of AZ-2 obtained as a byproduct of Bridgestone guayule rubber production. The structures of new triterpenoids - and argentatin H (), which has previously been characterized as its diacetate (), were elucidated by extensive analysis of their spectroscopic data and chemical conversions, and the known compounds - were identified by comparison of their spectroscopic data with those reported. Of these, , , and exhibited weak cytotoxic activity for several cancer cell lines.

Downregulation of a CYP74 Rubber Particle Protein Increases Natural Rubber Production in .

We report functional genomics studies of a CYP74 rubber particle protein from , commonly called guayule. Previously identified as an allene oxide synthase (AOS), this CYP74 constitutes the most abundant protein found in guayule rubber particles. Transgenic guayule lines with gene expression down-regulated by RNAi () exhibited strong phenotypes that included agricultural traits conducive to enhancing rubber yield.

Phenotypic changes and DNA methylation status in cryopreserved seeds of rye (Secale cereale L.).

Conserving genetic diversity is a major priority of the National Laboratory for Genetic Resources Preservation (NLGRP), operated by the U.S. Department of Agriculture, Agricultural Research Service.

Root traits contributing to plant productivity under drought.

Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length, and considerable root length density, especially at depths in soil with available water.

Development of DArT marker platforms and genetic diversity assessment of the U.S. collection of the new oilseed crop lesquerella and related species.

The advantages of using molecular markers in modern genebanks are well documented. They are commonly used to understand the distribution of genetic diversity in populations and among species which is crucial for efficient management and effective utilization of germplasm collections. We describe the development of two types of DArT molecular marker platforms for the new oilseed crop lesquerella (Physaria spp.

Impact of Lygus spp. (Hemiptera: Miridae) on damage, yield and quality of lesquerella (Physaria fendleri), a potential new oil-seed crop.

Lesquerella, Physaria fendleri (A. Gray) S. Watson, is a mustard native to the western United States and is currently being developed as a commercial source of valuable hydroxy fatty acids that can be used in a number of industrial applications, including biolubricants, biofuel additives, motor oils, resins, waxes, nylons, plastics, corrosion inhibitors, cosmetics, and coatings.

Evaluation of new Lesquerella and Physaria (Brassicaceae) oilseed germplasm.

The seed oil of Lesquerella and the closely related genus Physaria (Brassicaceae) is rich in hydroxy fatty acids (HFAs). HFAs and their derivatives are used to produce a variety of industrial products including lubricants, nylon-11, plastics, drying agents, protective coatings, surfactants, cosmetics, and pharmaceuticals. Lesquerella fendleri is being developed as a new crop for arid regions of the southwestern United States as an alternative source of HFAs.