Gene pyramiding for insect resistance
 The overall goal is to determine the best approach to deploy Bt-soybean-- not only does the spectrum of resistance to defoliating pests need to be broadened, a strategy must be in place to ensure that Bt does not lose its effectiveness against Bt.
  • We used SSR markers to develop near-isogenic soybean lines in which genes for insect resistance, found in a soybean plant introduction and tagged with SSR markers, were combined with a Bt transgene
  • One QTL has been identified that has a synergistic interaction with Bt
  • We hava made a fine-map around the resistant locus, and made a BAC library from the resistant genotype, with the eventual goal of cloning the QTL
Transgenic soybean
 As part of the United Soybean Board initiative, we continually
  • Work to improve engineering efficiency
  • Engineer with genes that can improve seed quality & crop value

Centromere biology
 There is need for a greater understanding of the functional components of plant centromeres. The ability to create centromeres at will open the door to the creation of plant artificial chromosomes.
  • We engineer corn and rice with BACs containing centromeric DNA sequences
  • We are now following up on the hypothesis that centromeric function is due to a changed chromatin state, induced by nearby transcription


Aluminum tolerance in alfalfa
 Dissolved aluminum in acid soils is one of the major factors that inhibit root growth, and hence crop yields around the world. The problem is particularly serious for forage crops, for which lime applications to raise soil pH are not economically feasible.
  • We used molecular markers, identified via tissue-culture-based assays, to enhance aluminum tolerance in alfalfa.
  • Aluminum tolerance is being enhanced further via transformation for production of citrate synthase
  • Additional work centers on engineering with root-specific constructs and crossing transgenic plants with plants known to possess molecular-marker-tagged resistance


Non-antibiotic selectable markers
 The availability of additional plant transformation selectable markers is limited. In particular, those markers that do not depend on antibiotic resistance are desirable, to the extent that they can improve transformation efficiency and help dispel unfounded fears against GMOs.
  • We now use ribitol to replace ampicillin resistance in gene-gun vectors
  • We are developing arabitol dehydrogenase from E. coli as a positive selection vector for plant transformation


Ornamental white clover
 Although white clover is used almost exclusively as a forage, various highly attractive mutants are known. When combined together, white clover also has potential as an ornamental species.
  • The genetic control of many traits is known; for others it is not
  • We are trying to determine the genetic control of those traits for which the genetics are currently unknown
  • See some results


Production of specialty carotenoids in soybean
 Several animals depend on naturally occuring carotenoids in their diet. These carotenoids can be important to animal health, but also contribute to animal products that are visually applealing to consumers. When raised in captivity, animals do not have access to their normal dietary carotenoids; consequently, these same carotenoids must be supplied in their diets. Yet, dietary supplementation with carotenoids does not come cheap, and can account for 15-25% of total feed costs. The most cost-economical way to incorporate these natural carotenoids back into the animal diets would be by producing them in the soybean used as feed for them.
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