Abstract: Root-knot nematodes (RKN) are pathogens affecting soybean production worldwide. Rmi1 (Resistance to M. incognita 1) is an additive gene for M. incognita resistance identified in soybean cv. Forrest, which resides in a major QTL on Chromosome 10. It has been established that Rmi1 is associated with multiple polymorphisms in the promoter and sequences of genes encoding ?-1,4-endoglucancase (EG) and pectin methylesterase (PME1), both of which exhibit higher expression in susceptible than in Rmi1 resistant plants. EG expression is correlated with RKN feeding cell formation, indicating EG functions as a susceptibility factor for soybean resistance to M. incognita. Plants, including genetically modified and transgenic plants, cells and seeds thereof that lack expression or functional gene products of EG and/or PME1 are provided. Compositions and methods for reducing or removing EG and/or PME1 expression in plants are also described.

Abstract: Disclosed herein are novel methods and materials for selecting transgenic cells. Specifically exemplified herein are positive selection methods that involve conferring to cells the ability to metabolize certain compounds, preferably arabitol, ribitol, raffinose, sucrose, mannitol or combinations thereof. Accordingly, transformed cells can be selected by simply subjecting them to a medium containing such compounds. The subject invention alleviates the disadvantages and concerns of negative selection methods, such as the unnecessary killing of transformed cells and the dispersal of potentially harmful genes (e.g., antibiotic or herbicide resistant genes) into the environment. Furthermore, novel nucleotide sequences relating to the E. coli rtl operon and arabitol dehydrogenase gene, and amino acid sequences relating to the gene products thereof are disclosed.

Abstract: Disclosed herein are novel methods and materials for selecting transgenic cells. Specifically exemplified herein are positive selection methods that involve conferring to cells the ability to metabolize certain compounds, preferably arabitol, ribitol, raffinose, sucrose, mannitol or combinations thereof. Accordingly, transformed cells can be selected by simply subjecting them to a medium containing such compounds. The subject invention alleviates the disadvantages and concerns of negative selection methods, such as the unnecessary killing of transformed cells and the dispersal of potentially harmful genes (e.g., antibiotic or herbicide resistant genes) into the environment. Furthermore, novel nucleotide sequences relating to the E. coli rtl operon and arabitol dehydrogenase gene, and amino acid sequences relating to the gene products thereof are disclosed.