Inositol plays a role in membrane trafficking and signaling in addition to regulating cellular metabolism and controlling growth. In plants, the myo-inositol-1-phosphate is synthesized from glucose 6-phosphate in a reaction catalyzed by the enzyme myo-inositol-1-phosphate synthase (EC 5.5.1.4). Inositol can be converted into phytic acid (phytate), the most abundant form of phosphate in seeds. The path to phytate has been suggested to proceed via the sequential phosphorylation of inositol phosphates, and/or in part via phosphatidylinositol phosphate. Soybean [Glycine max (L.) Merrill] lines were produced using interfering RNA (RNAi) construct in order to silence the myo-inositol-1-phosphate (GmMIPS1) gene. We have observed an absence of seed development in lines in which the presence of GmMIPS1 transcripts was not detected. In addition, a drastic reduction of phytate (InsP₆) content was achieved in transgenic lines (up to 94.5%). Our results demonstrated an important correlation between GmMIPS1 gene expression and seed development.

This protocol describes a method for high-frequency recovery of transgenic soybean, bean and cotton plants, by combining resistance to the herbicide imazapyr as a selectable marker, multiple shoot induction from embryonic axes of mature seeds and biolistics techniques. This protocol involves the following stages: plasmid design, preparation of soybean, common bean and cotton apical meristems for bombardment, microparticle-coated DNA bombardment of apical meristems and in vitro culture and selection of transgenic plants. The average frequencies (the total number of fertile transgenic plants divided by the total number of bombarded embryonic axes) of producing germline transgenic soybean and bean and cotton plants using this protocol are 9, 2.7 and 0.55%, respectively. This protocol is suitable for studies of gene function as well as the production of transgenic cultivars carrying different traits for breeding programs. This protocol can be completed in 7-10 months.

Sclerotinia sclerotiorum causes rot in a broad range of crops including lettuce, soybean, dry bean and tomato. Pathogenesis of Sclerotinia has been associated with the copious production of oxalic acid. Enzymes capable of degrading oxalic acid have been utilized to produce transgenic resistant plants. Transgenic lettuce lines containing the decarboxylase gene ( oxdc ) isolated from a Flammulina sp. were produced by Agrobacterium ‐mediated transformation. Out of 80 regenerated plants, PCR analysis revealed the presence of the oxdc gene in 34 lines. Except for eight lines, the primary transformants transferred the foreign gene to the first generation in a Mendelian fashion. In a detached‐leaf assay inoculated with agar plugs of a 2‐day‐old S. sclerotiorum culture, two lines (P100 and P43) were symptomless, while line P57 showed a delay in symptom development when compared with a nontransgenic control line. RT‐PCR analysis carried out with the resistant lines showed the expression of oxdc gene transcripts.

The rep gene of Bean golden mosaic virus (BGMV) is essential for virus replication. A mutated rep gene with amino acid codon change in the putative nucleoside triphosphate (NTP) binding motif D262R was created. Phaseolus vulgaris transformation was achieved with a vector that contained the mutated rep and bar genes. A total of 17 initial (T₀) transformants were analyzed. One line (M1/4) showed tolerance to glufosinate ammonium and partial resistance to the virus, that is, disease incidence depended on inoculation level. The incidence of BGMV increased with the increasing number of viruliferous whiteflies per plant, both in the transgenic and in the control plants. However, the number of symptomless plants was significantly higher in the transgenic group. The line M1/4 was studied during several generations and presented stability in the transgene loci and virus resistance. Southern blot analysis with genomic DNA of eight generations led to an estimate of two copies of the rep gene integrated at the same locus. RT-PCR analysis revealed the presence of both bar and rep genes transcripts. The mutated REP protein was present in amounts detectable by Western blot analysis in transgenic plants.