Background: Obtaining dedifferentiated cells (callus) that can regenerate into whole plants is not always feasible for many plant species. Sugar beet is known to be recalcitrant for dedifferentiation and plant regeneration. These difficulties were major obstacles for obtaining transgenic sugar beets through an -mediated transformation procedure.
View Article and Find Full Text PDFGlycine betaine (GB) is an important osmoprotectant and synthesized by two-step oxidation of choline. Choline monooxygenase (CMO) catalyzes the first step of the pathway and is believed to be a rate limiting step for GB synthesis. Recent studies have shown the importance of choline-precursor supply for GB synthesis.
View Article and Find Full Text PDFLevan, a type of fructan, is an oligomer or polymer with mainly a β(2,6)-linked fructose chain attached to sucrose. We introduced two timothy genes, PpFT1 and PpFT2, coding for two homologous sucrose:fructan 6-fructosyltransferases into sugar beet. Sugar beet produces a high concentration of sucrose, a starting substrate in fructan synthesis, in the root.
View Article and Find Full Text PDFCreating transgenic plants is invaluable for the genetic analysis of sugar beet and will be increasingly important as sugar beet genomic technologies progress. A protocol for Agrobacterium-mediated transformation of sugar beet is described in this chapter. Our protocol is optimized for a sugar beet genotype that performs exceptionally well in tissue culture, including the steps of dedifferentiation, callus proliferation, and regeneration.
View Article and Find Full Text PDFMale gametogenesis in plants can be impaired by an incompatibility between nuclear and mitochondrial genomes, termed cytoplasmic male sterility (CMS). A sterilizing factor resides in mitochondria, whereas a nuclear factor, Restorer-of-fertility (Rf), restores male fertility. Although a majority of plant Rf genes are thought to encode a family of RNA-binding proteins called pentatrico-peptide repeat (PPR) proteins, we isolated a novel type of Rf from sugar beet.
View Article and Find Full Text PDFIt has been reported that glycinebetaine (betaine) is synthesized in response to abiotic stresses via a two-step oxidation of choline in which choline monooxygenase (CMO) and betaine aldehyde dehydrogenase (BADH) are involved. Here we show that significant amounts of betaine, > 20 micromol/gFW, accumulated in young leaves of Beta vulgaris even under normal growth conditions, whereas levels in old leaves, cotyledons, hypocotyls, and roots were low. Under the same conditions, CMO accumulates exclusively in old leaves and is difficult to be detected in young leaves.
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