This study of the Arabidopsis thaliana nitrate transporter NRT1.6 indicated that nitrate is important for early embryo development. Functional analysis of cDNA-injected Xenopus laevis oocytes showed that NRT1.6 is a low-affinity nitrate transporter and does not transport dipeptides. RT-PCR, in situ hybridization, and b-glucuronidase reporter gene analysis showed that expression of NRT1.6 is onl...

We previously showed that trehalose-6-phosphate synthase 1 (TPS1), which catalyses the first step in trehalose synthesis, is essential for embryo maturation in Arabidopsis. The tps1 mutant embryos develop more slowly than wild type. Patterning in the tps1 embryos appears normal but they do not progress past the torpedo stage to cotyledon stage, which is when storage reserves start to accumulate...

ABA plays important roles in many aspects of seed development, including accumulation of storage compounds, acquisition of desiccation tolerance, induction of seed dormancy and suppression of precocious germination. Quantification of ABA in the F(1) and F(2) populations originated from crosses between the wild type and an ABA-deficient mutant aba2-2 demonstrated that ABA was synthesized in both...

Developmental senescence is a coordinated physiological process in plants and is critical for nutrient redistribution from senescing leaves to newly formed sink organs, including young leaves and developing seeds. Progress has been made concerning the genes involved and the regulatory networks controlling senescence. The resulting complex metabolome changes during senescence have not been inves...

The study of flower development has experienced great advances over the last 15 years. The most important landmark was the proposal of the ABC model in which three different functions of overlapping activities account for the development of the four rings of organs of the eudicot flower. Most interestingly, during recent years this simple and elegant model has been broadly accepted and is appli...

Genes transformed into plants are usually inherited in a regular Mendelian manner. There are, however, transformants in which the selectable trait fails to segregate as expected. Genetic analysis of the kanamycin-resistance (KanR) trait in >900 independent transformants of Arabidopsis revealed that 9% produced progeny families with an enormous deficiency of KanR individuals. Self-pollination of...

Nitrogen (N) remobilization from reserves to sinks is essential for seedling establishment and seed production. Cytosolic glutamine synthetase (GS1) is up-regulated during both seed germination and seed filling in plants. However, the specific roles of the individual GS1 isogenes with respect to N remobilization, early seedling vigour, and final seed productivity are not known. In this study, i...

Most soybean cultivars possess broad leaflets; however, a recessive allele on the Ln locus is known to cause the alteration of broad to narrow leaflets. The recessive allele ln has also been considered to increase the number of seeds per pod (NSP) and has the potential to improve yield. Recently, Gm-JAG1 (Glyma20g25000), a gene controlling Ln, has been shown to complement leaf shape and silique...

In this study, the physiological functions of fungal mannitol metabolism in the pathogenicity and protection against environmental stresses were investigated in the necrotrophic fungus Alternaria brassicicola. Mannitol metabolism was examined during infection of Brassica oleracea leaves by sequential HPLC quantification of the major soluble carbohydrates and expression analysis of genes encodin...