https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44664 Wed 24 May 2023 10:47:49 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:22036 Wed 11 Apr 2018 17:01:12 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20431 Sat 24 Mar 2018 08:03:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:22243 Vigna unguiculata ssp. sesquipedialis) differing in pod wall and seed growth rates. Pod growth dominates over seed growth in genotype ‘Zhijiang 121’ but not in ‘Zhijiang 282’ in which a ‘bulging pod’ phenotype is apparent from 8 d post-anthesis (dpa) onward. Methods: Seed and pod wall growth rates and degree of pod-bulging were measured in the two genotypes together with assays of activities of sucrose-degrading enzymes and sugar content in pod wall and seed and evaluation of cellular pathways of phloem unloading in seed coat using a symplasmic fluorescent dye, 5(6)-carboxyfluorescein (CF). Key Results: Activities of cell wall, cytoplasmic and vacuolar invertases (CWIN, CIN and VIN) were significantly smaller in pod walls of ‘282’ than in ‘121’ at 10 dpa onwards. Low INV activities were associated with weak pod wall growth of ‘282’. In seed coats, CF was confined within the vasculature in ‘282’ but moved beyond the vasculature in ‘121’, indicating apoplasmic and symplasmic phloem unloading, respectively. Higher CWIN activity in ‘282’ seed coats at 6–8 dpa correlated with high hexose concentration in embryos and enhanced early seed growth. However, CWIN activity in ‘282’ decreased significantly compared with ‘121’ from 10 dpa onwards, coinciding with earlier commencement of nuclei endoreduplication in their embryos. Conclusions: The study shows genotypic differences between ‘bulging pod’ and ‘non-bulging’ phenotypes of asparagus bean in sucrose metabolism in relation to the pathway of phloem unloading in developing seed coats, and to pod and seed growth. Low INV activity in pod wall corresponds to its shortened and weak growth period; by contrast, the apoplasmic path in the seed coat is associated with high CWIN activity and strong early seed growth.]]> Sat 24 Mar 2018 07:17:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35063 Malus domestica) carbohydrate metabolism, we cloned the coding sequences of MdFRK1 and MdFRK2 from the ‘Royal Gala’ apple. The results showed that MdFRK2 expression was extremely high in shoot tips and young fruit. Analyses of heterologously expressed proteins revealed that MdFRK2 had a higher affinity for fructose than did MdFRK1, with Km values of 0.1 and 0.62 mM for MdFRK2 and MdFRK1, respectively. The two proteins, however, exhibited similar Vmax values when their activities were significantly inhibited by high concentrations of fructose. MdFRK2 ectopic expression was associated with a general decrease in fructose concentration in transgenic lines. In leaves, increased FRK activity similarly resulted in reduced concentrations of glucose and sucrose but no alterations in sorbitol concentration. When compared with those in the untransformed control, genes involved in sorbitol synthesis (A6PR) and the degradation pathway (SDH1/2) were significantly upregulated in transgenic lines, whereas those involved in sucrose synthesis (SPS1) and other degradation processes (SUSY4, NINV1/2, and HxK2) were downregulated. The activity of enzymes participating in carbohydrate metabolism was proportional to the level of gene expression. However, the growth performance and photosynthetic efficiency did not differ between the transgenic and wild-type plants. These results provide new genetic evidence to support the view that FRK plays roles in regulating sugar and sorbitol metabolism in Rosaceae plants.]]> Mon 17 Jun 2019 12:58:51 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39209 Arabidopsis epidermal peel were detected with or without exogenous application of mannose, fructose, glucose, and glucose-6-phosphate (G-6P). The results here showed that G-6P, but not glucose itself, induces stomatal closure in Arabidopsis. Furthermore, detection of stomatal apertures of Arabidopsis hexokinase loss of function with exogenous application of glucose showed that glucose induced stomatal closure was not due to osmotic pressure and it triggered guard cell ROS production depend on hexokinase activity. The effect of irradiance and G-6P on regulation of Arabidopsis stomatal aperture was investigated. The data obtained here indicated that G-6P induced changes of stomatal aperture depend on irradiance.]]> Fri 27 May 2022 10:20:29 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:49412 Fri 12 May 2023 14:55:20 AEST ]]>