https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18038 Wed 11 Apr 2018 09:22:16 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:30715 Pongamia pinnata and the model legume Medicago truncatula store considerable oil, apart from protein, in their cotyledons. However, as a group, legume storage strategies are quite variable and provide opportunities for better understanding of carbon partitioning into different storage products. Legumes with their ability to fix nitrogen can also increase the sustainability of agricultural systems. This review integrates the cell biology, biochemistry and molecular biology of oil body biogenesis before considering biotechnology strategies to enhance oil body biosynthesis. Cellular aspects of packaging triacylglycerol (TAG) into oil bodies are emphasized. Enhancing seed oil content has successfully focused on the up-regulation of the TAG biosynthesis pathways using overexpression of enzymes such as diacylglycerol acyltransferase1 and transcription factors such as WRINKLE1 and LEAFY COTYLEDON1. While these strategies are central, decreasing carbon flow into other storage products and maximizing the packaging of oil bodies into the cytoplasm are other strategies that need further examination. Overall there is much potential for integrating carbon partitioning, up-regulation of fatty acid and TAG synthesis and oil body packaging, for enhancing oil levels. In addition to the potential for integrated strategies to improving oil yields, the capacity to modify fatty acid composition and use of oil bodies as platforms for the production of recombinant proteins in seed of transgenic legumes provide other opportunities for legume biotechnology.]]> Thu 21 Oct 2021 12:53:03 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:45692 EgENOD₉₃ expression is essential for somatic embryogenesis. Abstract: Micropropagation of oil palm through tissue culture is vital for the generation of superior and uniform elite planting materials. Studies were carried out to identify genes to distinguish between leaf explants with the potential to develop into embryogenic or non-embryogenic callus. Oil palm cDNA microarrays were co-hybridized with cDNA probes of reference tissue, separately with embryo forming (media T527) and non-embryo (media T694) forming leaf explants sampled at Day 7, Day 14 and Day 21. Analysis of the normalized datasets has identified 77, 115 and 127 significantly differentially expressed genes at Day 7, Day 14, and Day 21, respectively. An early nodulin 93 protein gene (ENOD₉₃), was highly expressed at Day 7, Day 14, and Day 21 and in callus (media T527), as assessed by RT-qPCR. Validation of EgENOD₉₃ across tissue culture lines of different genetic background and media composition showed the potential of this gene as an embryogenic marker. In situ RNA hybridization and functional characterization in Medicago truncatula provided additional evidence that ENOD₉₃ is essential for somatic embryogenesis. This study supports the suitability of EgENOD₉₃ as a marker to predict the potential of leaf explants to produce embryogenic callus. Crosstalk among stresses, auxin, and Nod-factor like signalling molecules likely induces the expression of EgENOD₉₃ for embryogenic callus formation.]]> Thu 03 Nov 2022 10:03:56 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:1182 Sat 24 Mar 2018 08:28:26 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34114 Allium cepa) bulbs to accumulate anthocyanin were quantified by both absorbance ratios and fluorescence. We observed that water-stressing excised leaf segments induced anthocyanin formation, and fluorescence indicated that this anthocyanin was spectrally similar to the anthocyanin in the outer epidermal cells. This environmental induction may require a signal emanating from the leaf mesophyll, as induction did not occur in detached epidermal peels. Exogenous transcription factors that successfully drive anthocyanin biosynthesis in other species were also tested through transient gene expression using particle bombardment. Although the petunia R2R3-MYB factor AN2 induced anthocyanin in both excised leaves and epidermal peels, several transcription factors including maize C1 and Lc inhibited normal anthocyanin development in excised leaves. This inhibition may be due to moderate levels of conservation between the exogenous transcription factors and endogenous Allium transcription factors. The over-expressed exogenous transcription factors cannot drive anthocyanin biosynthesis themselves, but bind to the endogenous transcription factors and prevent them from driving anthocyanin biosynthesis.]]> Mon 11 Feb 2019 16:05:10 AEDT ]]>