Project description:The goal of this project was to develop a genomic resource for macadamia agriculture in Hawai?i through constructing a transcriptome of M. tetraphylla and testing for hybridity in University of Hawai?i at M?noa breeding material.
Project description:In this study, we present a first proteomic overview of macadamia nut using a label-free shotgun proteomic approach and prediction of their proteins with potential allergenic activity and cross-reactivity via an in silico analysis. The defense response proteins were the most abundant group of proteins and accounted for 24% of the total abundance. The vicilin-like macadamia antimicrobial peptides 2-3 (MiAMP2) was the most abundant protein. The cascading of amino acid and carbohydrate metabolic pathways in macadamia nut were constructed and proposed for the first time. The in silico analysis revealed seed storage proteins (conglutins and vicilins), rubber elongation factor proteins, phosphate binding proteins, and detoxifying methylglyoxalases among others as proteins with allergenic and cross-reactive potential. The label-free shotgun proteomics study revealed valuable insight into the genetic and biological makeup of macadamia nut and potential proteins with predictive allergenic activity and cross-reactivity. Integration of genomics with the proteomic data will be indispensable for future molecular characterization of macadamia including allergens.
Project description:Durum wheat (Triticum turgidum subsp. durum) is widely grown for pasta production, and more recently, is gaining additional interest due to its resilience to warm, dry climates and its use as an experimental model for wheat research. To enable further research into endosperm development and storage reserve synthesis, we generated a high-quality transcriptomics dataset from developing endosperms of durum variety Kronos, to complement the extensive mutant resources available for this variety. Endosperms were dissected from grains harvested at eight timepoints during grain development (6 to 30 days post anthesis (dpa)), then RNA sequencing was used to profile the transcriptome at each stage. The largest changes in gene expression profile were observed between the earlier timepoints, prior to 15 dpa. We detected a total of 29,925 genes that were significantly differentially expressed between at least two timepoints, and clustering analysis revealed nine distinct expression patterns. Overall, we provide a valuable resource for studying endosperm development in this increasingly important crop species.
Project description:Nitrogen availability in the soil is a major determinant of crop yield. While the application of fertilizer can substantially increase the yield on poor soils, it also causes nitrate pollution of water resources and high costs for farmers. Increasing the nitrogen use efficiency in crop plants is a necessary step to implement low input agricultural systems. We exploited the genetic diversity present in the world-wide Arabidopsis thaliana population to study adaptive growth patterns and changes in gene expression associated with chronic low nitrate stress, with the aim to identify biomarkers associated with good plant performance under low nitrate availability. Transcription and epigenetic factors were identified as important players in the adaptatiion to limited nitrogen in a global gene expression analysis using the Affymetrix ATH1 chip.
Project description:In plants, juvenile to adult phase transition is regulated by the sequential activity of two microRNAs: miR156 and miR172. A decline in miR156 and increase in miR172 abundance is associated with phase transition. There is very limited information on phase transition in economically important horticultural tree crops, which have a significantly long vegetative phase affecting fruit bearing. Here we profiled various molecular cues known to be involved in phase transition and flowering, including the microRNAs miR156 and miR172, in three horticultural tree crops avocado (Persea americana), mango (Mangifera indica) and macadamia (Macadamia integrifolia). We observed that miR156 expression decreases as these trees age and can potentially be used as a juvenility marker. Consistent with findings in annual plants, we also observed conserved regulation of the miR156-SPL3/4/5 regulatory module in these genetically distant tree crops, suggesting that this pathway may play a highly conserved role in vegetative identity. Meanwhile, the abundance of miR172 and its target AP2-like genes, as well as the accumulation level of SPL9 transcripts, were not related with plant age in these crops except in avocado where miR172 expression increased steadily. Finally, we demonstrate that various floral genes, including AP1 and SOC1 were upregulated in the reproductive phase and can be used as potential markers for the reproductive phase transition. Overall, this study provides an insight into the molecular associations of juvenility and phase transition in horticultural trees where crop breeding and improvement is encumbered by long juvenile phases.
