Project description:Aluminum (Al) toxicity is an important restraint to soybean (Glycine max L. Merr.) production on acid soils. However, little is known about the genes underlying Al tolerance in soybean. We used microarrays to detail the global programme of gene expression under control and Al stress in two soybean at 6, 12, and 24 h.
Project description:Gene expression profiling in soybean under aluminum stress: genes differentially expressed between Al-tolerant and Al-sensitive genotypes. Aluminum toxicity is the most important constraint of crop production on acid soils. Understanding the molecular and genetic mechanisms of tolerance is crucial for developing efficient breeding programs to improve Al tolerance. This research was undertaken to identify candidate Al-tolerance genes in soybean. Two soybean genotypes PI 416937 (Al-tolerant) and Young (Al-sensitive) seedlings were exposed to zero or 10 µM Al in a growth chamber under hydroponic conditions for four time spans of 2, 12, 48 or 72 hrs. Microarray analysis was made on mRNA isolated from 1 cm long tap root tips using an Affymetrix soybean genome array. Both novel and previously reported aluminum-responsive genes were identified. The differentially expressed genes were enriched for metabolism, stress response and transporters. Multiple putative Al-tolerance genes uniquely induced in the tolerant genotype includes the up-regulation of previously identified transcription factors auxin down regulated-like protein (ADR6-like) and basic leucine zipper (bZIP 94), sulfur transmembrane transport protein and lipid transfer protein (Sec 14 ) and novel genes that include rare cold inducible protein (RCI2B ), GPI-transamidase, malonyl-COA: Isoflavone 7-O-glucoside-6˝-O-malontransferase, a cell proliferation protein (WPP2), Oleosin protein, pectinestrease inhibitor, and impaired sucrose induction1. The genes identified in this study will be utilized as important genetic resources for future improvement of Al tolerance in soybean. Key words: Soybean, Al tolerance, gene expression, microarray
Project description:Bone defects arising from fractures or disease represent a significant problem for surgeons to manage and are a substantial economic burden on the healthcare economy. Recent advances in the development of biomaterial substitutes provides an attractive alternative to the current “gold standard” autologous bone grafting. Despite on-going research, we are yet to identify cost effective biocompatible, osteo-inductive factors that stimulate controlled, accelerated bone regeneration.We have recently reported that enzymes with peroxidase activity possess previously unrecognised roles in extracellular matrix biosynthesis, angiogenesis and osteoclastogenesis, which are essential processes in bone remodelling and repair. Here, we report for the first time, that plant-derived soybean peroxidase (SBP) possesses pro-osteogenic ability by promoting collagen I biosynthesis and matrix mineralization of human osteoblasts in vitro. Mechanistically, SBP regulates osteogenic genes responsible for inflammation, extracellular matrix remodelling and ossification, which are necessary for normal bone healing. Furthermore, SBP was shown to have osteo-inductive properties, that when combined with commercially available biphasic calcium phosphate (BCP) granules can accelerate bone repair in a critical size long bone defect ovine model. Micro-CT analysis showed that SBP when combined with commercially available biphasic calcium phosphate (BCP) granules significantly increased bone formation within the defects as early as 4 weeks compared to BCP alone. Histomorphometric assessment demonstrated accelerated bone formation prominent at the defect margins and surrounding individual BCP granules, with evidence of intramembranous ossification. These results highlight the capacity of SBP to be an effective regulator of osteoblastic function and may be beneficial as a new and cost effective osteo-inductive agent to accelerate repair of large bone defects.
Project description:Gene expression profiling in soybean under aluminum stress: genes differentially expressed between Al-tolerant and Al-sensitive genotypes. Aluminum toxicity is the most important constraint of crop production on acid soils. Understanding the molecular and genetic mechanisms of tolerance is crucial for developing efficient breeding programs to improve Al tolerance. This research was undertaken to identify candidate Al-tolerance genes in soybean. Two soybean genotypes PI 416937 (Al-tolerant) and Young (Al-sensitive) seedlings were exposed to zero or 10 µM Al in a growth chamber under hydroponic conditions for four time spans of 2, 12, 48 or 72 hrs. Microarray analysis was made on mRNA isolated from 1 cm long tap root tips using an Affymetrix soybean genome array. Both novel and previously reported aluminum-responsive genes were identified. The differentially expressed genes were enriched for metabolism, stress response and transporters. Multiple putative Al-tolerance genes uniquely induced in the tolerant genotype includes the up-regulation of previously identified transcription factors auxin down regulated-like protein (ADR6-like) and basic leucine zipper (bZIP 94), sulfur transmembrane transport protein and lipid transfer protein (Sec 14 ) and novel genes that include rare cold inducible protein (RCI2B ), GPI-transamidase, malonyl-COA: Isoflavone 7-O-glucoside-6˝-O-malontransferase, a cell proliferation protein (WPP2), Oleosin protein, pectinestrease inhibitor, and impaired sucrose induction1. The genes identified in this study will be utilized as important genetic resources for future improvement of Al tolerance in soybean. Key words: Soybean, Al tolerance, gene expression, microarray Two genotypes: PI 416937 (p) and Young (y); two treatments: aluminum or untreated; four time points: 2, 12, 48, and 72 hrs; 2 or 3 replicates.
Project description:Gene expression profiling in soybean under aluminum stress: Transcriptome response to Al stress in roots of Al-tolerant genotype (PI 416937). Aluminum (Al) toxicity is a major constraint of crop production on acid soils. Many commercial soybean cultivars and advanced breeding lines have been evaluated for Al tolerance. Aluminum tolerance is quantitatively inherited trait in soybean making it difficult for genetic improvement. Understanding the molecular and genetic mechanisms of tolerance is crucial for developing efficient and effective programs aimed at improving Al tolerance trait The molecular mechanisms of Al tolerance is poorly understood in soybean. The objective of the research was to identify candidate aluminum tolerance genes in soybean Al-tolerant soybean genotype PI 416937 seedlings were exposed to zero or 10 µM Al in growth chamber under hydroponic conditions for four time span of 2, 12, 48 and 72 hrs in a randomized complete block design with three replications. Microarray analysis was made on mRNA isolated from 1 cm log tap root tips using Affymetrix soybean array with over 68,000 probe sets Glycine max L and wild soybean combined. Both novel and known genes were discovered in response to Al treatment. They include Al tolerance relevant proteins, families of transcription factors, zinc finger, bZIP, WRKY, MYB, ADR6, and NAC domain proteins were induced likely regulating Al tolerance downstream genes. Stress related proteins, cytochrome P450, glutathione-s transferase, glutaredoxin family and ascorbic acid biosynthesis protein were induced as signatures of cellular detoxification mechanisms. An ABC type multidrug resistance protein that could act as citrate transporter or Al exporter was up-regulated, a key Al tolerance mechanisms in several species. A cell wall loosening enzyme endoxylglucan hydrolases were also up-regulated probably reversing the wall rigidification caused by Al and promoting root growth under Al stress. Phytosulfokines growth factor involved in cell division and proliferation was up-regulated likely as a direct counter action to Al toxicity which inhibits root growth by limiting cell division and elongation. In conclusion, the Al tolerance candidate genes identified herein are potential targets for future genetic engineering and molecular breeding work on Al tolerance trait in soybean which in turn would contribute to gain in soybean productivity on acid soils.
Project description:Aluminum (Al) toxicity is a major factor limiting crop yields on acid soils. In maize, Al tolerance is a complex phenomenon involving multiple genes and physiological mechanisms yet uncharacterized. To begin elucidating the molecular basis of maize Al toxicity and tolerance, we performed a detailed temporal analysis of root gene expression under Al stress using microarrays with an Al-tolerant and an Al-sensitive maize genotype. Seedlings of both genotypes were grown in hydroponics in a full nutrient solution containing 39uM of free Al3+ activity. Root samples were collected at 'time zero', and after 2, 6 and 24 hours of treatment. Keywords: stress treatment, time course