ABSTRACT
BACKGROUND: To date, oil-rich plants are the main source of biodiesel products. Because concerns have been voiced about the impact of oil-crop cultivation on the price of food commodities, the interest in oil plants not used for food production and amenable to cultivation on non-agricultural land has soared. As a non-food, drought-resistant and oil-rich crop, Jatropha curcas L. fulfils many of the requirements for biofuel production. RESULTS: We have generated 13,249 expressed sequence tags (ESTs) from developing and germinating Jatropha seeds. This strategy allowed us to detect most known genes related to lipid synthesis and degradation. We have also identified ESTs coding for proteins that may be involved in the toxicity of Jatropha seeds. Another unexpected finding is the high number of ESTs containing transposable element-related sequences in the developing seed library (800) when contrasted with those found in the germinating seed library (80). CONCLUSIONS: The sequences generated in this work represent a considerable increase in the number of sequences deposited in public databases. These results can be used to produce genetically improved varieties of Jatropha with increased oil yields, different oil compositions and better agronomic characteristics.
Subject(s)
Jatropha/genetics , Plant Oils/analysis , DNA Transposable Elements , Databases, Nucleic Acid , Gene Expression Profiling , Germination , Jatropha/chemistry , Jatropha/metabolism , Plant Oils/metabolism , Seeds/chemistry , Seeds/genetics , Seeds/metabolism , Transcription, GeneticABSTRACT
The effect of temperature on the activity and structural stability of an acid phosphatase (EC 3.1.3.2.) purified from castor bean (Ricinus communis L.) seeds have been examined. The enzyme showed high activity at 45 degrees C using p-nitrophenylphosphate (p-NPP) as substrate. The activation energy for the catalyzed reaction was 55.2 kJ mol(-1) and the enzyme maintained 50% of its activity even after 30 min at 55 degrees C. Thermal inactivation studies showed an influence of pH in the loss of enzymatic activity at 60 degrees C. A noticeable protective effect from thermal inactivation was observed when the enzyme was preincubated, at 60 degrees C, with the reaction products inorganic phosphate-P (10 mM) and p-nitrophenol-p-NP(10 mM). Denaturation studies showed a relatively high transition temperature (Tm) value of 75 degrees C and an influence of the combination of Pi (10 mM) and p-NP (10 mM) was observed on the conformational behaviour of the macromolecule.
