Effect of copper on the activation of the acid phosphatase from the green algae Pseudokirchneriella subcapitata.

The in vitro activation effect of copper on the acid phosphatase of the green algae Pseudokirch- neriella subcapitata (formely Selenastrum capricor- nutum) under preincubation condition. Apparent Michaelis constant values of 1.21 and 0.37 mM, and activation energy values of 26.8 and 13.6 kJ mol -1 were determined in the absence and in the presence of 0.2 mM Cu2?, respectively. The dissociation constant value for Cu2? binding to the enzyme was determined to be 22.04 lM. The decrease of the apparent Michaelis constant (Km) and activation energy values in the presence of Cu2? correlates well with its activating effect on the acid phosphatase activity. This propriety could be used as a sensitive bioindicator for copper in environmental samples.

Microwave-assisted solvent extraction and analysis of shikimic acid from plant tissues.

A better method for determination of shikimate in plant tissues is needed to monitor exposure of plants to the herbicide glyphosate [N-(phosphonomethyl)glycine] and to screen the plant kingdom for high levels of this valuable phytochemical precursor to the pharmaceutical oseltamivir. A simple, rapid, and efficient method using microwave-assisted extraction (MWAE) with water as the extraction solvent was developed for the determination of shikimic acid in plant tissues. High performance liquid chromatography was used for the separation of shikimic acid, and chromatographic data were acquired using photodiode array detection. This MWAE technique was successful in recovering shikimic acid from a series of fortified plant tissues at more than 90% efficiency with an interference-free chromatogram. This allowed the use of lower amounts of reagents and organic solvents, reducing the use of toxic and/or hazardous chemicals, as compared to currently used methodologies. The method was used to determine the level of endogenous shikimic acid in several species of Brachiaria and sugarcane (Saccharum officinarum) and on B. decumbens and soybean (Glycine max) after treatment with glyphosate. The method was sensitive, rapid and reliable in all cases.

Alleles of organic acid transporter genes are highly correlated with wheat resistance to acidic soil in field conditions.

2016

Development of tahiti acid lime [Citrus latifolia (YU. Tanaka) Tanaka] budded trees in combination with different rootstocks.

2016

Microwave-assisted solvent extraction and analysis of shikimic acid from plant tissues.

2008