The Absorption and Translocation of Sulfur in Red Kidney Bean

Phytoremediation of Cu-contaminated vineyard soils in Brazil: A compendium of Brazilian pot studies

Vineyard soils can be contaminated by copper (Cu) due to successive applications of fungicides and organic fertilizers. Soil remediation can be addressed by altering soil properties or selecting efficient Cu-extracting cover crops tolerant to Cu toxicity. Our objectives were to synthesize the Cu-extracting efficiency by plant species tested in Brazil, classify them according to Cu resistance to toxicity, and assess the effect of soil properties on attenuating Cu toxicity. We retrieved results from 41 species and cultivars, totaling 565 observations. Freshly added Cu varied between 50 and 600 mg Cu kg-1 of soil across studies. The partition of Cu removal between the above- and below-ground portions was scaled as a logistic variable to facilitate data synthesis. The data were analyzed using the Adaboost machine learning model. Model accuracy (predicted vs. actual values) reached R2  = 0.862 after relating species, cultivar, Cu addition, clay, SOM, pH, soil test P, and Cu as features to predict the logistic target variable. Tissue Cu concentration varied between 7 and 105 mg Cu kg-1 in the shoot and between 73 and 1340 mg Cu kg-1 in the roots. Among soil properties, organic matter and soil test Cu most influenced the accuracy of the model. Phaseolus vulgaris, Brassica juncea, Ricinus communis, Hordeum vulgare, Sorghum vulgare, Cajanus cajan, Solanum lycopersicum, and Crotolaria spectabilis were the most efficient Cu-extracting cover crops, as shown by positive values of the logistic variable (shoot removal > root removal). Those Cu-tolerant plants showed differential capacity to extract Cu in the long run.

Accumulation of phosphate, sulfate and sucrose by excised Phloem tissues

Excised petiolar vascular bundles and excised phloem tissues have been shown to take up phosphate, sulfate and sucrose by a true accumulation process and against high concentration ratios. Phosphate was accumulated principally as inorganic phosphate, and sucrose principally as sucrose. The rates of accumulation of the 3 solutes into the phloem-containing tissues were from 4 to 35 times higher than into comparable parenchyma tissue. It is suggested that this active accumulation mechanism plays an important role in the phenomenon of phloem transport.THE EXCISED VASCULAR, PHLOEM AND PARENCHYMA TISSUES SHOW AN AGING PHENOMENON: aerating the excised tissues for 18 hours prior to their use causes marked changes in the accumulatory behavior of the tissue. The data suggest that 1 phosphate accumulation system of low affinity but high capacity exists in fresh tissue, and that aging allows the development of a second, additional phosphate accumulation mechanism of high affinity and low capacity. A possible role in the control of phosphate movement is suggested.

Effect of Growth on Redistribution of Some Mineral Elements in Peppermint

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Circulation Patterns for Phosphorus, Sulfur and Calcium in the Bean Plant

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Absorption and Mobility of Foliar Applied Nutrients

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