BIOL 206 Study Guide - Midterm Guide: Root Nodule, Nutrient, Denitrification
Document Summary
Bio 206: how and why the soil solution is acidified and how this may improve plant nutrition. Cations often interact with negative charges on the surface of the clay; available only if released. Anions dissolve in soil water, and are readily available for absorption by root hairs. for soil to become acidified it becomes more hydrolyzed. Important in nutrition because the protons from plants bombard clay particles which increase the chance that cations get released in soil solution eventually get taken up by plant. Proton pumping: hydrogen bombards clay from root hairs to release k+ ca2+, Mg2+ etc from clay and can be absorbed by plant. Co2 and water react to form carbonic acid. Not strong acid, but strong enough so it dissociates and releases hydrogen in soil. Legumes can form symbioses with soil bacteria called rhizobia. The legume releases chemical signals that attracts rhizobia to roots. This triggers the transcription of bacterial nod genes, this synthesizes nod factos.
