Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 5/2/2002
Publication Date: 2/14/2002
Citation: PINEROS, M.A., KOCHIAN, L.V. H+ CURRENTS AROUND PLANT ROOTS. BOOK CHAPTER. 2002. p. 299-322. Interpretive Summary:
Technical Abstract: It has long been known that roots can dramatically alter the chemical make up of their rhizosphere environment. One of the most important ways this is accomplished is via changes in rhizosphere pH that are mediated by root H+ transport processes. These transport processes include H+ extrusion via the plasma membrane H+ ATPase, and H+ influx via coupled solute transport systems. It has also been well documented that roots generate electric fields that are the product of ionic currents traversing root-cell membranes. Research conducted at the intersection of electrical fields and root ion transport processes has indicated that H+ fluxes comprise a significant fraction of the ion currents that are the driving force for root-associated electric fields. This chapter summarizes the progress in characterizing and understanding these ionic currents surrounding roots. There is considerable circumstantial evidence in the literature implicating gthese H+ currents and their associated electrical fields in a number of root functions, including growth and development, gravitropism, root responses to abiotic and biotic stress, and mineral acquisition. However, the underlying mechanisms that link H+ currents to these various root functions and processes still remain to be elucidated. A better understanding of the roles for these electrical phenomena and H+ currents in root function will go a long ways towards helping researchers understand how roots respond to their soil environment, and facilitate changes in root-associated processes that allow plants to positively interact with the environment.