INVESTIGADORES
SANTA MARIA Guillermo Esteban
artículos
Título:
The regulation of zinc uptake in wheat plants.
Autor/es:
SANTA MARIA G.E.; COGLIATTI D
Revista:
PLANT SCIENCE
Editorial:
ELSEVIER IRELAND LTD
Referencias:
Lugar: Amsterdam; Año: 1998 vol. 137 p. 1 - 12
ISSN:
0168-9452
Resumen:
The control of net zinc-uptake rate can be a critical factor for plant survival and growth in heavy metal polluted environments. Here we report the results of an study on the regulation of net Zn-uptake in wheat plants (Triticumaestivum L.) grown in solution culture at supra optimum levels of Zn supply. As external Zn-concentration was increased, net Zn-uptake rate increased. The higher the external Zn-concentration the higher both Zn-influx and efflux, with Zn-efflux increasing more. However the relative increase in the outward flux of Zn was not enough to prevent the potential increase of Zn-concentration within plant tissues up to toxic levels. On the other hand, when the external Zn-concentration was changed to a higher or a lower level, the unidirectional Zn-influx changed almost instantaneously, while the net uptake rate of Zn changed slowly, towards the level exhibited by plants kept in the previous solution. These findings are consistent with the concept that regulation of Zn fluxes, at supra optimum levels of Zn supply, appear to be controlled primarily by Zn-efflux and not by short or long term regulation of Zn-influx.