Premium
Rhizobium Nod factors induce increases in intracellular free calcium and extracellular calcium influxes in bean root hairs
Author(s) -
Cárdenas Luis,
Feijó José A.,
Kunkel Joseph G.,
Sánchez Federico,
HoldawayClarke Terena,
Hepler Peter K.,
Quinto Carmen
Publication year - 1999
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1999.00517.x
Subject(s) - extracellular , intracellular , root hair , calcium , calcium in biology , biophysics , cytosol , microbiology and biotechnology , biology , biochemistry , chemistry , organic chemistry , gene , enzyme
Summary Application of Nod factors to growing, responsive root hairs of the bean Phaseolus vulgaris induces marked changes in both the intracellular cytosolic free calcium (Ca 2+ ) and in the influx of extracellular [Ca 2+ ]. The intracellular [Ca 2+ ], which has been measured by ratiometric imaging in cells microinjected with fura‐2‐dextran (70 kDa), elevates within 5 min from approximately 400 n m to 1500 n m in localised zones in the root hair apex. Of particular note is the observation that the elevated regions of [Ca 2+ ] appear to shift position during short time intervals. Increases in and fluctuations of the intracellular [Ca 2+ ] are also observed in the perinuclear region after 10–15 min treatment with Nod factors. The extracellular Ca 2+ flux, detected with the non‐invasive, calcium specific vibrating electrode, is inwardly directed and also increases quickly in response to Nod factors from 13 pmol cm –2 s –1 to 28 pmol cm –2 s –1 . Chitin‐oligomers, which are structurally similar but biologically inactive when compared to the active Nod factors, fail to elicit changes in either intracellular or extracellular Ca 2+ . The similar timing and location of the intracellular elevations and the increased extracellular influx provide support for the idea that Ca 2+ participates in secretion and cell wall remodelling, which occur in anticipation of root hair deformation and curling.