Response of root tip Ca²⁺ flux of Buchloe dactyloides clonal fragments under heterogeneous NaCl stress

Clonal plants exhibit different phenotypic responses to habitat heterogeneity. Ca²⁺ net flux response of root tips to NaCl stress and resultant modification of physiological integration were studied by measuring Ca²⁺ net fluxes of older and younger ramet root tips of Buchloe dactyloides under different NaCl stress treatments using non-invasive micro-test technique. The results showed that NaCl stress increases outflow of Ca²⁺ via voltage-dependent calcium pumps in the plasma membrane. Ca²⁺ net fluxes of root tips were modified by physiological integration of NaCl stress signals between older and younger ramets. Physiological integration was modified by the Ca²⁺ signal of ramets in response to nutrient heterogeneity.