ULTRASTRUCTURE OF THE ENDODERMIS OF FIG ROOT-TIPS IN RESPONSE TO SALINITY

Treatment of Pig (Ficus carica L.) with 100 mM NaCl in the nutrient so lution for ten days resulted in ultrastructural changes of root tip en dodermis. In the endodermal cells of the salt-treated root tips many t ubular invaginations (average diameter 25 nm) into the vacuoles develo ped, whereas in the endodermis of the control root tips only very few invaginations occurred. The distribution of the tubules was sometimes nonuniform with clusters of large numbers of tubules occurring. The po ssible function of these structures in controlling transport of Na+ an d Cl- and further work necessary to test such a function is discussed.