Structural and Biochemical Changes in Salicylic-Acid-Treated Date Palm Roots Challenged with Fusarium oxysporum f. sp. albedinis
Figure 5
Histochemical localization of caffeic acid derivatives and flavonoids in date palm root tissues stained with Neu’s reagent under blue light (green yellow and bright orange, resp.). (a: ×20) Control roots (UU), caffeic acid derivatives were observed at sclerenchyma, endodermis, and vascular parenchyma cell walls; (b: ×40) inoculated roots (UI), a dark zone appeared in cells situated near the xylem vessels. (c: ×20) SA treated roots (TU); (d: ×40) SA treated and Fusarium oxysporum f. sp. albedinis-infected roots (TI); note the presence of flavonoids in the vascular-parenchyma cell walls near the xylem vessels. X: xylem vessels; Ph: phloem; En; endodermic cells; Pc: parenchyma cells; Sc: sclerenchyma cells.
