Brittle leaf disease induces an oxidative stress and decreases the expression of manganese-related genes in date palm (Phoenix dactylifera L.)

► Study of oxidative stress generated by brittle leaf disease in date palm. ► Expression analysis of manganese related genes. ► Affected leaves and roots were deficient in manganese comparing to healthy control tissue. ► Chlorophyll content decreased in affected leaves caused by the decrease of synthesis and degradation. ► MnSOD activity decreased in affected leaves and roots.