In a medium mixing bowl combine flour, baking soda, baking powder, and salt; set aside.
In a separate mixing bowl combine sugar, zucchini, cooking oil, egg, lemon juice, and lemon zest. Stir to combine.
Add dry ingredients to zucchini mixture; stir just until combined.
Spoon batter into greased 8x4 inch loaf pan.
Bake at 350 degrees for 45 minutes or until toothpick inserted in center comes out clean.
Cool in pan on a wire rack 15 min, then remove from pan and cool completely.
Once cool, combine ingredients for glaze and drizzle over bread.