1. Heat oven to 350°F. Generously spray 12-cup fluted tube cake pan with baking spray with flour. In small bowl, place blueberries. Remove 1 tablespoon dry cake mix; sprinkle over berries, and toss to coat. Set aside.
2. In large bowl, place remaining cake mix, cream cheese, lemon peel, poppy seed, water, 1/4 cup lemon juice and eggs. Beat with electric mixer on medium speed 2 minutes, scraping bowl occasionally. Stir in coated blueberries and any remaining dry cake mix. Pour into pan.
3. Bake 38 to 43 minutes or until toothpick inserted in center comes out clean. Remove from oven. Let stand 20 minutes; remove from pan to cooling rack. Cool completely, about 1 hour.
4. Transfer cake to serving platter. In small bowl, beat powdered sugar and 2 tablespoons lemon juice with spoon until smooth and spreadable. If too stiff to spread, add additional lemon juice, 1 teaspoon at a time. Spread over cake. Store loosely covered at room temperature.