Reduce Draw call for Multiple GUI Textures with same Texture

I have multiple GUI Textures with same texture in my game. It results large number of DrawCalls . How to reduce DrawCalls using common textures ?

Example code

using UnityEngine;
using System.Collections;
public class Example : MonoBehaviour 

  public GUISkin MyGUISkin;

  void OnGUI()


      GUI.Box ( new Rect ( Screen.width*0.1f,Screen.height*0.12f,Screen.width*0.49f,Screen.height * 0.58f),"",MyGUISkin.customStyles[1]);

      GUI.Box ( new Rect ( Screen.width*0.1f,Screen.height*0.22f,Screen.width *0.49f,Screen.height * 0.58f),"",MyGUISkin.customStyles[1]);



You can’t do that with OnGUI code. You’ll have to use something else, like a third-party GUI system.