Property is being reset in play mode with custom editor

howdy?

I have a class: using UnityEngine; using System.Collections; using UnityArabicSupport;

 [ExecuteInEditMode]
 public class ArabicTextMesh : MonoBehaviour
 {
     [SerializeField]
     private string text;
     
     public string Text {
         get { return text; }
         set {
             text = value;
             if (value != null)
                 gameObject.GetComponent<TextMesh> ().text = ArabicFixer.Fix (text);
         }
     }
 }

and have custom editor for it:

 using UnityEngine;
 using UnityEditor;
 using System.Collections;
 using UnityArabicSupport;
 
 [CustomEditor(typeof(ArabicTextMesh))] 
 public class ArabicTextMeshEditor : Editor {
     private ArabicTextMesh _target;
  
     void OnEnable()    
     {
         _target = (ArabicTextMesh)target;
     }
     
     public override void OnInspectorGUI ()
     {
         _target.Text = EditorGUILayout.TextField("Text", _target.Text);
     }
 }

It shows ok on inspector, but every time I start playing, unity resets text value. It seems that text field is not being serialized. What's wrong with it? How to fix it?