The manuscript has been withdrawn by the authors after it was pointed out by the editor that it was already published elsewhere. The letter of retraction from the authors states: "Now that the earlier version of our paper has already been printed in the "J. Plant Studies" in its recent issue (Vol. 2, No. 1, 2013), we are writing to the Chief Editor of the PMBP to withdraw the article (DOI 10.1007/s12298-013-0163-9) before it is finally printed in the Journal in order that an undesirable duplication would be avoided and our professional ethics be upheld. On behalf of all the co-authors, I sincerely apologize for the inconvenience caused to you.