Cloning and Expression Analysis of the Cuticular Lipid Transporter Gene ZxABCG11 Responding to Abiotic Stresses

• 1、State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, P.R. China.

Abstract：The well-developed and thick surface cuticle is an effective barrier to restrict water loss and resist arid environments for xerophytes. Following its biosynthesis in epidermal cells, the cuticle, which is composed of wax and cutin, collectively termed cuticular lipids, was exported across the plasma membrane to the cell wall and further to extracellular matrix. In plants, ABCG11 gene encoding a plasma membrane-localized ATP-binding cassette transporter was suggested to play the most important and central role in the progress of cuticular lipids secretion, but plants used in these researches were mesophytes possessing thinner cuticle.In this study, we cloned and characterized ZxABCG11 in Zygophyllum xanthoxylum. The results showed that the full length of ZxABCG11 was 2416 bp, including ORF 2100 bp, which encoded 700 amino acids. The amino acid sequence contains ABC transporters characteristic motif, the nucleic acid binding domain, transmembrane domain composed of six hydrophobic alpha helixes and shared high similarity (73%-85%) with the identified ABCG11 of other plants. The quantitative real-time PCR analysis revealed that ZxABCG11 was preferentially expressed in young leaves. And salt treatment (50 mM NaCl), osmotic (-0.5 MPa) and heat (35 C) stresses significantly induced the expression of ZxABCG11 in short time (0.5-6 h after treatments). The transcript abundance of ZxABCG11 raised maximum amount under the dual stresses of osmotic and heat, which was 8 times compared to the control, indicating that ZxABCG11 transporter possibly plays an important role in response to different stress.

Keywords： Zygophyllum xanthoxylum ZxABCG11 gene expression stress resistance