Cloning, Expression Analysis, and Functional Characterization of Candidate Oxalate Transporter Genes of HbOT1 and HbOT2 from Rubber Tree ( Hevea brasiliensis )

• Published in: Cells (Basel, Switzerland) Switzerland), 2022-11, Vol.11 (23), p.3793
• Main Authors: Yang, Zongming, Zhao, Pingjuan, Peng, Wentao, Liu, Zifan, Xie, Guishui, Ma, Xiaowei, An, Zewei, An, Feng
• Format: Article
• Language: English
• Subjects: Aluminum; Aluminum - metabolism; aluminum toxicity; Cloning; Detoxification; Fungi; Gene expression; Gene Expression Regulation, Plant; Genetic engineering; HbOT1; HbOT2; Heavy metals; Hevea - genetics; Hevea - metabolism; Hevea brasiliensis; Hydrophobicity; Latex; Ligands; Manganese; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; Oxalate transporter; Oxalates - metabolism; Oxalic acid; Plant Proteins - metabolism; Rubber; Rubber products; Secretion; SNAP receptors; Stress concentration; Toxicity; Trees
• ISSN: 2073-4409; 2073-4409
• DOI: 10.3390/cells11233793

Secretion of oxalic acid from roots is an important aluminum detoxification mechanism for many plants such as (rubber tree). However, the underlying molecular mechanism and oxalate transporter genes in plants have not yet been reported. In this study, the oxalate transporter candidate genes and from the rubber tree were cloned and preliminarily identified. It was found that had a full length of 1163 bp with CDS size of 792 bp, encoding 263 amino acids, and had a full length of 1647 bp with a CDS region length of 840 bp, encoding 279 amino acid residues. HbOT1 and HbOT2 were both stable hydrophobic proteins with transmembrane structure and SNARE_assoc domains, possibly belonging to the SNARE_assoc subfamily proteins of the SNARE superfamily. qRT-PCR assays revealed that and were constitutively expressed in different tissues, with highly expressed in roots, stems, barks, and latex, while was highly expressed in latex. In addition, the expressions of and were up-regulated in response to aluminum stress, and they were inducible by metals, such as copper and manganese. Heterologous expression of and in the yeast mutant AD12345678 enhanced the tolerance to oxalic acid and high concentration aluminum stress, which was closely correlated with the secretion of oxalic acid. This study is the first report on oxalate transporter genes in plants, which provides a theoretical reference for the study on the molecular mechanism of oxalic acid secretion to relieve aluminum toxicity and on aluminum-tolerance genetic engineering breeding.