Molecular Cloning and Functional Analysis of <i>GmLACS2-3</i> Reveals Its Involvement in Cutin and Suberin Biosynthesis along with Abiotic Stress Tolerance

• Main Authors: Asma Ayaz, Haodong Huang, Minglü Zheng, Wajid Zaman, Donghai Li, Saddam Saqib, Huayan Zhao, Shiyou Lü
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: International Journal of Molecular Sciences
• Subjects: long-chain acyl-CoA synthetases; <i>Glycine max</i>; abiotic stresses; cutin; cuticular wax; suberin
• Online Access: https://www.mdpi.com/1422-0067/22/17/9175
• ISSN: 1661-6596; 1422-0067

Cutin and wax are the main precursors of the cuticle that covers the aerial parts of plants and provide protection against biotic and abiotic stresses. Long-chain acyl-CoA synthetases (<i>LACSs</i>) play diversified roles in the synthesis of cutin, wax, and triacylglycerol (TAG). Most of the information concerned with <i>LACS</i> functions is obtained from model plants, whereas the roles of <i>LACS</i> genes in <i>Glycine max</i> are less known. Here, we have identified 19 <i>LACS</i> genes in <i>Glycine max</i>, an important crop plant, and further focused our attention on 4 <i>LACS2</i> genes (named as <i>GmLACS2-1, 2, 3, 4</i>, respectively). These <i>GmLACS2</i> genes display different expression patterns in various organs and also show different responses to abiotic stresses, implying that these genes might play diversified functions during plant growth and against stresses. To further identify the role of <i>GmLACS2-3,</i> greatly induced by abiotic stresses, we transformed a construct containing its full length of coding sequence into <i>Arabidopsis</i>. The expression of <i>GmLACS2-3</i> in an <i>Arabidopsis atlacs2</i> mutant greatly suppressed its phenotype, suggesting it plays conserved roles with that of <i>AtLACS2</i>. The overexpression of <i>GmLACS2-3</i> in wild-type plants significantly increased the amounts of cutin and suberin but had little effect on wax amounts, indicating the specific role of <i>GmLACS2-3</i> in the synthesis of cutin and suberin. In addition, these <i>GmLACS2-3</i> overexpressing plants showed enhanced drought tolerance. Taken together, our study deepens our understanding of the functions of <i>LACS</i> genes in different plants and also provides a clue for cultivating crops with strong drought resistance.