Two Aquaporin Genes, GhPIP2;7 and GhTIP2;1, Positively Regulate the Tolerance of Upland Cotton to Salt and Osmotic Stresses

Anhui Guo; Jianfeng Hao; Ying Su; Bin Li; Nan Zhao; Meng Zhu; Yi Huang; Baoming Tian; Gongyao Shi; Jinping Hua

doi:10.3389/fpls.2021.780486

Two Aquaporin Genes, GhPIP2;7 and GhTIP2;1, Positively Regulate the Tolerance of Upland Cotton to Salt and Osmotic Stresses

Front Plant Sci. 2022 Feb 11:12:780486. doi: 10.3389/fpls.2021.780486. eCollection 2021.

Authors

Anhui Guo¹, Jianfeng Hao², Ying Su¹, Bin Li¹, Nan Zhao¹, Meng Zhu¹, Yi Huang³, Baoming Tian², Gongyao Shi², Jinping Hua¹

Affiliations

¹ Laboratory of Cotton Genetics, Genomics and Breeding, Beijing Key Laboratory of Crop Genetic Improvement, Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
² Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.
³ Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China.

Abstract

Aquaporins (AQPs) facilitate the transport of water and small molecules across intrinsic membranes and play a critical role in abiotic stresses. In this study, 111, 54, and 56 candidate AQP genes were identified in Gossypium hirsutum (AD₁), Gossypium arboreum (A₂), and Gossypium raimondii (D₅), respectively, and were further classified into five subfamilies, namely, plasma intrinsic protein (PIP), tonoplast intrinsic protein (TIP), nodulin 26-like intrinsic protein (NIP), small basic intrinsic protein (SIP), and uncategorized X intrinsic protein (XIP). Transcriptome analysis and quantitative real-time PCR (qRT-PCR) revealed some high-expression GhPIPs and GhTIPs (PIP and TIP genes in G. hirsutum, respectively) in drought and salt stresses. GhPIP2;7-silenced plants decreased in the chlorophyll content, superoxide dismutase (SOD) activity, and peroxidase (POD) activity comparing the mock control (empty-vector) under 400 mM NaCl treatment, which indicated a positive regulatory role of GhPIP2;7 in salt tolerance of cotton. The GhTIP2;1-silenced cotton plants were more sensitive to osmotic stress. GhTIP2;1-overexpressed plants exhibited less accumulation of H₂O₂ and malondialdehyde but higher proline content under osmotic stress. In summary, our study elucidates the positive regulatory roles of two GhAQPs (GhPIP2;7 and GhTIP2;1) in salt and osmotic stress responses, respectively, and provides a new gene resource for future research.

Keywords: Gossypium; aquaporin; gene family; osmotic stress; salt stress.