Overexpression of OsTIP1;2 confers arsenite tolerance in rice and reduces root-to-shoot translocation of arsenic

Suhas Balasaheb Karle; Yogesh Negi; Sudhakar Srivastava; Penna Suprasanna; Kundan Kumar

doi:10.1016/j.plaphy.2024.108608

Overexpression of OsTIP1;2 confers arsenite tolerance in rice and reduces root-to-shoot translocation of arsenic

Plant Physiol Biochem. 2024 Apr 9:210:108608. doi: 10.1016/j.plaphy.2024.108608. Online ahead of print.

Authors

Suhas Balasaheb Karle¹, Yogesh Negi¹, Sudhakar Srivastava², Penna Suprasanna³, Kundan Kumar⁴

Affiliations

¹ Department of Biological Sciences, Birla Institute of Technology and Science Pilani, K. K. Birla Goa Campus, Goa, 403726, India.
² Plant Stress Biology Laboratory, Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India.
³ Amity Institute of Biotechnology, Amity University Maharashtra, Mumbai, 410206, India.
⁴ Department of Biological Sciences, Birla Institute of Technology and Science Pilani, K. K. Birla Goa Campus, Goa, 403726, India. Electronic address: kundan@goa.bits-pilani.ac.in.

PMID: 38615445
DOI: 10.1016/j.plaphy.2024.108608

Abstract

Tonoplast Intrinsic Proteins (TIPs) are vital in transporting water and solutes across vacuolar membrane. The role of TIPs in the arsenic stress response is largely undefined. Rice shows sensitivity to the arsenite [As[III]] stress and its accumulation at high concentrations in grains poses severe health hazards. In this study, functional characterization of OsTIP1;2 from Oryza sativa indica cultivar Pusa Basmati-1 (PB-1) was done under the As[III] stress. Overexpression of OsTIP1;2 in PB-1 rice conferred tolerance to As[III] treatment measured in terms of enhanced shoot growth, biomass, and shoot/root ratio of overexpression (OE) lines compared to the wild-type (WT) plants. Moreover, seed priming with the IRW100 yeast cells (deficient in vacuolar membrane As[III] transporter YCF1) expressing OsTIP1;2 further increased As[III] stress tolerance of both WT and OE plants. The dithizone assay showed that WT plants accumulated high arsenic in shoots, while OE lines accumulated more arsenic in roots than shoots thereby limiting the translocation of arsenic to shoot. The activity of enzymatic and non-enzymatic antioxidants also increased in the OE lines on exposure to As[III]. The tissue-specific localization showed OsTIP1;2 promoter activity in root and root hairs, indicating its possible root-specific function. After As[III] treatment in hydroponic medium, the arsenic translocation factor (TF) for WT was around 0.8, while that of OE lines was around 0.2. Moreover, the arsenic content in the grains of OE lines reduced significantly compared to WT plants.

Keywords: Aquaporins; Arsenic; Rice; Tonoplast intrinsic proteins; Translocation factor.