Metallochaperone OsHIPP9 is involved in the retention of cadmium and copper in rice. (8th March 2023)

• Record Type: Journal Article
• Authors: Xiong, Shuo; Kong, Xiaohang; Chen, Guoqiang; Tian, Lihong; Qian, Dandan; Zhu, Zhen; Qu, Le Qing
• Is Part Of: Plant, cell and environment. Volume 46:Number 6(2023)
• Page Start: 1946
• Page End: 1961
• Publication Date: 2023-03-08
• Subjects: heavy metal associated isoprenylated plant protein -- node; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.14576
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Metallochaperones are a unique class of proteins that play crucial roles in metal homoeostasis and detoxification. However, few metallochaperones have been functionally characterised in rice. Heterologous expression of Heavy metal‐associated Isoprenylated Plant Protein 9 (OsHIPP9), a metallochaperone, altered yeast tolerance to cadmium (Cd) and copper (Cu). We investigated the physiological role of OsHIPP9 in rice. OsHIPP9 was primarily expressed in the root exodermis and xylem region of enlarged vascular bundles (EVB) at nodes. KO of OsHIPP9 increased the Cd concentrations of the upper nodes and panicle, but decreased Cd in expanded leaves. KO of OsHIPP9 decreased Cu uptake and accumulation in rice. Constitutive OX of OsHIPP9 increased Cd and Cu accumulation in aboveground tissues and brown rice. OsHIPP9 showed binding capacity for Cd and Cu. We propose that OsHIPP9 has dual metallochaperone roles, chelating Cd in the xylem region of EVB for Cd retention in the nodes and chelating Cu in rice roots to aid Cu uptake. Summary Statement: Metallochaperones play crucial roles in metal homoeostasis and detoxification. However, the functions of metallochaperones remained poorly understood in rice. We revealed the dual roles of metallochaperone OsHIPP9, chelating cadmium (Cd) in the xylem region of enlarged vascular bundles for Cd retention in the nodes and chelating copper (Cu) in rice roots to aid Cu uptake, which may aid controlling Cd and Cu distribution in rice through biotechnological strategies.