Genome-wide identification and expression profile analysis of metal tolerance protein gene family in Eucalyptus grandis under metal stresses

Abstract

Metal tolerance proteins (MTPs) as Me2+/H+(K+) antiporters participate in the transport of divalent cations, leading to heavy metal stress resistance and mineral utilization in plants. In the present study, to obtain better knowledge of the biological functions of the MTPs family, 20 potential EgMTPs genes were identified in Eucalyptus grandis and classified into seven groups belonging to three cation diffusion facilitator groups (Mn-CDFs, Zn/Fe-CDFs, and Zn-CDFs) and seven groups. EgMTP-encoded amino acids ranged from 315 to 884, and most of them contained 4–6 recognized transmembrane domains and were clearly prognosticated to localize into the cell vacuole. Almost all EgMTP genes experienced gene duplication events, in which some might be uniformly distributed in the genome. The numbers of cation efflux and the zinc transporter dimerization domain were highest in EgMTP proteins. The promoter regions of EgMTP genes have different cis-regulatory elements, indicating that the transcription rate of EgMTP genes can be a controlled response to different stimuli in multiple pathways. Our findings provide accurate perception on the role of the predicted miRNAs and the presence of SSR marker in the Eucalyptus genome and clarify their functions in metal tolerance regulation and marker-assisted selection, respectively. Gene expression profiling based on previous RNA-seq data indicates a probable function for EgMTP genes during development and responses to biotic stress. Additionally, the upregulation of EgMTP6, EgMTP5, and EgMTP11.1 to excess Cd2+ and Cu2+ exposure might be responsible for metal translocation from roots to leaves.

Heavy Metal Contamination in Soil: Implications for Crop Resilience and Abiotic Stress Management

“…These proteins, which are membrane-bound transporters, play a crucial role in the selective transport of various metals. Variations in their transcript levels may reflect the plant's adaptive response to metal-induced stress [114].…”

Genome-wide identification, expression and function analysis of the MTP gene family in tulip (Tulipa gesneriana)

“…In rice, OsMTP11 may play an important role in Mn and other heavy metal transport in rice ( Zhang and Liu, 2017 ). In Eucalyptus grandis , The up-regulation of EgMTP6 , EgMTP5 and EgMTP11.1 upon excessive exposure to Cd 2+ and Cu 2+ may account for the metal translocation from root to leaf ( Shirazi et al., 2023 ). In Populus trichocarpa , PtrMTP8.1 , PtrMTP9 and PtrMTP10.4 displayed Mn transport capability in yeast cells, while PtrMTP6 was able to transport Co, Fe and Mn ( Gao et al., 2020 ).…”