Examination of the Metallothionein Gene Family in Greater Duckweed Spirodela polyrhiza
Issued Date
2023-01-01
Resource Type
eISSN
22237747
Scopus ID
2-s2.0-85145864256
Journal Title
Plants
Volume
12
Issue
1
Rights Holder(s)
SCOPUS
Bibliographic Citation
Plants Vol.12 No.1 (2023)
Suggested Citation
Pakdee O., Tshering S., Pokethitiyook P., Meetam M. Examination of the Metallothionein Gene Family in Greater Duckweed Spirodela polyrhiza. Plants Vol.12 No.1 (2023). doi:10.3390/plants12010125 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/81498
Title
Examination of the Metallothionein Gene Family in Greater Duckweed Spirodela polyrhiza
Author(s)
Author's Affiliation
Other Contributor(s)
Abstract
Duckweeds are aquatic plants that proliferate rapidly in a wide range of freshwaters, and they are regarded as a potential source of sustainable biomass for various applications and the cost-effective bioremediation of heavy metal pollutants. To understand the cellular and molecular basis that underlies the high metal tolerance and accumulation capacity of duckweeds, we examined the forms and transcript profiles of the metallothionein (MT) gene family in the model duckweed Spirodela polyrhiza, whose genome has been completely sequenced. Four S. polyrhiza MT-like genes were identified and annotated as SpMT2a, SpMT2b, SpMT3, and SpMT4. All except SpMT2b showed high sequence homology including the conserved cysteine residues with the previously described MTs from flowering plants. The S. polyrhiza genome appears to lack the root-specific Type 1 MT. The transcripts of SpMT2a, SpMT2b, and SpMT3 could be detected in the vegetative whole-plant tissues. The transcript abundance of SpMT2a was upregulated several-fold in response to cadmium stress, and the heterologous expression of SpMT2a conferred copper and cadmium tolerance to the metal-sensitive ∆cup1 strain of Saccharomyces cerevisiae. Based on these results, we proposed that SpMT2a may play an important role in the metal detoxification mechanism of duckweed.