Abstract

Salt tolerance is a commercially important trait that affects plant species around the globe. Cellular response to saline environments is a well studied but complex system that is far from being completely understood. The SALT OVERLY SENSITIVE 1 (SOS1) gene is a critical component of salt tolerance in many species, encoding a plasma membrane Na+/H+ antiporter that plays an important role in germination and growth in saline environments. Here we report a preliminary investigation of salt tolerance in quinoa (Chenopodium quinoa Willd.). Quinoa is a halophytic grain crop of the Chenopodiaceae family with impressive nutritional content and an increasing world-wide market. Many quinoa varieties have impressive salt tolerance characteristics and research suggests quinoa may utilize novel mechanisms to confer salt tolerance. At this time there is no published data on the molecular characteristics of those mechanisms. We report the identification and sequencing of the SOS1 gene in quinoa, including a full length cDNA sequence of 3490 bp and a full length genomic clone of 21314 bp. Sequence analysis predicts the quinoa SOS1 homolog spans 23 exons and is comprised of 3474 bp of coding sequence (excluding the stop codon). Introns comprise 17840 bp of the genomic clone and range in size from 77 to 2123 bp. The predicted protein contains 1158 amino acid residues and aligns closely with SOS1 homologs of other species. The quinoa SOS1 homolog contains two putative domains, a Nhap cation-antiporter domain and a cyclic-nucleotide binding domain. Sequence analyses of both cDNA fragments and intron fragments suggest that two SOS1 loci are present in the quinoa genome that are likely orthologous loci derived from the ancestral diploid genomes of the modern allotetraploid quinoa genome. This report represents the first molecular characterization of a putative salt-tolerance gene in C. quinoa.

Degree

MS

College and Department

Life Sciences; Plant and Wildlife Sciences

Rights

http://lib.byu.edu/about/copyright/

Date Submitted

2007-07-17

Document Type

Thesis

Handle

http://hdl.lib.byu.edu/1877/etd2005

Keywords

Chenopodium quinoa, salt tolerance, SOS1

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