Functional Identification of Salt-Stress-Related Genes Using the FOX Hunting System from Ipomoea pes-caprae

Abstract

Ipomoea pes-caprae is a seashore halophytic plant and is therefore a good model for studying the molecular mechanisms underlying salt and stress tolerance in plant research. Here, we performed Full-length cDNA Over-eXpressor (FOX) gene hunting with a functional screening of a cDNA library using a salt-sensitive yeast mutant strain to isolate the salt-stress-related genes of I. pes-caprae (IpSR genes). The library was screened for genes that complemented the salt defect of yeast mutant AXT3 and could grow in the presence of 75 mM NaCl. We obtained 38 candidate salt-stress-related full-length cDNA clones from the I. pes-caprae cDNA library. The genes are predicted to encode proteins involved in water deficit, reactive oxygen species (ROS) scavenging, cellular vesicle trafficking, metabolic enzymes, and signal transduction factors. When combined with the quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses, several potential functional salt-tolerance-related genes were emphasized. This approach provides a rapid assay system for the large-scale screening of I. pes-caprae genes involved in the salt stress response and supports the identification of genes responsible for the molecular mechanisms of salt tolerance.

Isolation and characterization of an atypical LEA gene (IpLEA) from Ipomoea pes-caprae conferring salt/drought and oxidative stress tolerance

“…These data, therefore, suggest that the function of IpLEA is associated with water-deficit tolerance, probably by holding water molecular or ROS, and then reducing the damage by its protective roles to maintain the cellular basal metabolic activities. This conclusion is further supported by our previous results whereby the induced expression of the IpLEA protein in yeast could elevate the survival capability of yeast cells under salt and H 2 O 2 stress 26 .…”

“…The IpLEA cDNA was determined from a cDNA library of I . pes-caprae by FOX-hunting technique 26 . The cDNA sequence of IpLEA encodes a polypeptide of 313 amino acid residues with a 61 bp 5′ untranslated region (UTR) and a 390 bp 3′ UTR (including a polyA tail).…”

“…A full-length cDNA library from I . pes-caprae was constructed and screened with a FOX (Full‐length cDNA Over‐eXpressing) gene hunting system using a yeast salt sensitive mutant (AXT3) complementary assay approach 26 . Thereafter, a full-length cDNA ( IpSR26 ) encoding a LEA protein that could rescue the phenotype of AXT3 was selected for further investigation.…”

“…We previously generated a cDNA library from salt-treated I . pes-caprae seedlings, including both the aerial parts and roots, using a pYES-DEST52 shuttle vector, and described a series of salt stress-related genes from this library 26 . Of these, a full-length cDNA encoding a LEA protein ( IpSR26 , IpLEA , GenBank Accession No.…”

Nutrient availability affects the polar lipidome of Halimione portulacoides leaves cultured in hydroponics

“…Halophyte plants display unique physiological and ecological adaptations to salt-marsh ecosystems, which allow them to live and thrive under a wide range of salt concentrations that most plants are unable to tolerate [1][2][3][4] . These plants have been investigated in several contexts, providing important insights on salt-tolerance mechanisms in order to improve salt-sensitive crops [5][6][7] . Moreover, their potential as alternative agricultural crops have also been investigated for multiple applications [8][9][10][11][12] .…”