The Arabidopsis‐related halophyte Thellungiella halophila: boron tolerance via boron complexation with metabolites?

Abstract

Tolerance to boron (B) is still not completely understood. We tested here the hypothesis that Thellungiella halophila, an Arabidopsis thaliana-related 'extremophile' plant, with abundance of B in its natural environment, is tolerant to B, and examined the potential mechanisms of this tolerance.

Genome Structures and Transcriptomes Signify Niche Adaptation for the Multiple-Ion-Tolerant Extremophyte Schrenkiella parvula

“…This result leads to another testable hypothesis, that the increased expression of BOR5 may be related to S. parvula's ability to survive high concentrations of borates, as illustrated in Figure 1. Interestingly, both S. parvula and E. salsugineum share the Tlc event in the 59 upstream region of BOR5 (data not shown), suggesting a genomic feature conserved among the two closely related species that share tolerance to boron toxicity (Lamdan et al, 2012). The tolerance to boron toxicity is further supported by increased copy numbers and basal-level expression of aquaporin genes related to boron transport, such as NOD26-LIKE INTRINSIC PRO-TEIN5;1 (NIP5;1) and NIP6;1 (Tanaka et al, 2008;Kato et al, 2009), in S. parvula (Table II).…”

Comparative profiling of membrane lipids during water stress in Thellungiella salsuginea and its relative Arabidopsis thaliana

“…T. salsuginea can, however, tolerate high-salinity, cold, heat, boron, and nitrogen-limitation stresses (Gong et al, 2005;Griffith et al, 2007;Ishikawa et al, 2007;Kant et al, 2008;Lamdan et al, 2012;Zhang et al, 2012a). The genes of T. salsuginea have high sequence identity (90-95% at cDNA level) to those of A. thaliana, and cDNA microarrays of A. thaliana have been used for T. salsuginea research (Taji et al, 2004).…”

Anastatica hierochuntica, an Arabidopsis Desert Relative, Is Tolerant to Multiple Abiotic Stresses and Exhibits Species-Specific and Common Stress Tolerance Strategies with Its Halophytic Relative, Eutrema (Thellungiella) salsugineum

“…One successful strategy has been to study extremophyte Arabidopsis relatives ( Brassicaceae ) such as the metal hyperaccumulator Arabidopsis halleri (Hanikenne et al, 2008), and the halophytes, Schrenkiella parvula (formerly Thellungiella parvula ) and Eutrema salsugineum (formerly Thellungiella salsuginea or Thellungiella halophila ) (Volkov et al, 2003; Inan et al, 2004; Orsini et al, 2010; Koch and German, 2013). In addition to being salt-tolerant (e.g., Inan et al, 2004; Taji et al, 2004; Kant et al, 2006), E. salsugineum is also tolerant to low soil nitrogen (Kant et al, 2008), high boron levels (Lamdan et al, 2012), low phosphate levels (Velasco et al, 2016), heat stress (Higashi et al, 2013), and shows similar tolerance to cold and freezing stress as Arabidopsis (Griffith et al, 2007; Lee et al, 2012). A number of factors contribute to E. salsugineum stress tolerance including constitutive up- and down-regulation of stress tolerance genes and metabolites suggesting that E. salsugineum is “primed” for stress, gene copy number expansion of ion transport-related genes, sub-functionalization and neo-functionalization of duplicated genes, biased codon usage facilitating more efficient translation of proteins related to ion transportation, and the possible involvement of lineage-specific genes (Taji et al, 2004; Gong et al, 2005; Kant et al, 2006, 2008; Lugan et al, 2010; Oh et al, 2010, 2012, 2014; Sun et al, 2010; Dassanayake et al, 2011; Wu et al, 2012; Champigny et al, 2013; Kazachkova et al, 2013; Yang et al, 2013).…”