Antarctic Moss Multiprotein Bridging Factor 1c Overexpression in Arabidopsis Resulted in Enhanced Tolerance to Salt Stress

Abstract

Polytrichastrum alpinum is one of the moss species that survives extreme conditions in the Antarctic. In order to explore the functional benefits of moss genetic resources, P. alpinum multiprotein-bridging factor 1c gene (PaMBF1c) was isolated and characterized. The deduced amino acid sequence of PaMBF1c comprises of a multiprotein-bridging factor (MBF1) domain and a helix-turn-helix (HTH) domain. PaMBF1c expression was induced by different abiotic stresses in P. alpinum, implying its roles in stress responses. We overexpressed PaMBF1c in Arabidopsis and analyzed the resulting phenotypes in comparison with wild type and/or Arabidopsis MBF1c (AtMBF1c) overexpressors. Overexpression of PaMBF1c in Arabidopsis resulted in enhanced tolerance to salt and osmotic stress, as well as to cold and heat stress. More specifically, enhanced salt tolerance was observed in PaMBF1c overexpressors in comparison to wild type but not clearly observable in AtMBF1c overexpressing lines. Thus, these results implicate the evolution of PaMBF1c under salt-enriched Antarctic soil. RNA-Seq profiling of NaCl-treated plants revealed that 10 salt-stress inducible genes were already up-regulated in PaMBF1c overexpressing plants even before NaCl treatment. Gene ontology enrichment analysis with salt up-regulated genes in each line uncovered that the terms lipid metabolic process, ion transport, and cellular amino acid biosynthetic process were significantly enriched in PaMBF1c overexpressors. Additionally, gene enrichment analysis with salt down-regulated genes in each line revealed that the enriched categories in wild type were not significantly overrepresented in PaMBF1c overexpressing lines. The up-regulation of several genes only in PaMBF1c overexpressing lines suggest that enhanced salt tolerance in PaMBF1c-OE might involve reactive oxygen species detoxification, maintenance of ATP homeostasis, and facilitation of Ca2+ signaling. Interestingly, many salt down-regulated ribosome- and translation-related genes were not down-regulated in PaMBF1c overexpressing lines under salt stress. These differentially regulated genes by PaMBF1c overexpression could contribute to the enhanced tolerance in PaMBF1c overexpressing lines under salt stress.

Acetic Acid Treatment Enhances Drought Avoidance in Cassava (Manihot esculenta Crantz)

“…The application of acetic acid increased the expression of various stress response and stress tolerance-related genes, such as heat shock family proteins, HSP20 (Muthusamy et al, 2017), HSP21 (Zhong et al, 2013), HSP70 (Tang et al, 2016; Leng et al, 2017) and HSP90 (Krishna and Gloor, 2001), ER stress-related gene, HOP3 (At4g12400; Fernández-Bautista et al, 2017a,b), catalase 1 and catalase 2 (Zou et al, 2015), multiprotein-bridging factor 1c gene ( MBF1c ; Alavilli et al, 2017), and an outer membrane tryptophan-rich sensory protein (TSPO) (Guillaumot et al, 2009). HSP20 and HSP70 family members function as molecular chaperones and help plants adapt to environmental stress (Tang et al, 2016; Leng et al, 2017; Muthusamy et al, 2017).…”

“…It is plausible to suggest that acetic acid treatment enhances drought avoidance in cassava through the regulation of the ER stress response. Overexpression of P. alpinum multiprotein-bridging factor 1c gene ( PaMBF1c ) enhanced salt tolerance in Arabidopsis (Alavilli et al, 2017). Catalase plays an important role in ABA- and H 2 O 2 -mediated signal transduction and in maintaining H 2 O 2 homeostasis in response to drought (Zou et al, 2015).…”

Integration between ROS Regulatory Systems and Other Signals in the Regulation of Various Types of Heat Responses in Plants

“…However, our recent study demonstrated that Arabidopsis deficient in CNGC2 showed a higher accumulation of MBF1c protein under heat stress during the seedling stage, suggesting that CNGC2-dependent Ca 2+ signaling and ROS regulatory systems might regulate MBF1c pathways [ 44 ]. The integration of MBF1c and Ca 2+ signaling could also be supported by a recent study showing that the overexpression of Antarctic moss MBF1c in Arabidopsis plants resulted in enhanced salt tolerance, accompanied by the activation of ROS-scavenging systems, maintenance of Adenosine triphosphate (ATP) homeostasis, and facilitation of Ca 2+ signaling [ 55 ]. These findings indicate the existence of a complex network involving MBF1c, hormone signals, Ca 2+ signals, and ROS regulatory systems.…”

TsHD1 and TsNAC1 cooperatively play roles in plant growth and abiotic stress resistance of Thellungiella halophile

“…In the H or HN lines, MBF1C and DREB2A were targeted and showed an obviously improved expression (Figure ). AtMBF1c expression was highly induced by heat treatment, and the overexpression of AtMBF1c , TaMBF1c (the homolog of AtMBF1c in wheat) and PaMBF1c (the homolog of AtMBF1c in Polytrichastrum alpinum ) improved the drought and heat tolerance of plants (Suzuki et al ., ; Qin et al ., ; Alavilli et al ., ). It has been shown that MBF1C acts between the TF bZIP and TATA‐box binding protein (TBP) (Takemaru et al ., ), and parts of the TF bZIP (such as AtbZIP28) coordinated with the TF Hsfs, which in turn stimulated the expression of HSP genes (Kataoka et al ., ).…”