Characterization of a novel LmSAP gene promoter from Lobularia maritima: Tissue specificity and environmental stress responsiveness

PLoS One. 2020 Jul 31;15(7):e0236943. doi: 10.1371/journal.pone.0236943. eCollection 2020.

Abstract

Halophyte Lobularia maritima LmSAP encodes an A20AN1 zinc-finger stress-associated protein which expression is up-regulated by abiotic stresses and heavy metals in transgenic tobacco. To deepen our understanding of LmSAP function, we isolated a 1,147 bp genomic fragment upstream of LmSAP coding sequence designated as PrLmSAP. In silico analyses of PrLmSAP revealed the presence of consensus CAAT and TATA boxes and cis-regulatory elements required for abiotic stress, phytohormones, pathogen, and wound responses, and also for tissue-specific expression. The PrLmSAP sequence was fused to the β-glucuronidase (gusA) reporter gene and transferred to rice. Histochemical GUS staining showed a pattern of tissue-specific expression in transgenic rice, with staining observed in roots, coleoptiles, leaves, stems and floral organs but not in seeds or in the root elongation zone. Wounding strongly stimulated GUS accumulation in leaves and stems. Interestingly, we observed a high stimulation of the promoter activity when rice seedlings were exposed to NaCl, PEG, ABA, MeJA, GA, cold, and heavy metals (Al3+, Cd2+, Cu2+ and Zn2+). These results suggest that the LmSAP promoter can be a convenient tool for stress-inducible gene expression and is a potential candidate for crop genetic engineering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crops, Agricultural / genetics
  • Gene Expression Regulation, Plant / genetics*
  • Genetic Engineering
  • Glucuronidase / metabolism
  • Metals, Heavy / metabolism
  • Nicotiana / genetics
  • Organ Specificity
  • Oryza / genetics
  • Plant Leaves / metabolism
  • Plant Roots / metabolism
  • Plant Stems / metabolism
  • Plants, Genetically Modified / metabolism
  • Promoter Regions, Genetic*
  • Salt-Tolerant Plants / genetics*
  • Stress, Physiological / genetics*
  • Zinc Fingers / genetics*

Substances

  • Metals, Heavy
  • Glucuronidase

Grants and funding

This study was funded by Ministry of Higher Education and Scientific Research of Tunisia, contrat programme 2019–2022. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.