Isolation and Functional Validation of Salinity and Osmotic Stress Inducible Promoter from the Maize Type-II H+-Pyrophosphatase Gene by Deletion Analysis in Transgenic Tobacco Plants

Abstract

Salinity and drought severely affect both plant growth and productivity, making the isolation and characterization of salinity- or drought-inducible promoters suitable for genetic improvement of crop resistance highly desirable. In this study, a 1468-bp sequence upstream of the translation initiation codon ATG of the promoter for ZmGAPP (maize Type-II H+-pyrophosphatase gene) was cloned. Nine 5´ deletion fragments (D1–D9) of different lengths of the ZmGAPP promoter were fused with the GUS reporter and translocated into tobacco. The deletion analysis showed that fragments D1–D8 responded well to NaCl and PEG stresses, whereas fragment D9 and CaMV 35S did not. The D8 segment (219 bp; -219 to -1 bp) exhibited the highest promoter activity of all tissues, with the exception of petals among the D1–D9 transgenic tobacco, which corresponds to about 10% and 25% of CaMV 35S under normal and NaCl or PEG stress conditions, respectively. As such, the D8 segment may confer strong gene expression in a salinity and osmotic stress inducible manner. A 71-bp segment (-219 to -148 bp) was considered as the key region regulating ZmGAPP response to NaCl or PEG stress, as transient transformation assays demonstrated that the 71-bp sequence was sufficient for the salinity or osmotic stress response. These results enhance our understanding of the molecular mechanisms regulating ZmGAPP expression, and that the D8 promoter would be an ideal candidate for moderating expression of drought and salinity response genes in transgenic plants.

Genome-Wide Analysis of the Aquaporin Gene Family in Chickpea (Cicer arietinum L.)

“…The presence of these stress-responsive cis- elements in CaAQPs correlates to high expression in response to drought, salinity, and cold stress. The ABRE and MBS cis- elements have been previously reported to be involved in ABA-mediated osmotic stress signaling in the regulation of drought-inducible gene expressions (Abreu and Aragão, 2007; Hou et al, 2016), whereas cis- element LTR is a low-temperature-responsive element and involved in the expression of cold-regulated genes (Brown et al, 2001). The link between the presence of stress-related cis- acting elements and the differential expression of aquaporin genes under various stress conditions have been reported in several plants (Alexandersson et al, 2010; Wang L. et al, 2015).…”

MTA, an RNA m6A Methyltransferase, Enhances Drought Tolerance by Regulating the Development of Trichomes and Roots in Poplar

“…The Agrobacterium was collected by centrifugation for 5 min at 5000 g. The cultures were resuspended in a medium containing 5 mM MES, 100 mM MgCl 2 (pH 5.6), and 0.1 mM acetylsyringone [64]. The Agrobacterium cells were then injected into the abaxial surfaces of the tobacco leaves by using a needleless syringe.…”

Isolation and functional characterization of three abiotic stress-inducible (Apx, Dhn and Hsc70) promoters from pearl millet (Pennisetum glaucum L.)

“…The OsABA2 pro drives a low constitutive expression under normal conditions, but high expression in response to ABA, salt and drought stresses. Promoter from the maize Type-II H + -pyrophosphatase gene showed higher expression when compared to constitutive 35S pro under drought and salinity stresses [16]. Similarly, AtUSP has been found more active in response to phytohormones as well as multiple abiotic stresses.…”