PeaT1-induced systemic acquired resistance in tobacco follows salicylic acid-dependent pathway

Abstract

Systemic acquired resistance (SAR) is an inducible defense mechanism which plays a central role in protecting plants from pathogen attack. A new elicitor, PeaT1 from Alternaria tenuissima, was expressed in Escherichia coil and characterized with systemic acquired resistance to tobacco mosaic virus (TMV). PeaT1-treated plants exhibited enhanced systemic resistance with a significant reduction in number and size of TMV lesions on wild tobacco leaves as compared with control. The quantitative analysis of TMV CP gene expression with real-time quantitative PCR showed there was reduction in TMV virus concentration after PeaT1 treatment. Similarly, peroxidase (POD) activity and lignin increased significantly after PeaT1 treatment. The real-time quantitative PCR revealed that PeaT1 also induced the systemic accumulation of pathogenesis-related gene, PR-1a and PR-1b which are the markers of systemic acquired resistance (SAR), NPR1 gene for salicylic acid (SA) signal transduction pathway and PAL gene for SA synthesis. The accumulation of SA and the failure in development of similar level of resistance as in wild type tobacco plants in PeaT1 treated nahG transgenic tobacco plants indicated that PeaT1-induced resistance depended on SA accumulation. The present work suggested that the molecular mechanism of PeaT1 inducing disease resistance in tobacco was likely through the systemic acquired resistance pathway mediated by salicylic acid and the NPR1 gene.

Overexpression of the PeaT1 Elicitor Gene from Alternaria tenuissima Improves Drought Tolerance in Rice Plants via Interaction with a Myo-Inositol Oxygenase

“…In the study, we observed that PeaT1OE plants showed increased drought-tolerant compared with WT, with higher survival rate in OE ( Figure 1 ). Thus, PeaT1’s function in drought resistance is similar to another elicitor Harpin, which could enhances drought tolerance in rice (Zhang W. et al, 2011). These results suggested that PeaT1 played crucial roles in plant improvement tolerance of drought.…”

“…Harpin, the first reported elicitor from the bacterium Erwinia amylovora (Wei et al, 1992; He et al, 1993), could activate the hypersensitive response and growth systems in several crops. The PeaT1 elicitor isolated from Alternaria tenuissima induces the systemic accumulation of the pathogenesis-related proteins PR-1a and PR-1b, which are markers for systemic acquired resistance (Zhang W. et al, 2011). Elicitors may also influence plant resistance to environmental stresses, especially drought.…”

Purification and Characterization of a Novel Hypersensitive Response-Inducing Elicitor from Magnaporthe oryzae that Triggers Defense Response in Rice

“…This elicitor protein, MoHrip1, can induce the transient expression of PR genes in rice and increase the resistance of rice seedlings to M. oryzae . Previously, we reported the isolation of some protein elicitors, such as PeaT1, PemG1 and PebC1 [27], [41], [42], from plant pathogenic fungi. All of these elicitors enhanced plant disease resistance, but none of them could induce the HR in plants.…”

Plant Resistance Inducers against Pathogens in Solanaceae Species—From Molecular Mechanisms to Field Application

“…The protein PeaT1 from Alternaria tenuissima , produced in Escherichia coli , and thereafter used to treat tobacco led to systemic resistance and significant reduction in both number and size of TMV lesions on leaves [56]. Reduction in TMV concentration was also confirmed by qPCR.…”