Promoter sequences of a potato pathogenesis-related gene mediate transcriptional activation selectively upon fungal infection

Abstract

Transcription of at least one member of the potato prp1 gene family, prp1-1, is activated at early stages of potato infection with the late blight fungus Phytophthora infestans. In this paper we present evidence that mRNA encoded by prp1-1 does not accumulate in response to abiotic environmental cues which stimulate transcription of other defence-related genes. Regulatory elements were identified in the 5' terminal region of prp1-1 by assaying the expression pattern of chimeric promoter/beta-glucuronidase gene constructs in transgenic potato. A 273 bp fragment comprising the promoter sequence between positions -402 and -130 was sufficient for rapid and strictly localized transcriptional activation at infection sites during the development of late blight disease. Like the native promoter, this truncated promoter did not mediate transcriptional activation in response to other abiotic stimuli. The use of the identified regulatory region to generate conditional mutations selectively at infection sites is discussed.

Pathogen‐Defence Gene prp1–1 from Potato Encodes an Auxin‐Responsive Glutathione S‐Transferase

“…Plants of potato (Solanum tuberosum L.) cultivars Datura (Rl) or D6sirCe (RO) were grown from tubers according to Martini et al (1993). After 6 weeks, the 4th to 7th fully expanded leaves were detached and inoculated from the abaxial side with 15-20 drops of 20 1.…”

“…A 1.5-kb promoter fragment of the potato prpl-1 gene (positions -1520 to +31; sequence submitted to EMBL data library) was inserted into the plant transformation vector pPTVgus (Martini et al, 1993) via EcoRI and XbaI, resulting in construct PG1.50. The recombinant plasmid was mobilized from E. coli strain S 17-1 to Agrobacterium tumefaciens strain C58Cl-GV3101 harboring the helper plasmid pMP90RK (Koncz et al, 1989).…”

“…Among these are enzymes of the general phenylpropanoid metabolism Becker-AndrC et al, 1991;Joos and Hahlbrock, 1992), enzymes of sesquiterpenoid biosynthesis (Oba et al, 1985;Zook and Kuc, 1991;Choi et al, 1992), as well as chitinases and ~-1,3-glucanases which belong to the group of pathogenesis-related (PR) proteins (Kombrink et al, 1988). In contrast to most other defence-related gene families, mRNA accumulation deriving from the prpl gene family is selectively induced by pathogen attack and not in response to abiotic stimuli, such as wounding, lighvdark switches or heat shock (Taylor et al, 1990;Martini et al, 1993). The importance of this gene family for pathogen defence has been further substantiated by the finding that its genomic locus correlates with a quantitative trait locus for horizontal resistance to P. infestuns (LeonardsSchippers et al, 1994).…”

Structure and genomic organization of the ipiB and ipiO gene clusters of Phytophthora infestans

“…) de Bary is the causal agent of the devastating host plant (Choi et al, 1992;Fritzemeier et al, 1987;Hahlbrock et al, 1989;Martini et al, 1993;Schroder et al, 1992;Taylor et al, 1990). Many of these genes encode products which are thought to be involved in the inhibition of pathogen development.…”

Ensnaring microbes: the components of plant disease resistance

“…If promoters of plant genes specifically upregulated early in the infection process can be identified, for example theprpl-1 promoter of potato (Martini et aL, 1993), the hrs-203J promoter of tobacco (Pontier et al, 1994) or the fisl promoter of flax (Roberts & Pryor, 1995) then it might be possible to drive expression of toxins or race-specific elicitors, such as Avr9, only in the challenged cells and so elicit a hypersensitive response. In the latter situation the plants would also need to express a functional Cf-9 gene.…”