Elicitor rapidly induces chalcone synthase mRNA in Phaseolus vulgaris cells at the onset of the phytoalexin defense response

Abstract

DNAs complementary to poly(A)+ RNA present in elicitor-treated cells of Phaseolus vulgaris L. were inserted into pBR325 and used to transform Escherichia coli strain JA221. A clone was identified that contained sequences complementary to mRNA encoding chalcone synthase, a regulatory enzyme of phenylpropanoid biosynthesis, which catalyzes the first reaction of a branch pathway specific to flavonoid and isoflavonoid biosynthesis. Rapid, marked but transient increases in chalcone synthase mRNA in response to elicitor treatment were observed by RNA blot hybridization with 32P-labeled chalcone synthase cDNA sequences. Induction of chalcone synthase mRNA governs the rate of enzyme synthesis throughout the phase of rapid increase in enzyme activity at the onset of accumulation of isoflavonoid-derived phytoalexins. The data are consistent with the hypothesis that elicitor causes a rapid transient stimulation of transcription of chalcone synthase gene(s) as an early event in the expression of the phytoalexin defense response.

The Role of Octadecanoids and Functional Mimics in Soybean Defense Responses

“…Total RNA of treated soybean cells was prepared according to Schröder et al (1979) and 15 µg per lane were blotted onto Biodyne-A membranes (Pall, Dreieich, Germany). Hybridization probes used were: 3 kbp soybean actin gene, bean (Phaseolus vulgaris) chalcone synthase 1 (CHS) cDNA (Ryder et al, 1984), soybean reductase co-acting with CHS (CHR) partial cDNA clone p1 (Welle et al, 1991), soybean flavonoid 6-hydroxylase (F6H) gene-specific cDNA fragment Latunde-Dada et al, 2001), soybean 3,9-dihydroxypterocarpane 6a-hydroxylase (D6aH) gene-specific probe generated by PCR from the cDNA , soybean Gmhsp-26A glutathione S-transferase (GST) cDNA (Czarnecka et al, 1988, kindly provided by R. Tenhaken, University of Kaiserslautern, Germany), and partial soybean lipoxygenase 4 (LOX4, corresponding to swissprot accession P38417) cDNA (J. Fliegmann, unpublished).…”

Plant defence genes are induced in the pathogenic interaction between bean roots and Fusarium solani, but not in the symbiotic interaction with the arbuscular mycorrhizal fungus Glomus mosseae

“…culaire des Plantes du CNRS, Strasbourg, France). The pG101 class I β-1,3-glucanase (Edington, Lamb & Dixon, 1991) was from Dr R. A. Dixon (The Samuel Roberts Noble Foundation, Ardmore, OK, USA), and pCHS1, encoding chalcone synthase, (Ryder et al, 1984) pPAL5, coding for phenylalanine ammonia-lyase (Edwards et al, 1985) and pH1, a cDNA clone encoding a constitutively expressed gene of unknown function (Lawton & Lamb, 1987), were from Dr C. J. Lamb (The Salk Institute for Biological Studies, La Jolla, CA, USA).…”

Fungal Elicitor-Induced Bean Proline-Rich Protein mRNA Down-Regulation Is Due to Destabilization That Is Transcription and Translation Dependent.

“…32P-labeled probes were phenylalanine ammonia-lyase (PAL) cDNA PALB (Edwards et al, 1985), chalcone synthase (CHS) cDNA CHS5 (Ryder et al, 1984). chalcone isomerase (CHI) cDNA CHl7 (Mehdy and Lamb, 1987), the Hincll-EcoRI fragment of the PvPRP7 cDNA (Sheng et al, 1991), the H7 cDNA (Lawton and Lamb, 1987), and soybean tubulin S82X3 (Han et al, 1991).…”