Osmotin gene expression is controlled by elicitor synergism

Abstract

Arachidonic acid (AA), a fatty‐acid fungal elicitor, and a cellulase preparation from Aspergillus niger, a protein‐type fungal elicitor, induced osmotin gene expression. Both elicitors activated the osmotin promoter fused to a β‐glucuronidase (GUS) reporter gene in a tissue‐specific manner in tobacco seedlings (Nicotiana tabacum L. cv. Wisconsin 38). The cellulase preparation was more effective than AA at the concentrations tested and, unlike AA, also induced the accumulation of osmotin mRNA and protein. Combinations of AA and the cellulase preparation had a greater than additive effect on the activation of the osmotin promoter and the accumulation of osmotin mRNA and protein. Both AA and the cellulase preparation, when applied separately, were virtually ineffective in the induction of the osmotin promoter in cotyledon tissues. However, together they were able to induce synergistically GUS fused to the osmotin promoter. Increases in osmotin‐promoter‐driven GUS activity and accumulation of osmotin mRNA induced by AA, the cellulase preparation or their combination were reversed by norbornadiene, an ethylene action inhibitor, indicating that ethylene is involved in the induction of the osmotin gene by these elicitors.

Induction of a cDNA clone from rice encoding a class II small heat shock protein by heat stress, mechanical injury, and salicylic acid

“…Total RNA extraction from the treated rice seedlings and poly(A) + RNA purification by oligo (dT) cellulose chromatography were performed according to Chang et al [30] and Lee et al [16]. The first-strand cDNAs were synthesized from the poly(A) + RNAs of 3-day-old heat-shocked (2 h at 41 8C) rice seedlings using SuperScript II RNase H À Reverse Transcriptase (Invitrogen).…”

Characterization of genes for novel thaumatin-like proteins in Cryptomeria japonica

“…Expression of the Cry j 3.3, Cry j 3.4 and Cry j 3.6 genes was strongly induced by AA (Figure 8), which is an effective defense response elicitor in potato tubers (Bostock et al 1981). Chang et al (1995) showed that AA alone was not an effective inducer of the gene for osmotin in tobacco seedlings but AA plus a preparation of cellulase stimulated expression of this gene. We found that AA alone had a significant effect on gene transcript levels for some TLPs in C. japonica seedlings.…”

“…In a previous study, AA, which is a fatty-acid fungal elicitor, and a preparation of cellulase from Aspergillus niger, which is a protein-type fungal elicitor, induced the expression of the gene for osmotin in tobacco (Chang et al 1995). To examine the effects of AA and cellulase on the levels of Cry j 3 transcripts, we exposed seedlings of C. japonica to AA, cellulase or a combination of the two (Figure 8).…”