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

Abstract

In bean cells treated with fungal elicitor, the transcripts of PvPRP1, a gene encoding a proline-rich protein, decreased to ~6% of the original level within 4 hr. The apparent mRNA half-life during the period of rapid degradation was ~45 min. The rate of PvPRP1 gene transcription remained constant over this period, as determined by nuclear run-off assays, indicating a decrease in mRNA stability. By using actinomycin D to block transcription, the half-life of PvPRP1 mRNA in unelicited cells was estimated to be ~60 hr. In cells treated with actinomycin D followed by the addition of elicitor, the PvPRP1 mRNA half-life was ~18 hr, whereas cells treated with these reagents in reciprocal order exhibited a half-life of ~6 hr. The protein synthesis inhibitors emetine and anisomycin also inhibited the rate of PvPRP1 mRNA degradation in elicited cells. Based on these data, we concluded that the rapid decrease in the PvPRP1 mRNA level in elicited cells is due to destabilization, which is dependent on new RNA and protein synthesis.

Mutants of Arabidopsis defective in a sequence-specific mRNA degradation pathway

“…1 C and D). The disparity between the effect of the DST sequence on the steady-state abundance and the half-life of the HPH transcript (12.5-fold vs. 3-fold) is most likely caused by dampening that is commonly observed when general inhibitors of transcription are used to measure mRNA decay rates (10,35,(37)(38)(39). Nonetheless, it is clear that the DST element has reduced the half-life of the HPH mRNA in 1519-31.…”

“…3A, Table 1), and differences in mRNA abundance are often not fully reflected in differences in mRNA half-lives when measured by using general inhibitors of transcription (10,35,(37)(38)(39), as mentioned earlier. For example, in the case of the HPH mRNA, we observed that the 12.5-fold increase in mRNA abundance of the HPH and HPH-DST mRNA was reflected as a 3-fold increase in measured mRNA stability ( Fig.…”

Emerging role for RNA‐based regulation in plant immunity

“…In Arabidopsis it was estimated that 1% of the transcripts have a half-life of < 60 min, and that these highly unstable transcripts are often associated with the circadian timing system and the response to mechanical stimulation (Gutierrez et al, 2002). With respect to pathogen defense, early on destabilization of a transcript encoding the PvPRP1 (Phaseolus vulgaris proline-rich protein (1) cell wall protein in bean has been reported in response to the elicitor of Colletotrichum lindemuthianum (Zhang et al, 1993). The PvPRP1 3′ untranslated region (UTR) interacts with a 50 kDa protein that presumably has a role in mRNA destabilization, as its RNAbinding activity inversely correlates with PvPRP1 mRNA levels (Zhang & Mehdy, 1994).…”

Bean Ribonuclease‐Like Pathogenesis‐Related Protein Genes (Ypr10) Display Complex Patterns of Developmental, Dark‐Induced and Exogenous‐Stimulus‐Dependent Expression

“…Current models favor parameters inherent to the mRNA itself such as cap structures or poly(A)-tail structures as major regulatory factors for mRNA destabilisation (Sachs, 1993). Destabilisation of mRNAs is an active and selective process, which requires newly synthesized compounds and specific binding to particular sites in an mRNA (Fritz et al, 1991;Zhang et al, 1993, Zhang andMehdy, 1994). In the heat-shock responses, selective degradation of existing mRNAs has been shown to assist in the rapid restructuring of the cellular pattern of protein synthesis (Belanger et al, 1986;Brodl and Ho, 1991).…”