Induction of tcI 7, a gene encoding a B-subunit of proteasome, in tobacco plants treated with elicitins, salicylic acid or hydrogen peroxide
Etienne. P Anne-Sophie. P Houot. V Jean-Pierre. B Suty. L
FEBS Letters ; 2000 [Vol.466] Pages:213-218
Abstract
We previously isolated, by differential display and 5 RACE (rapid amplification of cDNA ends), cDNAs corresponding to genes activated following cryptogein treatment of tobacco cell suspensions, among them tcI 7 (tcI for tobacco cryptogein Induced), a gene encoding a L L-subunit of proteasome. Here, we
report that tcI 7 was up-regulated in tobacco plants treated with
elicitins (cryptogein and parasiticein) that have been shown to induce a systemic acquired resistance (SAR). Moreover,subsequent inoculation of tobacco with the pathogen Phytophthora parasitica var. nicotianae (Ppn) was shown to induce an additional activation of tcI 7 in tobacco plants pretreated with cryptogein. We also showed an up-regulation of tcI 7 by salicylic acid (SA). Moreover, accumulation of tcI 7 transcripts after treatment with cryptogein or with SA only occurred in NahG 9- tobacco plants that do not express the salicylate hydroxylase and thus are able to accumulate SA and develop a SAR. Suppressed accumulation of tcI 7 transcripts in NahG 8+ tobacco plants after cryptogein or SA treatment correlated with the loss of SAR. H2O2 was also shown to up-regulate tcI 7 in tobacco plants.Using gene walking by PCR we cloned and sequenced the 5 flanking region of tcI 7 containing hypothetical regulatory sequences, especially myb and NF-U UB boxes, that could be responsible for the regulation of tcI 7 by salicylic acid and H2O2 respectively.
Full Text