Posttranscriptional control in the expression of the genes coding for high-light-regulated HL#2 proteins

Abstract

An antibody was raised against the protein HL#2 which is a nuclear-encoded light-stress-induced protein of barley (Hordeum vulgare L.). The expression of the mRNA and the protein of HL#2 was determined under the influence of high light and methyl jasmonate. The mRNA of HL#2 was induced by high light (1800 &mgr;mol m(-2) s(-1) and 25 degrees C) and the steady-state levels remained elevated for up to 48 h of exposure to high-light stress. In contrast, using an antibody against HL#2 there was no observable change in the level of HL#2 proteins of 18 kDa and 15.5 kDa during the same treatment. These data indicate a pronounced stress-induced control of HL#2 expression at a post-transcriptional level. In the presence of methyl jasmonate (45 &mgr;M), the induction of HL#2 occurred together with that of the two most closely related jasmonate-inducible proteins (JIPs) of 32.6 and 32.7 kDa, as judged by their cross-reactivity with the antibody against HL#2. In contrast to the mRNA and protein levels of early light-inducible proteins (ELIPs) in green barley, those of HL#2 appeared not to be influenced by low temperatures. Therefore, the control of ELIPs and HL#2 by high light fluxes may be measured via the same photoreceptor but must, at least partially, be under the control of two divergent signal transduction chains.

Characterisation of plant tocopherol cyclases and their overexpression in transgenic Brassica napus seeds

“…Hence, these findings suggest that the recombinant Arabidopsis and maize cyclase activities differ, at least under in vitro conditions, from the previously reported data obtained with the purified TC from A. variabilis [32], which shows no pronounced specificity with regard to degree and position of methylation at the aromatic ring of the substrate. Porfirova et al [17] and Cheng et al [50] analysed the tocopherol compositions of Arabidopsis mutants deficient in either TC [17] or MPBQ methyltransferase activity [40] and provided strong evidence that the Arabidopsis TC is encoded by a single copy gene and can utilise not only DMPBQ but also MPBQ as substrate in planta. The tocopherol isoforms derived from MBPQ, namely δ‐ and β‐tocopherol, are only minor components in leaves and seeds of wild‐type Arabidopsis plants.…”

“…Total RNA was extracted from leaves of A. thaliana ecotype Columbia and Z. mays cv. Magister using a LiCl‐RNA isolation method [40]. Oligo‐dT‐Dynabeads (Dynal Biotech GmbH, Hamburg, Germany) were used for mRNA isolation and first strand cDNA synthesis was carried out with MMLV reverse transcriptase (Promega, Madison, WI, USA) according to the manufacturer's instructions.…”

Purification and characterisation of a jacalin-related, coleoptile specific lectin from Hordeum vulgare

“…Total RNA was isolated from leaves and coleoptiles, separated by electrophoresis on agarose gels containing formaldehyde and then transferred onto Biodyne-B transfer membranes (Pall GmbH, Dreieich, Germany) as described by Menhaj et al (1999). Each lane was loaded with 10 g RNA.…”

Characterization by suppression subtractive hybridization of transcripts that are differentially expressed in leaves of apple scab-resistant and susceptible cultivars of Malus domestica

“…Semi quantitative determination of transcript levels by RT-PCR Total RNA was isolated as described previously by Menhaj et al (1999), treated with DNase and subsequently converted to cDNA using Moloney Murine Leukemia Virus reverse transcriptase as recommended by the manufacturer (Clontech). The cDNA (1 ll) was used directly for PCR with 1 U of Taq polymerase (Sigma, MO, USA) in the presence of dNTPs at 200 lM and the appropriate primers at 1 lM.…”