Two cold-inducible genes encoding lipid transfer protein LTP4 from barley show differential responses to bacterial pathogens

Abstract

The barley genes HvLtp4.2 and HvLtp4.3 both encode the lipid transfer protein LTP4 and are less than 1 kb apart in tail-to-tail orientation. They differ in their non-coding regions from each other and from the gene corresponding to a previously reported Ltp4 cDNA (now Ltp4.1). Southern blot analysis indicated the existence of three or more Ltp4 genes per haploid genome and showed considerable polymorphism among barley cultivars. We have investigated the transient expression of genes HvLtp4.2 and HvLtp4.3 folio wing transformation by particle bombardment, using promoter fusions to the j9-glucuronidase repórter sequence. In leaves, activities of the two promoters were of the same order as those of the sucrose synthase (Ssl) and cauliflower mosaic virus 35S promoters used as controls. Their expression patterns were similar, except that Ltp4.2 was more active than Ltp4.3 in endosperm, and Ltp4.3 was active in roots, while Ltp4.2 was not. The promoters of both genes were induced by low temperature, both in winter and spring barley cultivars. Northern blot analysis, using the Zíp4-specific probé, indicated that Xanthomonas campestris pv. translucens induced an increase over basal levéis of Ltp4 mRNA, while Pseudomonas syringae pv. japónica caused a decrease. The Ltp4.3-Gus promoter fusión also responded in opposite ways to these two compatible bacterial pathogens, whereas the Ltp4.2-Gus construction did not respond to infection.

Plant Allergens and Pathogenesis-Related Proteins

“…LTPs contain eight conserved cysteine residues forming four disulfide bridges which makes them highly resistant to harsh temperature and pH changes [94]. Coldness inducible genes encoding LTP in barley show differential response to bacterial pathogens (HvLtp4.2 and HvLtp4.3; [95]).…”

Isolation and characterization of lipid transfer protein (LTP) genes from a wheat-rye translocation line

“…In earlier studies the transcripts of the LTP genes of barley reached high steady-state levels 7 days after the initiation of a low-temperature treatment (Dunn et al 1994) and the promoters of the LTP genes were also induced by low temperature (Molina et al 1996). We found that TaLTP1 and TaLTP2 were continuously expressed both in control plants and in cold-treated plants over a period of 24 h.…”

“…The expression of LTPs can be induced by abiotic and/or biotic stresses such as cold, water deficit, NaCl, heavy metal treatment, or pathogen invasion (TorresSchumann et al 1992;Molina et al 1996;ColmeneroFlores et al 1997;Hollenbach et al 1997;Pearce et al 1998). The expression pattern of each gene within a family is typically affected differentially by plant growth stage, anatomy, and biotic and abiotic stress (Molina et al 1996;Vignols et al 1997;Arondel et al 2000).…”

“…The expression pattern of each gene within a family is typically affected differentially by plant growth stage, anatomy, and biotic and abiotic stress (Molina et al 1996;Vignols et al 1997;Arondel et al 2000). cDNAs of LTPs of hexaploid wheat (Triticum aestivum L., 2n=42) have not yet been reported.…”

“…Lipid transfer protein genes have been isolated from numerous plants, including Arabidopsis thaliana (Thoma et al 1994;Arondel et al 2000), Zea mays (Sossountzov et al 1991), Hordeum vulgare (Gausing 1994;Molina et al 1996;Pearce et al 1998;Chen and Foolad 1999), Oryza sativa (Vignols et al 1997), and Sorghum vulgare (Pelèse-Siebenbourg et al 1994). Plant LTPs have been shown to enhance the in vitro transfer of phospholipids between membranes and to bind acyl chains (for review see Kader 1996).…”