Characterization and Antifungal Properties of Wheat Nonspecific Lipid Transfer Proteins

Abstract

This study simultaneously considered the phylogeny, fatty acid binding ability, and fungal toxicity of a large number of monocot nonspecific lipid transfer proteins (ns-LTP). Nine novel full-length wheat ns-LTP1 clones, all possessing coding sequences of 348 bp, isolated from abiotic- and biotic-stressed cDNA libraries from aerial tissues, exhibited highly conserved coding regions with 78 to 99 and 71 to 100% identity at the nucleotide and amino acid levels, respectively. Phylogenetic analyses revealed two major ns-LTP families in wheat. Eight wheat ns-LTP genes from different clades were cloned into the expression vector pPICZalpha and transformed into Pichia pastoris. Sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blotting, and in vitro lipid binding activity assay confirmed that the eight ns-LTP were all successfully expressed and capable of in vitro binding fatty acid molecules. A comparative in vitro study on the toxicity of eight wheat ns-LTP to mycelium growth or spore germination of eight wheat pathogens and three nonwheat pathogens revealed differential toxicities among different ns-LTP. Values indicating 50% inhibition of fungal growth or spore germination of three selected ns-LTP against six fungi ranged from 1 to 7 microM. In vitro lipid-binding activity of ns-LTP was not correlated with their antifungal activity. Using the fluorescent probe SYTOX Green as an indicator of fungal membrane integrity, the in vitro toxicity of wheat ns-LTP was associated with alteration in permeability of fungal membranes.

Genomic Identification and Comparative Expansion Analysis of the Non-Specific Lipid Transfer Protein Gene Family in Gossypium

“…Additionally, nsLTPs play an important role in the protective mechanisms against pathogens in plants. The nsLTPs from some plants have reported to show obvious antifungal activities against V. dahliae 24252627, we thus investigated the expression patterns of the nsLTPs in response to V. dahliae to take a further step towards understanding the function of cotton nsLTPs against V. dahliae . As displayed in Fig.…”

Plant pathogenesis-related (PR) proteins: A focus on PR peptides

“…Lipid transfer proteins (LTPs) are small, cationic, cysteine-rich peptides found in various plant species (reviews in [15,57,58,128], including barley [79], grapevine [40], wheat [97], A. thaliana and spinach [91] and onion [12]. Plant LTPs are sub-divided into two families, LTP1s and LTP2s, which present molecular masses of around 9 and 7 kDa, respectively.…”

Resistance to Fusarium verticillioides and fumonisin accumulation in maize inbred lines involves an earlier and enhanced expression of lipoxygenase (LOX) genes

“…Lipid Transfer Protein (LTPs) bind to and transfer lipids from membrane and have shown multiple roles in defence against pathogens, in cuticle synthesis and as modulators of plant growth and development (Yeats and Rose, 2008) and have been linked to F. graminearum resistance in wheat (Schweiger et al, 2013;Sun et al, 2008;Xiao et al, 2013). In our study, the expression profiles of two LTPs, namely phospholipase transfer protein homolog1 (Zmplt1) and lipid binding protein (ZmLBP) were analysed.…”