Overexpression of a wheat jasmonate-regulated lectin increases pathogen resistance

Abstract

Jasmonates are known to induce the transcriptional activation of plant defense genes, which leads to the production of jasmonate-regulated proteins (JRP). We previously cloned and characterized a novel jacalin-like lectin gene (Ta-JA1) from wheat (Triticum aestivum L.), which codes a modular JRP with disease response and jacalin-related lectin (JRL) domains and is present only in the Gramineae family. The function of this protein is still unclear. Phylogenetic analysis indicated that Ta-JA1 and related proteins from cereals grouped together, which diverged from JRL with an additional N-terminal disease response domain. The recombinant Ta-JA1 proteins agglutinated rabbit erythrocytes, and this hemagglutination activity was preferentially inhibited by mannose. The Ta-JA1 protein was able to inhibit E. coli cell growth. Overexpression of Ta-JA1 in transgenic tobacco plants increased their resistance to infection by tobacco bacterial, fungal and viral pathogens. Our results suggest that Ta-JA1 belongs to a mannose-specific lectin, which may confer a basal but broad-spectrum resistance to plant pathogens. Ta-JA1 and its homologues in maize, rice, sorghum and creeping bentgrass may represent a new type of monocot lectin with a modular structure and diversity of physiological functions in biotic and abiotic stress responses.

Laticifers in mulberry exclusively accumulate defense proteins related to biotic stresses

“…They were all possible defense proteins against insects or microorganisms ( Kitajima and Sato 1999;Ma et al 2010;Subramanyam et al 2008;van Loon et al 2006), which is consistent with the idea that laticifers are specialized for defense against biotic stresses (Kitajima et al 2010(Kitajima et al , 2012Konno 2011). In the unlignified tissue laticifers, one of the galactosebinding lectins (bands 6 and 7) and PR-1 (band 11) were Figure 1.…”

Comparative study of gene expression and major proteins’ function of laticifers in lignified and unlignified organs of mulberry

“…In petiole laticifer, the highest rank was an isogroup of the LA-a/LA-b gene family, accounting for 6.3% of total reads, with over five times that of the second-ranked transcript. The isogroups of the top 20% of total reads contained, in addition to the LA-a/ LA-b gene family, various possible antimicrobial/insecticidal proteins: jacalin-like lectin (Subramanyam et al 2008;Ma et al 2010) and pathogenesis-related (PR) proteins such as peroxidase, class I chitinase, b-1,3-glucanase, and thaumatin-like protein (for review see van Loon et al 2006). High accumulation of these proteins supports the idea that the laticifer is a specialized cell for defense against biotic stresses (Konno et al 2004;Wasano et al 2009;Kitajima et al 2010; for review see Konno 2011).…”

Lectins and Their Roles in Pests Control

“…Table 1. Plant lectins with oral toxicity to insects (Adapted from Vasconcelos et al, 2004) decades, important progress has been made in the study of the activity of plant lectins against pathogens, nematodes and especially insect pests (Ma et al, 2010;Peumans and Van Damme, 1995;Vasconcelos and Oliveira, 2004). The best-characterized family of plants lectins are Fabaceae, Poaceae and Solanaceae; especially some of leguminous seeds have a remarkable amount of lectin.…”