Research advances and prospects of legume lectins

Genome-wide identification and functional exploration of the legume lectin genes in Brassica napus and their roles in Sclerotinia disease resistance

“…Legume lectins were extensively distributed in the plant, and display a variety of functions including antimicrobial and insecticidal activities (Lagarda-Diaz et al, 2017;Katoch and Tripathi, 2021). Increasing evidence has suggested that insect and pathogen infestation of crops is one of the crucial factors threatening global agriculture production, whose impacts will further increase in the future due to increasing demand for food and changing climatic conditions (Fedoroff et al, 2010).…”

“…Hence, as potential candidates for resistance to susceptible crops, legume lectins are worth in-depth and extensive investigation. In the last two decades, much research attention has been paid to legume lectins that are weakly expressed in non-storage tissues (Katoch and Tripathi, 2021;Van Damme, 2022). It has been found that AtLecRK-V.5, AtLecRK-IX.2 and AtLecRK-I.9 contribute to plant resistance to P. syringae (Desclos-Theveniau et al, 2012;Balagué et al, 2017), and AtLecRK-VI.2 and AtLecRK-I.9 play important roles in plant immune response (Huang et al, 2014).…”

“…The BnLegLu genes containing the kinase domain in cluster III may respond to S. sclerotiorum through stress signal transduction (Bellande et al, 2017); while the four BnLegLus genes in cluster VI whose expression was induced by SD may recognize and respond to S. sclerotiorum hyphae as a function of classical lectins (De Coninck and Van Damme, 2021;Fonseca et al, 2022; Figure 2). Previous studies have shown that lectins can bind to hyphae, resulting in the swelling of hyphae, vacuolation of the cell content, destruction of the nutrient absorption of the fungi, interference with spore germination, and even cell wall lysis (Lagarda-Diaz et al, 2017;Katoch and Tripathi, 2021). Here, subcellular localization analysis revealed that BnLegLus-16 was localized on the cell membrane, and its overexpression enhanced SD resistance in tobacco (Figures 7C-E), which provides a causal gene contributing to SD resistance in the plant.…”

“…Biotic and abiotic stresses severely disrupt the homeostasis of the plant immune system and cause great negative effects on plant growth, development, and yield (Kosová et al, 2011). Plant lectins are widely distributed in nature, and play important roles in the plant immune system (Katoch and Tripathi, 2021). Numerous induced lectins and lectin receptor-like kinases have been reported to be involved in various stress responses (Van Damme, 2022).…”

“…Despite of the conserved primary, secondary and tertiary structure of the legume lectin domain, its quaternary structure shows considerable variations. Most classical legume lectins can form homodimers or homotetramers ("dimers of dimers"; Lagarda-Diaz et al, 2017), and the monomer structure displays a jelly-roll tertiary fold like a β-sandwich (a flattened six-stranded β-sheet and a curved seven-stranded β-sheet interconnected by several loops) of 25-30 kDa, which contains a carbohydrate recognition domain (CRD) and metal binding sites for divalent cations (Ca 2+ and Mn 2+ ; Gautam et al, 2018b;Katoch and Tripathi, 2021). One loop important for carbohydrate binding is highly variable, leading to changes in carbohydrate specificity (Katoch and Tripathi, 2021).…”