Using FIBexDB for In-Depth Analysis of Flax Lectin Gene Expression in Response to Fusarium oxysporum Infection

Plant proteins with lectin domains play an essential role in plant immunity modulation, but among a plurality of lectins recruited by plants, only a few members have been functionally characterized. For the analysis of flax lectin gene expression, we used FIBexDB, which includes an efficient algorithm for flax gene expression analysis combining gene clustering and coexpression network analysis. We analyzed the lectin gene expression in various flax tissues, including root tips infected with Fusarium oxysporum. Two pools of lectin genes were revealed: downregulated and upregulated during the infection. Lectins with suppressed gene expression are associated with protein biosynthesis (Calreticulin family), cell wall biosynthesis (galactose-binding lectin family) and cytoskeleton functioning (Malectin family). Among the upregulated lectin genes were those encoding lectins from the Hevein, Nictaba, and GNA families. The main participants from each group are discussed. A list of lectin genes, the expression of which can determine the resistance of flax, is proposed, for example, the genes encoding amaranthins. We demonstrate that FIBexDB is an efficient tool both for the visualization of data, and for searching for the general patterns of lectin genes that may play an essential role in normal plant development and defense.

Differential regulation of degradation and immune pathways underlies adaptation of the symbiotic nematode Laxus oneistus to oxic-anoxic interfaces

Eukaryotes may experience oxygen deprivation under both physiological and pathological conditions. Because oxygen shortage leads to a reduction in cellular energy production, all eukaryotes studied so far conserve energy by suppressing their metabolism. However, the molecular physiology of animals that naturally and repeatedly experience anoxia underexplored. One such animal is the symbiotic marine nematode Laxus oneistus. It thrives, invariably coated by its sulfur-oxidizing bacterium Candidatus Thiosymbion oneisti, in anoxic sulfidic or hypoxic sand. Here, transcriptomics and proteomics showed that, whether in anoxia or not, L. oneistus mostly expressed genes involved in ubiquitination, energy generation, oxidative stress response, immune response, development, and translation. Importantly, ubiquitination genes were also highly expressed when the nematode was subjected to anoxic sulfidic conditions, together with genes involved in autophagy, detoxification, chaperone-encoding genes, and ribosome biogenesis. We hypothesize that these degradation pathways were induced to recycle damaged cellular components (mitochondria) and misfolded proteins into nutrients. Remarkably, when L. oneistus was subjected to anoxic sulfidic conditions, lectin genes were also upregulated, potentially to promote the attachment of its thiotrophic anaerobic symbiont. Furthermore, L. oneistus appeared to survive oxygen deprivation by using an alternative electron carrier (rhodoquinone) and acceptor (fumarate), to rewire the electron transfer chain. On the other hand, under hypoxia, genes involved in costly processes (e.g., amino acid biosynthesis, development, feeding, mating) were upregulated, together with the worm's Toll-like innate immunity pathway and several immune effectors (e.g., Bacterial Permeability Increasing proteins, fungicides). In conclusion, we hypothesize that, in anoxic sulfidic sand, L. oneistus survives by overexpressing degradation processes, rewiring oxidative phosphorylation and by reinforcing its coat of bacterial sulfur-oxidizers. In upper sand layers, instead, it appears to produce broad-range antimicrobials and to exploit oxygen for biosynthesis and development.

Genome-wide Identification and Characterization of G-type lectin in Fragaria Vesca

Background: Lectins make up a large and diverse group of proteins in plants. G-type lectins are important type of lectins involved in plant development and defense process. However, studies about G-type lectins are limited to lectin receptor kinases.Results: In this study, genome-wide identification was carried out on G-type lectin gene family in Fragaria vesca. A total of 133 genes were found belonging to this family and they were classified into four groups: G-type lectin receptor kinases, G-type lectin kinases, G-type lectin receptor proteins and G-type lectin proteins, according to their domain organizations. Their chromosome localization, phylogenetic and evolutionary relationship were also analyzed. The results showed that tandem and dispersed duplication occurred frequently, which led to the expansion of G-type lectin gene family in F. vesca and may have increased the types of domain arrangement. The expression profile of G-type lectin genes at different developmental stages of F. vesca and under various biotic/abiotic stresses was inferred from the available databases. G-type lectin genes are actively expressed during F. vesca development and respond to multiple biotic/abiotic stresses. Additionally, to comprehend the functions of G-type lectins, we predicted strawberry genes that may co-express with these G-type lectin genes. Conclusions: G-type lectin gene family is a large gene family in F. vesca. Domain organization and expression analysis imply their functions under biotic/abiotic stresses.

Resident and elicited macrophages differ in expression of their glycomes and lectins

The pleiotropic functions of macrophages in immune defense, tissue repair, and maintenance of tissue homeostasis are supported by the heterogeneity in macrophage sub-populations that differ both in ontogeny and polarization. Although glycans and lectins are integral to macrophage function, little is known about the factors governing their expression. Here we show that the cellular glycome of murine peritoneal macrophages primarily reflects developmental origin and to a lesser degree, cellular polarization. Resident macrophages were characterized by a simple glycome, predominantly consisting of core 1 O-glycans, while elicited macrophages also expressed core 2 O-glycans, along with highly branched and extended complex-type N-glycans, that exhibited a higher N-acetylneuraminic acid:N-glycolylneuraminic acid ratio. Strikingly, our analysis revealed that resident and elicited macrophages express 139 lectin genes, with differential expression of 49 lectin genes, including galectins, Siglecs, and C-type lectins. These results suggest that regulation of self-glycan-protein complexes may be central to macrophage residence and recruitment.

Signaling through plant lectins: modulation of plant immunity and beyond

Lectins constitute an abundant group of proteins that are present throughout the plant kingdom. Only recently, genome-wide screenings have unraveled the multitude of different lectin sequences within one plant species. It appears that plants employ a plurality of lectins, though relatively few lectins have already been studied and functionally characterized. Therefore, it is very likely that the full potential of lectin genes in plants is underrated. This review summarizes the knowledge of plasma membrane-bound lectins in different biological processes (such as recognition of pathogen-derived molecules and symbiosis) and illustrates the significance of soluble intracellular lectins and how they can contribute to plant signaling. Altogether, the family of plant lectins is highly complex with an enormous diversity in biochemical properties and activities.

In silico identification and characterlization of the lectin gene families in cassava (Manihot esculenta Crantz)

Plant lectins, a superfamily of glycan-binding proteins, play important roles in various biological processes, including plant defense and cell signaling. Until now, little or no research has been carried out on lectins in cassava (Manihot esculenta Crantz); a prime food, feed and bio-energy crop in the tropics to sub-tropics. In this study, we identified 5 homologous genes encoding class V chitinases (CRA) and 17 genes encoding hevein (Hvi) domains in total and annotated them in the cassava genome. The large size of MeCRA and MeHvi genes possibly resulted from tandem duplication events, directly linked to the expansion of CRA and hevein gene families. Phylogenetic analysis showed 3 distinct groups of hevein genes with their typical gene organization. The most common motif of gene structure of MeCRA family was recorded to be 2 exons/1 intron. Promoter analysis revealed that most of the members of lectin gene families are assumed to be responsive to light conditions and are expressed in specific for particular organs or plant tissues. The presence of hormonal- and/or stress-responsive elements in the promoter regions of all lectin genes indicated their involvement in the crop’s stress response and plant signaling. Since most members of CRA and hevein family were strongly expressed in various major tissues/organs, products of those lectin genes may play important roles in the development of cassava plants, especially in plant defense system. Citation: Chu Duc Ha, Wyckhuys K. A. G., Le Tien Dung, 2017. In silico identification and characterlization of the lectin gene families in cassava (Manihot esculenta Crantz). Tap chi Sinh hoc, 39(3): 320-332. DOI: 10.15625/0866-7160/v39n3.9185 *Corresponding author: [email protected]; [email protected] Received 25 January 2017, accepted 20 August 2017