Identification and functional analysis ofLecRLKgenes inTaxodium‘Zhongshanshan’

Abstract

Background Lectin receptor-like protein kinases (LecRLKs) can transform external stimuli into intracellular signals and play important regulatory roles in plant development and response to environmental stressors. However, research on the LecRLK gene family of conifers has seldom been reported. Methods Putative LecRLK genes were identified in the transcriptome of Taxodium ‘Zhongshanshan’. The classification, domain structures, subcellular localization prediction, and expression patterns of LecRLK genes, as well as co-expressed genes, were analyzed using bioinformatics methods. Fifteen representative genes were further selected for qRT-PCR analysis in six tissues and under five different environmental stressor conditions. Results In total, 297 LecRLK genes were identified, including 155 G-type, 140 L-type, and 2 C-type. According to the classification, G-type and L-type LecRLK genes both can be organized into seven groups. The domain architecture of G-type proteins were more complex compared with that of L- and C-type proteins. Conservative motifs were found in G-type and L-type diverse lectin domains. Prediction and transient expression experiments to determine subcellular localization showed that LecRLKs were mainly concentrated in the cell membrane system, and some members were located at multiple sites at the same time. RNA-seq-based transcriptomics analysis suggested functional redundancy and divergence within each group. Unigenes co-expressed with LecRLKs in the transcriptome were found to be enriched in pathways related to signal transduction and environmental adaptation. Furthermore, qRT-PCR analysis of representative genes showed evidence of functional divergence between different groups. Conclusions This is the first study to conduct an identification and expression analysis of the LecRLK gene family in Taxodium. These results provide a basis for future studies on the evolution and function of this important gene family in Taxodium.

Identification of LecRLK gene family in Cerasus humilis through genomic-transcriptomic data mining and expression analyses

“…In C. humilis, the amplification of the chLecRLK gene family is mainly caused by gene tandem duplications and therefore promotes their evolution. It is worth noting that G-type LecRLKs have been more evolutionary expanded compared to L-type chLecRLKs, which is in agreements with the findings on LecRLK gene family evolution of potato, Taxodium, tomato, pear and Populus [2,11,14].…”

“…Among 125 G-type chLecRLKs, 46 family members have only one exon while the rest have at least 4 exons. Most L-type chLecRLKs have one exon (29 out of 43), and the chLecRLK-L34 gene has the most exons (11).…”

“…Membrane localized receptor-like kinases (RLKs), together with other signal receptors like phytochromes, act as the first site of signal perception, which allows the plants to communicate between cells and to respond to changes in their environment [1,2]. Lectin receptor-like protein kinase (LecRLK) family is a group of RLKs that have been shown to play several vital roles in plant pathogenic defense, symbiotic association, insect feeding response, innate immunity and different abiotic stress responses, such as low temperature and high salinity [3][4][5][6][7][8][9][10][11][12][13][14]. LecRLKs were firstly discover and examined in Arabidopsis thaliana [15], and were later isolated in a few important food crops, such as Oryza sativa [16], Pisum sativum [17], Solanum lycopersicum [10], Pyrus bretschneideri [2] and Solanum tuberosum [14].…”

Genome-Wide Identification and Characterization of Lectin Receptor-Like Kinase Gene Family in Cucumber and Expression Profiling Analysis under Different Treatments

“…Cell-surface receptors, a kind of signal receptor proteins, play important roles in receiving and transmitting environmental signals. The receptor-like kinase (RLK) family, one important family of cell surface receptors, contains three domains, such as the extracellular domain, transmembrane domain (TM) and intracellular kinase domain [1]. RLK proteins could be classified into different families based on the structure of the extracellular domains [2].…”

“…Lectin receptor-like kinases (LecRLKs), a class of RLKs that contain a lectin domain within the extracellular domain [1], are a gene family that is specialized for sensing external environmental stimuli and transmitting signals. They are localized on the cell membrane, relying on N terminus diverse extracellular ligand recognition domains (also called lectin domain) to recognize various environmental stimuli, and then phosphorylate downstream proteins through their C terminus intracellular kinase domain to pass on received signals [1,3].…”