Systematic Characterization of GATA Transcription Factors in Liriodendron chinense and Functional Validation in Abiotic Stresses

Characterization, evolution, and abiotic stress responses of leucine-rich repeat receptor-like protein kinases (LRR-RLK) in Liriodendron chinense

BACKGROUND

Liriodendron chinense is susceptible to extinction due to the increasing severity of abiotic stresses resulting from global climate change, consequently impacting its growth, development, and geographic distribution. However, the L. chinense remains pivotal in both socio-economic and ecological realms. The LRR-RLK (leucine-rich repeat receptor-like protein kinase) genes, constituting a substantial cluster of receptor-like kinases in plants, are crucial for plant growth and stress regulation and are unexplored in the L. chinense.

RESULT

233 LchiLRR-RLK genes were discovered, unevenly distributed across 17 chromosomes and 24 contigs. Among these, 67 pairs of paralogous genes demonstrated gene linkages, facilitating the expansion of the LchiLRR-RLK gene family through tandem (35.82%) and segmental (64.18%) duplications. The synonymous and nonsynonymous ratios showed that the LchiLRR-RLK genes underwent a purifying or stabilizing selection during evolution. Investigations in the conserved domain and protein structures revealed that the LchiLRR-RLKs are highly conserved, carrying conserved protein kinase and leucine-rich repeat-like domians that promote clustering in different groups implicating gene evolutionary conservation. A deeper analysis of LchiLRR-RLK full protein sequences phylogeny showed 13 groups with a common ancestor protein. Interspecies gene collinearity showed more orthologous gene pairs between L. chinense and P. trichocarpa, suggesting various similar biological functions between the two plant species. Analysis of the functional roles of the LchiLRR-RLK genes using the qPCR demonstrated that they are involved in cold, heat, and salt stress regulation, especially, members of subgroups VIII, III, and Xa.

CONCLUSION

Conclusively, the LRR-RLK genes are conserved in L. chinense and function to regulate the temperature and salt stresses, and this research provides new insights into understanding LchiLRR-RLK genes and their regulatory effects in abiotic stresses.

Genome-Wide Identification and Expression Analysis of GATA Family Genes in Dimocarpus longan Lour

GATA transcription factors, which are DNA-binding proteins with type IV zinc finger binding domains, have a role in transcriptional regulation in biological organisms. They have an indispensable role in the growth and development of plants, as well as in improvements in their ability to face various environmental stresses. To date, GATAs have been identified in many gene families, but the GATA gene in longan (Dimocarpus longan Lour) has not been studied in previous explorations. Various aspects of genes in the longan GATA family, including their identification and classification, the distribution of their positions on chromosomes, their exon/intron structures, a synteny analysis, their expression at different temperatures, concentration of PEG, early developmental stages of somatic embryos and their expression levels in different tissues, and concentrations of exogenous hormones, were investigated in this study. This study showed that the 22 DlGATAs could be divided into four subfamilies. There were 10 pairs of homologous GATA genes in the synteny analysis of DlGATA and AtGATA. Four segmental replication motifs and one pair of tandem duplication events were present among the DlGATA family members. The cis-acting elements located in promoter regions were also found to be enriched with light-responsive elements, which contained related hormone-responsive elements. In somatic embryos, DlGATA4 is upregulated for expression at the globular embryo (GE) stage. We also found that DlGATA expression was strongly up-regulated in roots and stems. The study demonstrated the expression of DlGATA under hormone (ABA and IAA) treatments in embryogenic callus of longan. Under ABA treatment, DlGATA4 was up-regulated and the other DlGATA genes did not respond significantly. Moreover, as demonstrated with qRT-PCR, the expression of DlGATA genes showed strong up-regulated expression levels under 100 μmol·L-1 concentration IAA treatment. This experiment further studied these and simulated their possible connections with a drought response mechanism, while correlating them with their expression under PEG treatment. Overall, this experiment explored the GATA genes and dug into their evolution, structure, function, and expression profile, thus providing more information for a more in-depth study of the characteristics of the GATA family of genes.