Molecular characterization and expression analysis of pitaya (Hylocereus polyrhizus) HpLRR genes in response to Neoscytalidium dimidiatum infection

Abstract

Background: Canker disease caused by Neoscytalidium dimidiatum is a devastating disease resulting in a major loss to the pitaya industry. However, resistance proteins in plants play crucial roles to against pathogen infection. Among resistance proteins, the leucine-rich repeat (LRR) protein is a major family that plays crucial roles in plant growth, development, and biotic and abiotic stress responses, especially in disease defense. Results: In the present study, a transcriptomics analysis identified a total of 272 LRR genes, 233 of which had coding sequences (CDSs), in the plant pitaya (Hylocereus polyrhizus) in response to fungal Neoscytalidium dimidiatum infection. These genes were divided into various subgroups based on specific domains and phylogenetic analysis. Molecular characterization, functional annotation of proteins, and an expression analysis of the LRR genes were conducted. Additionally, four LRR genes (CL445.Contig4_All, Unigene28_All, CL28.Contig2_All, and Unigene2712_All, which were selected because they had the four longest CDSs were further assessed using quantitative reverse transcription PCR (qRT-PCR) at different fungal infection stages in different pitaya species (Hylocereus polyrhizus and Hylocereus undatus), in different pitaya tissues, and after treatment with salicylic acid (SA), methyl jasmonate (MeJA), and abscisic acid (ABA) hormones. The associated protein functions and roles in signaling pathways were identified. Conclusions: This study provides a comprehensive overview of the HpLRR family genes at transcriptional level in pitaya in response to N. dimidiatum infection, it will be helpful to understand the molecular mechanism of pitaya canker disease, and lay a strong foundation for further research.

Host-pathogen interaction between pitaya and Neoscytalidium dimidiatum reveals the mechanisms of immune response associated with defense regulators and metabolic pathways

“…Data analysis was performed using the 2 −ΔΔCt method. The ubiquitin gene of pitaya [ 51 ] and the tubulin gene of N. dimidiatum [ 5 ] served as the internal reference genes. SPSS v19.0 (SPSS, Chicago, IL, USA) was used to conduct a one-way analysis of variance (ANOVA) with Duncan’s multiple range post hoc test, and there was a significance threshold of p < 0.05.…”

Advances in the Understanding of Postharvest Physiological Changes and the Storage and Preservation of Pitaya

“…Activation of PAL, 4CL, POD, and PPO by 10 mM β-aminobutyric acid (BABA) promoted phenolic, flavonoid, and lignin accumulation, effectively preventing pitaya fruit postharvest decay [120]. The combination of methyl jasmonate and gibberellin with chitosan was found to delay the postharvest color change in pitaya, maintain its original color, delay the reduction in vitamin C, and maintain its soluble solids content [121].…”

Plant-Associated Neoscytalidium dimidiatum—Taxonomy, Host Range, Epidemiology, Virulence, and Management Strategies: A Comprehensive Review

“…The interactions between this pathogen and its host plants are multifaceted and not fully elucidated [181]. Moreover, the virulence mechanisms employed by N. dimidiatum are still being explored.…”

“…Moreover, investigations into host-pathogen interactions have identified key genes associated with plant defense responses and calcium ion signaling pathways in red-fleshed pitaya [181,200]. These studies emphasize the potential roles of specific genes, including PR homologous proteins and WRKY transcription factors, in regulating pitaya's defense mechanisms against N. dimidiatum infection.…”