Comparative transcriptome analysis of stylar canal cells identifies novel candidate genes implicated in the self-incompatibility response of Citrus clementina

<p>Abstract</p> <p>Background</p> <p>Reproductive biology in citrus is still poorly understood. Although in recent years several efforts have been made to study pollen-pistil interaction and self-incompatibility, little information is available about the molecular mechanisms regulating these processes. Here we report the identification of candidate genes involved in pollen-pistil interaction and self-incompatibility in clementine (<it>Citrus clementina </it>Hort. ex Tan.). These genes have been identified comparing the transcriptomes of laser-microdissected stylar canal cells (SCC) isolated from two genotypes differing for self-incompatibility response ('Comune', a self-incompatible cultivar and 'Monreal', a self- compatible mutation of 'Comune').</p> <p>Results</p> <p>The transcriptome profiling of SCC indicated that the differential regulation of few specific, mostly uncharacterized transcripts is associated with the breakdown of self-incompatibility in 'Monreal'. Among them, a novel F-box gene showed a drastic up-regulation both in laser microdissected stylar canal cells and in self-pollinated whole styles with stigmas of 'Comune' in concomitance with the arrest of pollen tube growth. Moreover, we identify a non-characterized gene family as closely associated to the self-incompatibility genetic program activated in 'Comune'. Three different aspartic-acid rich (Asp-rich) protein genes, located in tandem in the clementine genome, were over-represented in the transcriptome of 'Comune'. These genes are tightly linked to a DELLA gene, previously found to be up-regulated in the self-incompatible genotype during pollen-pistil interaction.</p> <p>Conclusion</p> <p>The highly specific transcriptome survey of the stylar canal cells identified novel genes which have not been previously associated with self-pollen rejection in citrus and in other plant species. Bioinformatic and transcriptional analyses suggested that the mutation leading to self-compatibility in 'Monreal' affected the expression of non-homologous genes located in a restricted genome region. Also, we hypothesize that the Asp-rich protein genes may act as Ca²⁺"entrapping" proteins, potentially regulating Ca²⁺homeostasis during self-pollen recognition.</p

Impact of periodontal microRNAs associated with alveolar bone remodeling during orthodontic tooth movement: a randomized clinical trial

Background-Micro-RNAs (miRNAs) have been reported to play an important role during orthodontic tooth movement (OTM) through the regulation of periodontal soft and hard tissue homeostasis and functions. The aim of the present study was to assess the effects of miRNAs on OTM and to evaluate possible predictors that influenced the overall OTM amount at a 3-month follow-up. Methods-Through a split-mouth design, 21 healthy patients (mean age 13.2 ± 1.8 years) were enrolled in the present study. Clinical parameters and gingival crevicular fluid (GCF) sampling were performed on both compression and tension sides of a random canine to be distalized (test groups) at baseline and at 1 h, 1 day, 1 month and at 3-month after OTM, while the contralateral canine served as a control group. miRNAs − 7a-3p, -7a-2-3p, -7a-5p, -21-3p, -21-5p, -100-3p, -100-5p, -125b-2-3p, -125b-5p, -200b-3p, and − 200b-5p expression was analyzed using a real-time quantitative polymerase chain reaction (RT-PCR). Data were analyzed to assess miRNAs change following OTM. Spearman test, two-way ANOVA and a multivariate regression model were established to evaluate the correlation among miRNAs and clinical parameters and to explore possible predictors of OTM amount at 3-month follow-up. Results-At 3-month follow-up, there was an increase of miRNA-7a-2-3p, -21-5p, -100-5p, a decrease of miRNA-125b-5p, 200b-3p and − 200b-5p in the compression side and an increase of miRNA-7a-3p, 100-5p in the tension side (p &lt; 0.05). The two-way ANOVA revealed that OTM determined, on the compression side, a significant upregulation on miRNA-7a-3p (p = 0.017), -7a-2-3p (p = 0.023), -21-5p (p = 0.007), -100-5p (p = 0.025) and a significant downregulation of miRNA-125b-2-3p (p = 0.019) and − 200b-5p (p = 0.017). The multivariate model highlighted that high baseline miRNA-7a2-3p (p = 0.025), -21-5p (p = 0.014), -200b-3p (p = 0.041), young age (p = 0.042), lower bleeding on probing (BOP) (p = 0.021) and miRNA-125b-2-3p (p = 0.021) levels were significant predictors of OTM at 3-month follow-up. Conclusions-In the present study, OTM significantly impacted the expression of the miRNAs analyzed, in both the tension and compression side of traction tooth at 3-month follow-up. High baseline miRNA-7a2-3p, -21-5p, -200b-3p, and lower miRNA-125b-2-3p, together with younger age and lower BOP, were significant predictors of OTM amount at 3-month follow-up. Trial registration-ClinicalTrials.gov NCT06023433 (retrospectively registered)

QTL analysis on a lemon population provides novel insights on the genetic regulation of the tolerance to the two-spotted spider mite attack

Background: Among the Citrus species, lemon (Citrus limon Burm f.) is one of the most affected by the two-spotted spider mite (Tetranychus urticae Koch). Moreover, chemical control is hampered by the mite's ability to develop genetic resistance against acaricides. In this context, the identification of the genetic basis of the host resistance could represent a sustainable strategy for spider mite control. In the present study, a marker-trait association analysis was performed on a lemon population employing an association mapping approach. An inter-specific full-sib population composed of 109 accessions was phenotyped through a detached-leaf assays performed in modified Huffaker cells. Those individuals, complemented with two inter-specific segregating populations, were genotyped using a target-sequencing approach called SPET (Single Primer Enrichment Technology), the resulting SNPs were employed for the generation of an integrated genetic map. Results: The percentage of damaged area in the full-sib population showed a quantitative distribution with values ranging from 0.36 to 9.67%. A total of 47,298 SNPs were selected for an association mapping study and a significant marker linked with resistance to spider mite was detected on linkage group 5. In silico gene annotation of the QTL interval enabled the detection of 13 genes involved in immune response to biotic and abiotic stress. Gene expression analysis showed an over expression of the gene encoding for the ethylene-responsive transcription factor ERF098-like, already characterized in Arabidopsis and in rice for its involvement in defense response. Conclusion: The identification of a molecular marker linked to the resistance to spider mite attack can pave the way for the development of marker-assisted breeding plan for the development of novel selection coupling favorable agronomical traits (e.g. fruit quality, yield) with a higher resistance toward the mit

Effects of combined respiratory physiotherapy with high-flow nasal cannula and Venturi mask in spinal cord injury: a single-subject research study and literature review

Background: The level of spinal cord injury affects the severity of respiratory impairment and the alteration of respiratory pattern and gas exchanges. Lesions at the C3-C5 level (phrenic nerve nucleus) cause disruption of descending input with paralysis of the main inspiratory muscle, often requiring tracheostomy and prolonged mechanical ventilation. Oxygen therapy is essential to switch from ventilatory support to removal of the endotracheal tube to correct residual difficulties in oxygenation management. Case Presentation: A 58-year-old man had tracheostomy and tetraparesis as complication of tonsillectomy and adenoidectomy treatment for a history of obstructive sleep apnea. A respiratory rehabilitation program with protocol of oxygen therapy with high flow cannula alternated with a low-flow system by Venturi mask during daytime hours only was started. The patient was constantly monitored with capillary partial oxygen saturation to obtain adequate oxygenation (> 94%) and registered every 15 minutes in the clinical chart. There was gradual improvement of respiratory function. Oxygen by Venturi mask was gradually reduced due to improvement of partial pressure oxygen values. Over the course of days, the optimal results of respiratory parameters led to a gradual weaning from the Venturi mask until the complete discontinuation of the low-flow system during daytime and decreased of the high-flow fraction of inspired oxygen to the maximal tolerated level during nighttime. Conclusions: Implementing a combined protocol of nighttime oxygen with high flow cannula and daytime Venturi mask improves intensive motor training of patients by promoting the acquisition of ability to perform chair/bed transitions and to be able to achieve standing and begin gait training. More research is needed whether or noted to determine the role of this promising approach in patients with severe SCI and in other critically ill patients

Exploring additive and non-additive genetic models to decipher the genetic regulation of almond tolerance to Diaporthe amygdali

Constriction canker (Diaporthe amygdali) is one of the main diseases affecting almond cultivation. To unravel the genetic basis of the tolerance to the disease, a germplasm collection of 123 almond accessions (111 selected in Sicily, Italy, complemented with widely cultivated Italian and International varieties), was employed for a Genome-Wide Association Study (GWAS). Accessions were phenotyped employing a detached-twig inoculation assay, here employed for the first time for a GWAS, ensuring high throughputness and reproducibility. The most susceptible and tolerant accessions were also inoculated in planta and the two phenotyping methods showed a significant correlation of 0.7. Genotyping was performed using the Axiom™ 60K almond array, resulting in the identification of 47,496 robust markers. Both additive and non-additive GWAS models were tested leading to the identification of nine SNPs significantly associated with tolerance to D. amygdali. Candidate genes in linkage-disequilibrium with the significant SNPs were functionally characterized and a subset of 20 were further validated through RT-qPCR in both the most tolerant (the Sicilian ‘Cuti’) and susceptible (‘Ferraduel’) genotypes at 0 and at 2 days after in planta inoculations. The results provide novel insights to understand the genetic regulation of the tolerance to D. amygdali and for the set-up of marker-assisted selection plans in almond

Expression of clementine asp-rich proteins (CcASP-RICH) in tobacco plants interferes with the mechanism of pollen tube growth

Low-molecular-weight, aspartic-acid-rich proteins (ASP-RICH) have been assumed to be involved in the self-incompatibility process of clementine. The role of ASP-RICH is not known, but hypothetically they could sequester calcium ions (Ca2+) and affect Ca2+-dependent mechanisms. In this article, we analyzed the effects induced by clementine ASP-RICH proteins (CcASP-RICH) when expressed in the tobacco heterologous system, focusing on the male gametophyte. The aim was to gain insight into the mechanism of action of ASP-RICH in a well-known cellular system, i.e., the pollen tube. Pollen tubes of tobacco transgenic lines expressing CcASP-RICH were analyzed for Ca2+ distribution, ROS, proton gradient, as well as cytoskeleton and cell wall. CcASP-RICH modulated Ca2+ content and consequently affected cytoskeleton organization and the deposition of cell wall components. In turn, this affected the growth pattern of pollen tubes. Although the expression of CcASP-RICH did not exert a remarkable effect on the growth rate of pollen tubes, effects at the level of growth pattern suggest that the expression of ASP-RICH may exert a regulatory action on the mechanism of plant cell growth

The PLATO mission

PLATO (PLAnetary Transits and Oscillations of stars) is ESA’s M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2REarth) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5%, 10%, 10% for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO‘s target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile towards the end of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases