Sugar conundrum in plant-pathogen interactions: roles of invertase and sugar transporters depend on pathosystems.

It has been increasingly recognized that CWIN (cell wall invertase) and sugar transporters including STP (sugar transport protein) and SWEET (sugar will eventually be exported transporters) play important roles in plant-pathogen interactions. However, the information available in the literature comes from diverse systems and often yields contradictory findings and conclusions. To solve this puzzle, we provide here a comprehensive assessment of the topic. Our analyses revealed that the regulation of plant-microbe interactions by CWIN, SWEET, and STP is conditioned by the specific pathosystems involved. The roles of CWINs in plant resistance are largely determined by the lifestyle of pathogens (biotrophs versus necrotrophs or hemibiotrophs), possibly through CWIN-mediated salicylic acid or jasmonic acid signaling and programmed cell death pathways. The up-regulation of SWEETs and STPs may enhance or reduce plant resistance, depending on the cellular sites from which pathogens acquire sugars from the host cells. Finally, plants employ unique mechanisms to defend against viral infection, in part through a sugar-based regulation of plasmodesmatal development or aperture. Our appraisal further calls for attention to be paid to the involvement of microbial sugar metabolism and transport in plant-pathogen interactions, which is an integrated but overlooked component of such interactions.

The Validity of Two Neuromotor Assessments for Predicting Motor Performance at 12 Months in Preterm Infants.

OBJECTIVE: To evaluate the validity of the Test of Infant Motor Performance (TIMP) and general movements (GMs) assessment for predicting Alberta Infant Motor Scale (AIMS) score at 12 months in preterm infants. METHODS: A total of 44 preterm infants who underwent the GMs and TIMP at 1 month and 3 months of corrected age (CA) and whose motor performance was evaluated using AIMS at 12 months CA were included. GMs were judged as abnormal on basis of poor repertoire or cramped-synchronized movements at 1 month CA and abnormal or absent fidgety movement at 3 months CA. TIMP and AIMS scores were categorized as normal (average and low average and >5th percentile, respectively) or abnormal (below average and far below average or <5th percentile, respectively). Correlations between GMs and TIMP scores at 1 month and 3 months CA and the AIMS classification at 12 months CA were examined. RESULTS: The TIMP score at 3 months CA and GMs at 1 month and 3 months CA were significantly correlated with the motor performance at 12 months CA. However, the TIMP score at 1 month CA did not correlate with the AIMS classification at 12 months CA. For infants with normal GMs at 3 months CA, the TIMP score at 3 months CA correlated significantly with the AIMS classification at 12 months CA. CONCLUSION: Our findings suggest that neuromotor assessment using GMs and TIMP could be useful to identify preterm infants who are likely to benefit from intervention.

Associations Between Prolonged Intubation and Developing Post-extubation Dysphagia and Aspiration Pneumonia in Non-neurologic Critically Ill Patients.

OBJECTIVE: To identify the associations between the duration of endotracheal intubation and developing post-extubational supraglottic and infraglottic aspiration (PEA) and subsequent aspiration pneumonia. METHODS: This was a retrospective observational study from January 2009 to November 2014 of all adult patients who had non-neurologic critical illness, required endotracheal intubation and were referred for videofluoroscopic swallowing study. Demographic information, intensive care unit (ICU) admission diagnosis, severity of critical illness, duration of endotracheal intubation, length of stay in ICU, presence of PEA and severity of dysphagia were reviewed. RESULTS: Seventy-four patients were enrolled and their PEA frequency was 59%. Patients with PEA had significantly longer endotracheal intubation durations than did those without (median [interquartile range]: 15 [9-21] vs. 10 [6-15] days; p=0.02). In multivariate logistic regression analysis, the endotracheal intubation duration was significantly associated with PEA (odds ratio, 1.09; 95% confidence interval [CI], 1.01-1.18; p=0.04). Spearman correlation analysis of intubation duration and dysphagia severity showed a positive linear association (r=0.282, p=0.02). The areas under the receiver operating characteristic curves (AUCs) of endotracheal intubation duration for developing PEA and aspiration pneumonia were 0.665 (95% CI, 0.542-0.788; p=0.02) and 0.727 (95% CI, 0.614-0.840; p=0.001), respectively. CONCLUSION: In non-neurologic critically ill patients, the duration of endotracheal intubation was independently associated with PEA development. Additionally, the duration was positively correlated with dysphagia severity and may be helpful for identifying patients who require a swallowing evaluation after extubation.

Model-assisted physiological analysis of Phyllo, a rice architectural mutant.

Studies of phenotype of knockout mutants can provide new insights into physiological, phenological and architectural feedbacks in the plant system. Phyllo, a mutant of Nippon Bare rice (Oryza sativa L.) producing small leaves in rapid succession, was isolated during multiplication of a T-DNA insertion library. Phyllo phenotype was compared with the wild type (WT) during vegetative development in hydroponics culture using a wide range of physiological and biometric measurements. These were integrated with the help of the functional-structural model EcoMeristem, explicitly designed to study interactions between morphogenesis and carbon assimilation. Although the phenotype of the mutant was caused by a single recessive gene, it differed in many ways from the WT, suggesting a pleiotropic effect of this mutation. Phyllochron was 25 (1-4 leaf stage) to 38% (>>4 leaf stage) shorter but showed normal transition from juvenile to adult phase after leaf 4. Leaf size also increased steadily with leaf position as in WT. The mutant had reduced leaf blade length : width and blade : sheath length ratios, particularly during the transition from heterotrophic to autotrophic growth. During the same period, root : shoot dry weight ratio was significantly diminished. Specific leaf area (SLA) was strongly increased in the mutant but showed normal descending patterns with leaf position. Probably related to high SLA, the mutant had much lower light-saturated leaf photosynthetic rates and lower radiation use efficiency (RUE) than the WT. Leaf extension rates were strongly reduced in absolute terms but were high in relative terms (normalised by final leaf length). The application of the EcoMeristem model to these data indicated that the mutant was severely deficient in assimilate, resulting from low RUE and high organ initiation rate causing high assimilate demand. This was particularly pronounced during the heterotrophic-autotrophic transition, probably causing shorter leaf blades relative to sheaths, as well as a temporary reduction of assimilate partitioning to roots. The model accurately simulated the mutant's high leaf mortality and absence of tillering. The simulated assimilate shortage was supported by observed reductions in starch storage in sheaths. Soluble sugar concentrations differed between mutant and WT in roots but not in shoots. Specifically, the hexose : sucrose ratio was 50% lower in the roots of the mutant, possibly indicating low invertase activity. Furthermore, two OsCIN genes coding for cell wall invertases were not expressed in roots, and others were expressed weakly. This was interpreted as natural silencing via sugar signalling. In summary, the authors attributed the majority of observed allometric and metabolic modifications in the mutant to an extreme assimilate shortage caused by hastened shoot organogenesis and inefficient leaf morphology.