Stone formation in peach fruit exhibits spatial coordination of the lignin and flavonoid pathways and similarity to Arabidopsis dehiscence

<p>Abstract</p> <p>Background</p> <p>Lignification of the fruit endocarp layer occurs in many angiosperms and plays a critical role in seed protection and dispersal. This process has been extensively studied with relationship to pod shatter or dehiscence in <it>Arabidopsis</it>. Dehiscence is controlled by a set of transcription factors that define the fruit tissue layers and whether or not they lignify. In contrast, relatively little is known about similar processes in other plants such as stone fruits which contain an extremely hard lignified endocarp or stone surrounding a single seed.</p> <p>Results</p> <p>Here we show that lignin deposition in peach initiates near the blossom end within the endocarp layer and proceeds in a distinct spatial-temporal pattern. Microarray studies using a developmental series from young fruits identified a sharp and transient induction of phenylpropanoid, lignin and flavonoid pathway genes concurrent with lignification and subsequent stone hardening. Quantitative polymerase chain reaction studies revealed that specific phenylpropanoid (phenylalanine ammonia-lyase and cinnamate 4-hydroxylase) and lignin (caffeoyl-CoA O-methyltransferase, peroxidase and laccase) pathway genes were induced in the endocarp layer over a 10 day time period, while two lignin genes (<it>p-</it>coumarate 3-hydroxylase and cinnamoyl CoA reductase) were co-regulated with flavonoid pathway genes (chalcone synthase, dihydroflavanol 4-reductase, leucoanthocyanidin dioxygen-ase and flavanone-3-hydrosylase) which were mesocarp and exocarp specific. Analysis of other fruit development expression studies revealed that flavonoid pathway induction is conserved in the related Rosaceae species apple while lignin pathway induction is not. The transcription factor expression of peach genes homologous to known endocarp determinant genes in <it>Arabidopsis </it>including <it>SHATTERPROOF</it>, <it>SEEDSTCK </it>and <it>NAC SECONDARY WALL THICENING PROMOTING FACTOR 1 </it>were found to be specifically expressed in the endocarp while the negative regulator <it>FRUITFU</it>L predominated in exocarp and mesocarp.</p> <p>Conclusions</p> <p>Collectively, the data suggests, first, that the process of endocarp determination and differentiation in peach and <it>Arabidopsis </it>share common regulators and, secondly, reveals a previously unknown coordination of competing lignin and flavonoid biosynthetic pathways during early fruit development.</p

Proteomic Comparison of Fruit Ripening between ‘Hedelfinger’ Sweet Cherry (Prunus avium L.) and Its Somaclonal Variant ‘HS’

The somaclonal variant HS, from sweet cherry (Prunus avium L.) ‘Hedelfinger’ (H), was previously selected for reduced tree vegetative vigor and lesser canopy density. In this work, we compared H and HS fruits at early unripe (green) and full ripe (dark red) stages by biochemical and proteomic approaches. The main biochemical parameters showed that fruit quality was not affected by somaclonal variation. The proteomic analysis identified 39 proteins differentially accumulated between H and HS fruits at the two ripening stages, embracing enzymes involved in several pathways, such as carbon metabolism, cell wall modification, stress response, and secondary metabolism. The evaluation of fruit phenolic composition by mass spectrometry showed that HS sweet cherries have higher levels of procyanidin, flavonol, and anthocyanin compounds. This work provides the first proteomic characterization of fruit ripening in sweet cherry, revealing new positive traits of the HS somaclonal variant

Low diaphragm muscle mass predicts adverse outcome in patients hospitalized for COVID-19 pneumonia: An exploratory pilot study

BACKGROUND: The aim of this study was to evaluate whether measurement of diaphragm thickness (DT) by ultrasonography may be a clinically useful noninvasive method for identifying patients at risk of adverse outcomes defined as need of invasive mechanical ventilation or death. METHODS: We prospectively enrolled 77 patients with laboratory-confirmed COVID-19 infection admitted to our intermediate care unit in Pisa between March 5 and March 30, 2020, with follow-up until hospital discharge or death. Logistic regression was used identify variables potentially associated with adverse outcomes and those P&lt;0.10 were entered into a multivariate logistic regression model. cumulative probability for lack of adverse outcomes in patients with or without low baseline diaphragm muscle mass was calculated with the Kaplan-Meier product-limit estimator. RESULTS: The main findings of this study are that: 1) patients who developed adverse outcomes had thinner diaphragm than those who did not (2.0 vs. 2.2 mm, P=0.001); and 2) DT and lymphocyte count were independent significant predictors of adverse outcomes, with end-expiratory DT being the strongest (8=-708; oR=0.492; P=0.018). coNcLUSioNS: Diaphragmatic ultrasound may be a valid tool to evaluate the risk of respiratory failure. Evaluating the need of mechanical ventilation treatment should be based not only on Pao2/Fio2, but on a more comprehensive assess¬ ment including DT because if the lungs become less compliant a thinner diaphragm, albeit free of intrinsic abnormality, may become exhausted, thus contributing to severe respiratory failure