Comparative analysis of volatile compounds in different muskmelon cultivars in Xinjiang based on HS-SPME-GC-MS and transcriptomics

Volatile flavor has prompted a great amount of influence in acceptance and view points in fruit products.Melon(Pyrus communis)is an aromadense fruit,thus,the evaluation of volatile flavor is crucial to melon-breeding.The volatile compounds present in nine varieties of Xinjiang muskmelons were identified and analyzed using the headspace solid-phase microextraction and gas chromatography-mass spectrometry methods.In addition,transcriptomics were used to discover the differential genes in fatty acid degradation pathways.It was found that a total of 170 volatile substances,including 52 alcohols,41 esters,24 aldehydes,32 ketones,14 acids and seven phenols,were identified in the nine melons.Results of PCA showed that 3-nonanol,2-nonanol,bis(2-ethylhexyl)adipate,and 2-methylpropanal contributed more to the flavor of melon.It was verified that high activities of acyl-coenzyme A cholesterol acyltransferase(AAT)promoted the conversion of alcohols to esters,so that the melons have a high content of esters.Four genes of long-chain acyl-CoA synthetase were mainly responsible for the large difference in volatile substances.This practice may further undermine the primary rationale for the breeding and promotion in different cultivars of muskmelon.

Target classification using SIFT sequence scale invariants

On the basis of scale invariant feature transform（SIFT） descriptors,a novel kind of local invariants based on SIFT sequence scale（SIFT-SS） is proposed and applied to target classification.First of all,the merits of using an SIFT algorithm for target classification are discussed.Secondly,the scales of SIFT descriptors are sorted by descending as SIFT-SS,which is sent to a support vector machine（SVM） with radial based function（RBF） kernel in order to train SVM classifier,which will be used for achieving target classification.Experimental results indicate that the SIFT-SS algorithm is efficient for target classification and can obtain a higher recognition rate than affine moment invariants（AMI） and multi-scale auto-convolution（MSA） in some complex situations,such as the situation with the existence of noises and occlusions.Moreover,the computational time of SIFT-SS is shorter than MSA and longer than AMI.

A detached petal disc assay and virus-induced gene silencing facilitate the study of Botrytis cinerea resistance in rose flowers

Fresh-cut roses(Rosa hybrida)are one of the most important ornamental crops worldwide,with annual trade in the billions of dollars.Gray mold disease caused by the pathogen Botrytis cinerea is the most serious fungal threat to cut roses,causing extensive postharvest losses.In this study,we optimized a detached petal disc assay(DPDA)for artificial B.cinerea inoculation and quantification of disease symptoms in rose petals.Furthermore,as the identification of rose genes involved in B.cinerea resistance could provide useful genetic and genomic resources,we devised a virusinduced gene silencing(VIGS)procedure for the functional analysis of B.cinerea resistance genes in rose petals.We used RhPR10.1 as a reporter of silencing efficiency and found that the rose cultivar‘Samantha’showed the greatest decrease in RhPR10.1 expression among the cultivars tested.To determine whether jasmonic acid and ethylene are required for B.cinerea resistance in rose petals,we used VIGS to silence the expression of RhLOX5 and RhEIN3(encoding a jasmonic acid biosynthesis pathway protein and an ethylene regulatory protein,respectively)and found that petal susceptibility to B.cinerea was affected.Finally,a VIGS screen of B.cinerea-induced rose transcription factors demonstrated the potential benefits of this method for the high-throughput identification of gene function in B.cinerea resistance.Collectively,our data show that the combination of the DPDA and VIGS is a reliable and highthroughput method for studying B.cinerea resistance in rose.

Classification of New Biomarkers of Dilated Cardiomyopathy Based on Pathogenesis—An Update

Dilated Cardiomyopathy (DCM) is a complex heart disease affecting the heart musculature and vasculature, involving one or several underlying pathophysiological mechanisms. Identifying potential biomarkers for dilated cardiomyopathy is a challenge owing to various aetiologies involved. Studying the biomarkers involved in DCM will ultimately give a better insight about which pathophysiological pathways are involved in the onset of the disease. Owing to its multifactorial aetiologies, response to treatment is usually poor. If we can find the exact underlying causes, a better treatment approach could be implemented. One way to obtain better insight of DCM is to study the biomarkers released. Through biomarkers, we can know which underlying mechanisms are involved. Biomarkers can provide us with clinical information such as diagnostic, prognostic, risk stratification as well as response to treatment. Underlying mechanisms such as inflammation, stress/strain, myocyte injury, matrix remodelling, oxidative stress, neurohormones involvement, among others, can contribute to the onset of DCM. Different mechanisms will yield different biomarkers. So it would be wise to classify those biomarkers involving in DCM based on their respective pathogenesis. Moreover, most importantly is to be able to make use of the information that biomarker pertains. However, specificity of those biomarkers poses a problem. One way of making these biomarkers clinically useful is to make use of a biomarker modelling score system.

Research Progress of Cardiac Myosin Binding Protein C in Dilated Cardiomyopathy and Other Cardiac Conditions

Since its discovery, myosin-binding protein C (cMyBP-C) has become a protein of interest clinically. With emergence of new methodologies and technologies, the structure and functions of cMyBP-C from different aspects can be studied, enabling us to better understand its involvement in certain cardiac conditions. Studying its kinetics of release and clearance from the circulation and by comparing to other conventional biomarkers, it has been reported that cMyBP-C is eligible to be a novel biomarker for several cardiac conditions. Moreover, studying the genetics and their involvement in pathogenic mechanisms has opened the ideas for potential therapeutic strategies. More and more researches are constantly being done to better understand the role of cMyBP-C in dilated cardiomyopathy (DCM). The importance of cMyBP-C to the heart is still actively being investigated. Its presence is however crucial for sarcomere organization and proper regulation of cardiac contraction during systole and complete relaxation during diastole. Genetic mutation in cMyBP-C has been linked to cardiac conditions including hypertrophic and dilated cardiomyopathies. Around 350 types of mutations have already been documented leading to various cardiac conditions and abnormalities. Analyzing human heart samples has enabled us to better understand the importance of cMyBP-C and how its mutations lead to inherited cardiomyopathies. It is therefore necessary to have an update about the research progress of cMyBP-C in relation to DCM and other cardiac conditions.

Graft-accelerated virus-induced gene silencing facilitates functional genomics in rose flowers

Rose has emerged as a model ornamental plant for studies of flower development, senescence, and morphology, as well as the metabolism of floral fragrances and colors.Virus-induced gene silencing(VIGS) has long been used in functional genomics studies of rose by vacuum infiltration of cuttings or seedlings with an Agrobacterium suspension carrying TRV-derived vectors. However, VIGS in rose flowers remains a challenge because of its low efficiency and long time to establish silencing. Here we present a novel and rapid VIGS method that can be used to analyze gene function in rose,called ‘graft-accelerated VIGS’, where axil ary sprouts are cut from the rose plant and vacuum infiltrated with Agrobacterium. The inoculated scions are then grafted back onto the plants to flower and silencing phenotypes can be observed within 5 weeks, post-infiltration. Using this new method, we successfully silenced expression of the RhDFR, RhA G, and RhNUDXin rose flowers, and affected their color, petal number, as well as fragrance, respectively. This grafting method will facilitate high-throughput functional analysis of genes in rose flowers. Importantly, it may also be applied to other woody species that are not currently amenable to VIGS by conventional leaf or plantlet/seedling infiltration methods.