Trends of Land Use and Land Cover Change in the Savannah Ecological of the Protected Area Reserve Partielle de Dosso, Niger

Information on the dynamics of savannah is important to a country's plan to overcome the problems of uncontrolled development and environmental hazards. Taking the reserve partielle de Dosso, Niger as the case study area, this paper analyzed the long-term land use land cover change from 2002 to 2022. Satellite images were processed by using Google Earth Engine (GEE). Therefore, four major land cover classes were identified based on spectral characteristics of Land sat, namely, built-up, vegetation, cropland, bare land and water. The result revealed that barren and built-up areas increased at the expense of vegetation and water. From the four major land use land cover the large area is covered by vegetation which comprises about 192963.5 hectares followed by cropland and water consisting of 32506.43 and 1596.4 hectares respectively. The built-up area gained substantial area (most) during the study period. The reduction in some of the land cover/uses underlines the dangerous trend of the pressure poised by population growth and the changing functionality. Land cover change is influenced by a variety of societal factors operating on several spatial and temporal levels. The area estimates and spatial distributions of the LULC classes produced from the current study will assist local authorities, managers, and other stakeholders in decision-making and planning regarding forest land cover and uses.

Multichannel imaging for monitoring chemical composition and germination capacity of cowpea(Vigna unguiculata) seeds during development and maturation

This study aimed to set a computer-integrated multichannel spectral imaging system as a high-throughput phenotyping tool for the analysis of individual cowpea seeds harvested at different developmental stages. The changes in germination capacity and variations in moisture, protein and different sugars during twelve stages of seed development from 10 to 32 days after anthesis were nondestructively monitored. Multispectral data at 20 discrete wavelengths in the ultraviolet, visible and near infrared regions were extracted from individual seeds and then modelled using partial least squares regression and linear discriminant analysis(LDA) models. The developed multivariate models were accurate enough for monitoring all possible changes occurred in moisture, protein and sugar contents with coefficients of determination in prediction R^(2) of 0.93, 0.80 and 0.78 and root mean square errors in prediction(RMSEP) of 6.045%, 2.236% and 0.890%, respectively. The accuracy of PLS models in predicting individual sugars such as verbascose and stachyose was reasonable with R~2 of 0.87 and 0.87 and RMSEP of 0.071%and 0.485%, respectively;but for the prediction of sucrose and raffinose the accuracy was relatively limited with R^(2) of 0.24 and 0.66 and RMSEP of 0.567% and 0.045%, respectively. The developed LDA model was robust in classifying the seeds based on their germination capacity with overall correct classification of96.33% and 95.67% in the training and validation datasets, respectively. With these levels of accuracy,the proposed multichannel spectral imaging system designed for single seeds could be an effective choice as a rapid screening and non-destructive technique for identifying the ideal harvesting time of cowpea seeds based on their chemical composition and germination capacity. Moreover, the development of chemical images of the major constituents along with classification images confirmed the usefulness of the proposed technique as a non-destructive tool for estimating the concentrations and spatial distributions of moisture, protein and sugars during different developmental stages of cowpea seeds.

Phenological stage effect on phenolic composition and repellent potential of Mentha pulegium against Tribolium castaneum and Lasioderma serricorne

Objective:To elucidate for the first time the phenological stage effect on polyphenol,flavonoid and proanthocyanidin contents of pennyroyal(Mentha pulegium)as well as their antioxidant capacities and insecticidal potentials against Tribolium castaneum and Lasioderma serricorne.Methods:Crude methanol extracts from pennyroyal(Mentha pulegium)aerial parts were evaluated for their anti radical,reducing power activities and repellent potentials against selected coleopteran insects during different phenological stages.Results:Phenolic contents of pennyroyal aerial parts and their antioxidant effects were significantly dependent on maturity stage of the plant.The maximum of phenol production was reached during the full flowering stage.Apigenin was the major phenol in Mentha pulegium with an amount of6.01 mg/g of dry vegetable matter during this period.Nevertheless,at fructification stage,the highest antioxidant activity was not related to high phenolic content.The repulsive effect of pennyroyal extract showed that Lasioderma serricorne was more susceptible to pennyroyal extract than Tribolium castarneum with corresponding median repellent dose values of 0.124and 0.006 mg/mL respectively.Moreover,great differences in insect repulsion depending on extract concentrations,exposure time and developmental stage was observed.For the lowest concentration(0.125 mg/mL),the repellent effect against Tribolium reached its maximum(90%)during the fructification stage(after 24 h of exposure)while this repellent effect was 80%during the vegetative stage.Conclusions:Due to the strong insecticidal potential of pennyroyal extracts,this study highlights the therapeutic properties of this plant and encourages its use as a safer,environmental-friendly and efficient insecticide in food industry.

In-Vitro Evaluation of Resistance to Late Blight (Phytophthora infestans Mont. De Bary.) in Solanum Accessions Native to Chile, by Inoculation of Detached Leaflets

The objective of the present study was to evaluate the resistance of 10 accessions to P. infestans, by in-vitro inoculation of detached leaflets with a complex isolation of the fungus. Late blight, caused by the fungus Phytophthora infestans Mont. De Bary, is one of the most important diseases of the potato crop, and can destroy complete plantations in a short space of time. Chile is considered as a sub-centre of the origin of cultivated potatoes with many native potato varieties in the country. The different resistance components demonstrated that within the material of Chilean native Solanum, there was a wide range of variation to late blight. The resistant control (R-8906384) and the accessions UCT-34-Cor presented the lowest infection efficiency, small sizes of the lesions and low levels of sporulation classifying them as the most resistant. This suggests low efficiency of the infection and high resistance to penetration in these materials. The more susceptible accessions often presented a good level of resistance for one or few components. It would be of great interest to go into the genetic control of the different resistance components to know if the same level of resistance expressed for a component by different accessions is under the same genetic control or not.

Inventory of Host Plants and Parasitoids of the Fall Armyworm (FAW), Spodoptera frugiperda (JE Smith), in the Southern Agricultural Zone of Niger

The fall armyworm, Spodoptera frugiperda (JE Smith), is a polyphagous pest reported in sub-Saharan Africa since 2016 and has expanded rapidly in almost Africa. In Niger, Spodoptera frugiperda (JE Smith) is considered like a major pest of maize, to which it causes significant damage, in a context where proven control methods against this moth remain almost non-existent. The objective of the present study was to determine the economic importance of FAW through the damage caused to the different host plants and to identify the parasitoids of this caterpillar. The study was conducted in the southern agricultural zone of Niger, specifically in the regions of Dosso, Maradi, Tahoua and Zinder. FAW eggs and caterpillars were collected from six villages in each region and then incubated and reared in the entomology laboratory of INRAN in Maradi. The rate of infestation of the different crops by FAW was determined as well as the observation of the beneficiaries. The results obtained indicate the presence of FAW on millet with an attack rate varying from 45.7% to 68%, sorghum with 47.2% to 62.25% and sesame with 9.7%. This work also revealed an oophagous parasitoid, Telenomus remus with 138 ± 23 and larval parasitoids, Cotesia sp with 16 ± 1 maximum number of individuals emerged from the collected material. Also, it was identified the parasitoid Cotesia icipe with a rate of parasitism from 4.6% to 5.75%;the Charops ater whose rate of parasitism varies from 4.5% and 12.25% but for Chelonus insularis with 17.25% and Tachnidae with 53%. These very interesting results will constitute a basis for the development of biological control and a component of an agroecological management strategy of caterpillar.

Emerging roles of lactic acid bacteria in protection against colorectal cancer

Colorectal cancer(CRC)is the third leading cause of cancer deaths worldwide and the fourth most common cancer diagnosed among men and women in the United States.Considering the risk factors of CRC,dietary therapy has become one of the most effective approaches in reducing CRC morbidity and mortality.The use of probiotics is increasing in popularity for both the prevention and treatment of a variety of diseases.As the most common types of microbes used as probiotics,lactic acid bacteria(LAB)are comprised of an ecologically diverse group of microorganisms united by formation of lactic acid as the primary metabolite of sugar metabolism.LAB have been successfully used in managing diarrhea,food allergies,and inflammatory bowel disease.LAB also demonstrated a host of properties in preventing colorectal cancer development by inhibiting initiation or progression through multiple pathways.In this review,we discuss recent insights into cellular and molecular mechanisms of LAB in CRC prevention including apoptosis,antioxidant DNA damages,immune responses,and epigenetics.The emerging experimental findings from clinical trials as well as the proposed mechanisms of gut microbiota in carcinogenesis will also be briefly discussed.

Dimensions of hepatocellular carcinoma phenotypic diversity

Hepatocellular carcinoma(HCC) is the 3^(rd) leading cause of cancer-related death worldwide. More than 80% of HCCs arise within chronic liver disease resulting from viral hepatitis, alcohol, hemochromatosis, obesity and metabolic syndrome or genotoxins. Projections based on Western lifestyle and its metabolic consequences anticipate a further increase in incidence, despite recent breakthroughs in the management of viral hepatitis. HCCs display high heterogeneity of molecular phenotypes, which challenges clinical management. However, emerging molecular classifications of HCCs have not yet formed a unified corpus translatable to the clinical practice. Thus, patient management is currently based upon tumor number, size, vascular invasion, performance status and functional liver reserve. Nonetheless, an impressive body of molecular evidence emerged within the last 20 years and is becoming increasingly available to medical practitioners and researchers in the form of repositories. Therefore, the aim this work is to review molecular data underlying HCC classifications and to organize this corpus into the major dimensions explaining HCC phenotypic diversity. Major efforts have been recently made worldwide toward a unifying "clinically-friendly" molecular landscape. As a result, a consensus emerges on three major dimensions explaining the HCC heterogeneity. In the first dimension, tumor cell proliferation and differentiation enabled allocation of HCCs to two major classes presenting profoundly different clinical aggressiveness. In the second dimension, HCC microenvironment and tumor immunity underlie recent therapeutic breakthroughs prolonging patients' survival. In the third dimension,metabolic reprogramming, with the recent emergence of subclass-specific metabolic profiles, may lead to adaptive and combined therapeutic approaches. Therefore, here we review recent molecular evidence, their impact on tumor histopathological features and clinical behavior and highlight the remaining challenges to translate our cognitive corpus into patient diagnosis and allocation to therapeutic options.

Biomass production and carbon balance in two hybrid poplar(Populus euramericana)plantations raised with and without agriculture in southern France

Poplar is useful in different climates for bioenergy production and carbon sequestration when planted as a single species or in agroforestry. Europe has large areas potentially suitable for poplar forestry and a bioenergy policy that would encourage poplar forestry. In this study I estimated biomass production and carbon sequestration in poplar monoculture plantation and poplar-wheat agroforestry, in the Mediterranean region of France. A single-tree harvesting method was used to estimate biomass and an empirical conversion factor was adopted to calculate sequestered carbon. Total biomass was higher in agroforestry trees(1223 kg tree) than in monoculture plantation trees(1102 kg tree).Aboveground and belowground biomass distributions were similar in both cases(89 and 88% aboveground, and 11 and12% belowground, respectively in agroforestry and monoculture). The partitioning of total biomass in an agroforestry tree in leaves, branch, and trunk(aboveground), and fine roots, medium roots, coarse roots and underground stem(belowground) was 1,22,and 77,and 6,9, 44 and 40%,respectively. Except for branch and trunk, all other compartments were similarly distributed in a monoculture tree.Storage of C was higher in agroforestry trees(612 kg tree)than in monoculture trees(512 kg tree). In contrast, C storage on a per hectare basis was lower in agroforestry(85 Mg ha) than in monoculture(105 Mg ha) due to the lower density of trees per hectare in agroforestry(139 trees in agroforestry vs 204 trees in monoculture). On a per hectare basis, soil C stocks pattern were similar to per tree stocking:They were higher in agroforestry at 330 Mg hathan in monoculture 304 Mg ha. Higher C accumulation by agroforestry has a direct management implication in the sense that expanding agroforestry into agriculture production areas with short rotation and fast growing trees like poplar would encourage quicker and greater C sequestration. This could simultaneously fulfil the requirement of bioenergy plantation in Europe.

Individual Leaf Area of Early Flowering Arabidopsis Genotypes Is More Affected by Drought than Late Flowering Ones: A Multi-Scale Analysis in 35 Genetically Modified Lines

Plants acclimate to drought optimizing the trade-off between biomass production and water loss while ensuring their survival and reproduction. Plants also modify their growth or phenology as complementary strategies in response to stress. Despite evidence of an interaction between flowering time and plant growth response to environmental stresses, this interaction in response to drought is under debate. To contribute to the analysis of this interaction, leaf growth of 35 genetically modified lines of Arabidopsis thaliana and their common wild-type, Col-0 was analyzed by a quantitative multi-scale phenotyping approach from cellular to whole plant scale both in well-watered and soil moderate water deficit conditions. These genotypes were selected for the various physiological functions potentially altered by their genetic modification and that could interact with plant growth and/or their drought responses. In all genotypes, leaf expansion decreased in response to drought both at the whole rosette and the individual leaf levels. Additionally, epidermal cell area and/or epidermal cell number decreased in response to the drought treatment. In contrast, the number of rosette leaves was reduced in only half of the genotypes and leaf growth duration was only modified in 4 of them. Despite long photoperiod conditions, the duration of the vegetative phase, i.e. the time elapsed between germination and flowering stage, varied from 12 to 27 days among genotypes under well watered conditions. Our analyses revealed that the differences of flowering time observed in well-watered condition impacted the leaf area response to drought. Early-flowering genotypes slightly decreased their final leaf number, but strongly reduced their individual leaf area compared with the late-flowering ones. This result underlines the difficulty to analyze plant response to environmental stresses when genotypes with different flowering dates are compared.

Genome mapping of postzygotic hybrid necrosis in an interspecific pear population

Deleterious epistatic interactions in plant inter-and intraspecific hybrids can cause a phenomenon known as hybrid necrosis,characterized by a typical seedling phenotype whose main distinguishing features are dwarfism,tissue necrosis and in some cases lethality.Identification of the chromosome regions associated with this type of incompatibility is important not only to increase our understanding of the evolutionary diversification that led to speciation but also for breeding purposes.Development of molecular markers linked to the lethal genes will allow breeders to avoid incompatible inbred combinations that could affect the expression of important agronomic tratis co-segregating with these genes.Although hybrid necrosis has been reported in several plant taxa,including Rosaceae species,this phenomenon has not been described previously in pear.In the interspecific pear population resulting from a cross between PEAR3(Pyrus bretschneideri×Pyrus communis)and‘Moonglow’(P.communis),we observed two types of hybrid necrosis,expressed at different stages of plant development.Using a combination of previously mapped and newly developed genetic markers,we identified three chromosome regions associated with these two types of lethality,which were genetically independent.One type resulted from a negative epistatic interaction between a locus on linkage group 5(LG5)of PEAR3 and a locus on LG1 of‘Moonglow’,while the second type was due to a gene that maps to LG2 of PEAR3 and which either acts alone or more probably interacts with another gene of unknown location inherited from‘Moonglow’.

Effect of low-density lipoproteins, spermatozoa concentration and glycerol on functional and motility parameters of bull spermatozoa during storage at 4℃

An extender has been developed with low-density lipoproteins （LDLs） that eliminates the microbial risks associated with the use of whole egg yolk. The objective of this study was to assess the effects of substituting egg yolk with LDLs for use as an extender in sperm preservation at 4 ℃, as well as on spermatozoa motility, plasma membrane and acrosome integrity, at two different concentrations （80×10^6 and 240× 10^6 sperm per ml） for 8 days and to evaluate glycerol toxicity in both extenders. A total of 12 ejaculates were collected from three bulls. Spermatozoa motility was examined using computer-assisted semen analysis. Plasma membrane integrity was determined using the hypo-osmotic swelling test and acrosome integrity with the fluorescein isothiocyanate-Pisum sativum agglutinin test. The semen was subsequently divided into four aliquots and diluted with Tris-egg yolk-glycerol （TEG）, Tris-egg yolk without glycerol （TE）, LDL with glycerol （LDL＋） and LDL without glycerol （LDL-）, at 80×10^6 and 240 ×10^6sperm per ml. This study showed that the LDL＋ and LDL- extenders were more effective at preserving spermatozoa motility, plasma membrane integrity and acrosome integrity than TEG and TE （P〈0.05） during 8 days of incubation. After 3 days of incubation, a toxicity of glycerol was observed in TEG, whereas no significant difference was observed between LDL＋ and LDL-. We can therefore conclude that the LDL extender can be used to refrigerate semen at 4 ~C instead of TEG and TE at 80×10^6and 240×10^6 sperm per ml for elite bulls. This finding can be used to define a policy for the storage of high-quality bull semen.

Modelling Operational Decision-Making in Agriculture

Farm management practices differ considerably among farmers. In this article, we explore the processes which farmers go through when making operational decisions about technical interventions. Because farmers have different approaches to the decision-making process, it is essential to describe these differences to identify areas in which management skills require improvement. This study identifies and represents contextual, informational and inferential aspects of the cognitive work a farm manager performs in operational decision-making. We developed a conceptual modelling framework that structures the decision-making behaviour along a set of cognitive processes such as perception, interpretation, goal reasoning, planning and judgment. These processes are activated repeatedly throughout the production process. The framework can help characterize variation in management behaviour and performance, and identify promising directions for improvement.

Technological Valorization of Algerian Dates Downgraded from <i>Deglet Nour</i>Variety to Semi-Candied Dates in Dates Syrup

The objective of this study is the valorization of downgraded dates from a high Algerian date variety Deglet Nour, locally called “h’chef”. The work starts with the implementation of a food formulation of semi-candied dates in syrup extracted from dates. This formulation was based on dehydration-impregnation by immersion (D.I.I.). The downgraded dates were cleaned, cut, blanched, and then immersed in date syrups with increasing differential concentrations in Brix degrees: 65°, 70° and 75°. The chosen date/syrup immersion ratio is 1:2 (w/w). The obtained semi-candied dates were the subject of physicochemical and sensory analyses. The characterization of the downgraded dates before immersion showed high sugar content with a rate 52.67 g% g of dry matter and low water content (14%) which favors their use in semi-candied products. The physico-chemical analyses results of the three semi-candied dates products show an increase in their final sugar content, i.e. from 53.55% to 60.78% and in ashes between 1.76 p.cent and 1.94 p.cent. On the other hand, sensory analysis results confirm that the semi-candied dates with a syrup of 75° Brix present the most appreciated and preferable organoleptic characteristics than the other variables. Finally, following appertisation, the stability test reveals good microbiological quality (100°C for 20 minutes) of the three (3) semi-candied formulations of dates. Thus, the valorization of the “h’chef” as sorting gap Deglet Nour date allowed its transformation into semi-candied dates, stable, appreciable on the organoleptic side. This new formulation could constitute a value-added product if eventually manufactured on an industrial scale, mainly in southern Algeria.

Farmer Participatory Evaluation of Sorghum Hybrid in Niger

Participatory varietal selection (PVS) with farmers and Seed Companies was conducted at Maradi research station (07°05'E/13°48'N) and in farmer field to evaluate and select sorghum hybrid varieties for high yield and other important agronomic traits. The experimental design was a randomized complete block with three replications where flowering (days), plant height (cm) and yield (kg) were collected. The analysis of variance showed highly significance among treatments of all traits measured Environment and Genotype by Environment interactions also contributed significantly to the performance of yield components. The highest average grain yield was recorded from hybrids P9511A x ST9007-5-2-1 (4289 kg/ha), NE223A x 90SN1 (3666 kg/ha), NE223A x Sepon 82 (3533 kg/ha) and NE223A x P9405 (3519 kg/ha) across locations. Farmers’ preferences were the panicle size, good seed set, earliness, and seed color. Hence, in a variety selection farmer’s preferences focus more on prioritized yield-related trait. The best varieties ranked by traits of interest were P9511A x ST9007-5-2-1, NE223A x 90SN1, NE223A x P9405 and P9511A x SEPON 82 that performed well under their circumstances. The results showed that farmers’ preferred varieties match with researchers. Therefore, based on objectively measured traits, farmers’ preferences and the agro ecologies of the site, varieties NE223A x 90SN1 and P9511A x ST9007-5-2-1 were found promising for production.

应用Le Bissonnais法研究黄土丘陵区土壤团聚体稳定性

以黄土丘陵区森林草原过渡带燕沟流域植被自然恢复过程中6种植被类型为研究对象,应用Le Bissonnais(LB)法测定了不同植被类型下土壤水稳性团聚体,对比分析了LB法3种处理的测定结果与传统湿筛法(Yoder)的差异性。结果表明:在LB法3种湿润处理下,快速湿润处理(FW)对土壤团聚体结构的破坏程度最大,处理后土壤水稳性团聚体以0.05～0.5 mm为主;慢速湿润处理(SW)对团聚体的破坏程度最小,处理后土壤水稳性团聚体主要以>2 mm团聚体为主;而预湿后扰动处理(WS)对团聚体的破坏程度介于FW和SW之间,处理后土壤团聚体粒径分布比较均匀。说明该区土壤团聚体破坏的主要机制是土壤孔隙中的气泡爆破产生的消散作用。退耕100a期间,植被群落由1年生草本(4 a)—多年生灌草(16 a)—半灌木(29 a)—灌木(55 a)—乔木(100 a)方向演替过程中,土壤水稳性团聚体由小粒径向大粒径方向转变,土壤结构趋于稳定。LB法3种处理中,FW处理与SW处理所测得>0.5 mm团聚体含量和平均重量直径与土壤有机质和物理性黏粒之间存在显著的相关性,而WS处理未达到显著水平(P>0.05)。说明土壤有机质和物理性黏粒主要影响消散和黏粒膨胀引起的崩解作用,而对机械干扰引起的团聚体破坏无明显影响。LB法3种处理中,慢速湿润方法所获得土壤团聚体稳定性特征更接近湿筛法,适宜于黄土丘陵区植被恢复过程中土壤水稳性团聚体的测定。

Efficacy and safety profile of LCR35 complete freeze-dried culture in irritable bowel syndrome:A randomized,double-blind study

AIM:To assess the effects and safety of Lactobacillus casei rhamnosus LCR35 complete freeze-dried culture(LCR35) in patients suffering from irritable bowel syndrome(IBS).METHODS:A randomized,double-blind pilot study was performed in 50 patients complaining of IBS symptoms complying with RomeⅢcriteria.Patients were allocated to receive either LCR35(n = 25) at a minimum daily dose of 6 × 108 colony forming units or placebo(n = 25) for 4 wk.At inclusion,after treatment and 2 wk later,patients completed the IBS severity scale.Change from baseline in the IBS severity score at the end of treatment was the primary efficacy criterion.Changes were compared between groups in the whole population and in IBS subtypes(IBS with predominance of constipation,IBS with predominance of diarrhoea,mixed IBS,unsubtyped IBS).The presence of lactobacillus casei rhamnosus in stools was investigated at inclusion and at the end of treatment.The gastrointestinal quality of life questionnaire and the hospital anxiety and depression(HAD) scale were also completed.RESULTS:Both groups were balanced for baseline characteristics.In 85% of patients,stool analyses showed that lactobacillus casei rhamnosus able to survive in the digestive tract.In the whole population,improvements in the IBS severity score did not differ significantly between treatments with a 25% decrease after 4-wk treatment,and a 15% decrease from baseline 2 wk later in both groups.In IBS subgroups,statistical analysis could not be performed due to small sample size,but a clinical response in favour of LCR35 was observed in IBS patients with predominance of diarrhoea:no change in the symptom severity score was seen with the placebo after 4 wk treatment,whereas a clinically relevant decrease occurred with LCR35(-37% vs-3%).Furthermore,in spite of an increase in symptom intensity,the IBS severity score was maintained below the baseline value 2 wk later with LCR35(-19% from baseline),whilst a slight 5% increase from baseline was observed with placebo.In the IBS subgroup with predominance of diarrhoea only,a clinically relevant decrease in abdominal pain severity score(-36%)was observed with LCR35,whereas no change occurred with placebo.In mixed IBS patients,the 20% and 30% decreases in the IBS severity score observed after treatment with LCR35 and placebo,respectively,were maintained 2 wk later in both groups.A clinical response slightly in favour of placebo was observed at the end of the treatment period in IBS patients with predominance of constipation(-41% vs-20%) and unsubtyped IBS patients(-47% vs-17%),with the same value maintained 2 wk later.In both groups,no clinically relevant changes were observed either for the gastrointestinal quality of life index or HAD score.Thus,these results suggest that sub-grouping of IBS patients may be important for optimizing treatment responses by the physician.CONCLUSION:This pilot study suggests that LCR35 could have some efficacy in IBS patients complaining of diarrhoea.These preliminary results need to be conf irmed in larger studies.

Nuclearly Encoded Splicing Factors Implicated in RNA Splicing in Higher Plant Organelles

Plant organelles arose from two independent endosymbiosis events. Throughout evolutionary history, tight control of chloroplasts and mitochondria has been gained by the nucleus, which regulates most steps of organelle genome expression and metabolism. In particular, RNA maturation, including RNA splicing, is highly dependent on nuclearly encoded splicing factors. Most introns in organelles are group II introns, whose catalytic mechanism closely resembles that of the nuclear spliceosome. Plant group II introns have lost the ability to self-splice in vivo and require nuclearly encoded proteins as cofactors. Since the first splicing factor was identified in chloroplasts more than 10 years ago, many other proteins have been shown to be involved in splicing of one or more introns in chloroplasts or mitochondria. These new proteins belong to a variety of different families of RNA binding proteins and provide new insights into ribonucleoprotein complexes and RNA splicing machineries in organelles. In this review, we describe how splicing factors, encoded by the nucleus and targeted to the organelles, take part in post-transcriptional steps in higher plant organelle gene expression. We go on to discuss the potential for these factors to regulate organelle gene expression.

Apple whole genome sequences:recent advances and new prospects

In 2010,a major scientific milestone was achieved for tree fruit crops:publication of the first draft whole genome sequence(WGS)for apple(Malus domestica).This WGS,v1.0,was valuable as the initial reference for sequence information,fine mapping,gene discovery,variant discovery,and tool development.A new,high quality apple WGS,GDDH13 v1.1,was released in 2017 and now serves as the reference genome for apple.Over the past decade,these apple WGSs have had an enormous impact on our understanding of apple biological functioning,trait physiology and inheritance,leading to practical applications for improving this highly valued crop.Causal gene identities for phenotypes of fundamental and practical interest can today be discovered much more rapidly.Genome-wide polymorphisms at high genetic resolution are screened efficiently over hundreds to thousands of individuals with new insights into genetic relationships and pedigrees.High-density genetic maps are constructed efficiently and quantitative trait loci for valuable traits are readily associated with positional candidate genes and/or converted into diagnostic tests for breeders.We understand the species,geographical,and genomic origins of domesticated apple more precisely,as well as its relationship to wild relatives.The WGS has turbo-charged application of these classical research steps to crop improvement and drives innovative methods to achieve more durable,environmentally sound,productive,and consumer-desirable apple production.This review includes examples of basic and practical breakthroughs and challenges in using the apple WGSs.Recommendations for“what’s next”focus on necessary upgrades to the genome sequence data pool,as well as for use of the data,to reach new frontiers in genomics-based scientific understanding of apple.