BSA-seq-based identification of a major additive plant height QTL with an effect equivalent to that of Semi-dwarf 1 in a large rice F_(2) population

Bulked-segregant analysis is a time-and cost-saving strategy for identifying major quantitative trait loci(QTL) in a mapping population. Bulked-segregant analysis combined with whole-genome sequencing(BSA-seq) was performed to rapidly identify QTL for heading date, plant height, and panicle length in a large F_(2) population derived from two landraces: Chuan 7(C7) and Haoboka(HBK). Twenty plants with extremely low or high phenotypic values for the target traits were selected from an F_(2) population of 940 plants to construct low-and high-value bulks. Three pairs of bulks for the three traits were constructed, resulting in six DNA pools. BSA-seq revealed nine QTL: four for heading date, three for plant height, and two for panicle length. These QTL were validated in a random F_(2) population or BC_(4)F_(2) populations. The major novel plant height QTL, qPH8, acting additively with an effect equivalent to that of semi-dwarf 1(sd1), is potentially valuable for hybrid rice breeding. qPH8 controls mainly the elongation of basal internodes. The C7 allele of qPH8 reduces plant height and increases lodging resistance without yield penalty, suggesting a potential role for qPH8 in improving rice plant architecture.

Caraway as Important Medicinal Plants in Management of Diseases

Carum carvi or caraway is traditionally used for treatment of indigestion,pneumonia,and as appetizer,galactagogue,and carminative.Essential oil,fixed oil and many other valuable extractive compounds with industrial applications are prepared from caraway.This review article has new deep research on caraway as medicinal plant.For preparing the manuscript,the information was extracted from accessible international databases(Google scholar,PubMed,Science direct,Springer,and Wiley),electronic resources and traditional books by key word of caraway or Carum carvi.The results of traditional studies exhibited that the galactagogue and carminative effects of caraway fruits are superior to other effects.Although,the traditional scholars used it as appetizer,while caraway was the main ingredient of anti-obesity drugs in traditional medicine,which has been confirmed in two modern clinical trials of human studies.Caraway oil in combination with peppermint oil or menthol is used for treatment of functional dyspepsia in clinical studies.Caraway oil topically on abdomen relieves the IBS symptoms in patient.Although,the use of caraway oil is not recommended in adults under 18 years due to insufficient data,but it can topically use as anti-colic and carminative agent in children or infants.The antiaflatoxigenic,antioxidant and antimicrobial effects of caraway oil along with its reputation as spice help the industries to use it as natural preservatives and antioxidant agents.

Antioxidant activity and total phenolic content of essential oils and extracts of sweet basil(Ocimum basilicum L.)plants

The present study was conducted to evaluate the chemical composition and antioxidant activity of the essential oils and ethanol extracts of Ocimum basilicum L.obtained from Assiut,Minia and BeniSuef of Egypt.The major constituents of sweet basil essential oils from three locations were linalool,estragole,methyl cinnamate,bicyclosesquiphellandrene,eucalyptol,-bergamotene,eugenol,-cadinene and germacrene D by the method of GC–MS.The relative concentration of these compounds varies.The basil extracts contained appreciable levels of total phenolic contents and exhibited good DPPH radical scavenging capacity higher than that of essential oils.The highest TPC(82.45 mg PE/g)and maximum radical scavenging activity with IC50 value(1.29 mg/mL)was obtained from Minia basil extract.High correlation between antioxidant activity and total phenolic contents of basil extracts was observed.High variation in free radical scavenging activity of essential oils was found.The essential oil from Minia basil showed high activity in DPPH radical scavenging with IC50(11.23 mg/mL)and contained the highest content of phenolic(41.3 mg PE/g).On contrary,low correlation between antioxidant activity and total phenolic contents of basil essential oils from different locations.The results of the present investigation demonstrated significant variations in the antioxidant activities of sweet basil essential oils and extracts from Egypt.

Ampelographic and Genetic Diversity Assessment of Some Local Grape Genotypes under Egyptian Conditions

Grape (Vitis vinifera L.) is assumed as one of the most valuable and popular fruit crops all over the world. In this study, ten of local grape germplasm were characterized considering phenotypic diversity and genetic features under Egyptian conditions. Selected local grapes;Baltim Eswid, Edkawy, Matrouh Eswid, Bez El-Naka, Bez El-Anza, Romy Abiad, Romy Ahmer, Gharibi, Fayoumi and Banaty, were spread geographically among seven national governorates. A total of 58 attributes were characterized grape germplasm for the distinctness of vine parts. For molecular characterization, 9 nuclear SSR loci were analysed. Data revealed a broad sense of similarity at the level of studied morphological attributes, where the highest similarity (0.93) was between Romy Ahmer and Romy Abiad. A total of 24 alleles, ranging from 124 - 253 bp in size, were detected at the nine tested loci with an average of 2.67 alleles per locus. The amplification products in all of the 9 SSRs loci showed polymorphism among the 10 grapevine cultivars. The genetic relatedness among most of the cultivars was in accordance with their identification based on ampelographic properties. Data of phenotypic and molecular analysis revealed high variability of Vitis germplasm in Egypt and contributed substantially to our awareness of valuable local grape genetic resources which are on the verge of extinction.

Effect of Alternate Bearing Phenomenon and Boron Foliar Application on Nitrogen-15 Uptake,Translocation and Distribution in Mango Tree(cv.Zebda)

The objectives of this investigation are to study nitrogen uptake,translocation,accumulation and distribution in mango tree organs using labeled nitrogen(^(15)N)and to understand the mechanism of boron action in increasing fruit yield in the off-year.A field experiment was conducted using fifteen-year-old mango trees(cv.Zebda)grown at Al Malak Valley Farm,El-Sharkeya Governorate-Egypt.Treatments included the application of(^(15)NH4)2SO4,“in the on-year”,at a rate of 50 g nitrogen/tree through the stem injection technique.While boron was sprayed on the same trees“in the off-year”at the following rates:0.0(control),250 and 500 mg·L^(-1).The authors hypothesize that boron and nitrogen act synergistically to increase mango fruit yield in the off-year.Results indicated that the highest ^(15)N uptake and accumulation in the on and off-years was observed in the upper(young leaves).When boron was applied at 250 mg·L^(-1),in the off-year,the upper(young leaves)recorded the highest ^(15)N uptake and accumulation(%^(15)Ndff=13.93)relative to the other two leaf categories and those of the on-year.In the on-year fruit accumulated higher ^(15)N than leaf or bud.In the off-year,bud exhibited the highest ^(15)N accumulation without boron application,while leaves exhibited the highest ^(15)N with boron application.The highest%^(15)Ndff in all tree organs was observed at 250 mg·L^(-1) boron rate.Boron increased nitrogen uptake,translocation and accumulation in mango tree organs.A synergistic relationship was observed between boron and nitrogen which led to an increase in fruit yield in the off-year.

A review:the mechanism of plant-derived polysaccharides on osteoblasts and osteoclasts

Bone loss and deterioration of bone microarchitecture would increase the bone fragility and fracture risk,leading to the osteoporosis.More and more evidences proved that plant-derived polysaccharides could have a remarkable influence on osteoblasts and osteoclasts,exerting anti-osteoporosis effects.According to the previous research,the extract of Cibotium barumoz,Achyranthes bidentata,Curculigo orchioides,Epimedium brevicornum,Angelica sinensis,Polygonatum sibiricum,Dendrobium officinale,Morinda officinalis,Nelumbo mucifera,Diospyros kaki,Hordeum vulgare,Cistanche deserticola,Commiphora Myrrha and other plant-derived polysaccharides could benefit to the osteoblasts and osteoclasts.The essential mechanisms are mainly related to the activation or inhibition of many factors,including runt-related transcription factor 2(Runx2),B-catenin,osterix(Osx),activator protein-1(AP-1),osteocalcin(OCN/BGP),alkaline phosphatase(ALP),osteopontin(OPN),bone morphogenetic protein(BMP),phosphatidylinositol 3-kinase(PI3K)/C-Jun N-terminal kinase(JNK)/extracellular regulated protein kinase(ERK),osteoprotegerin(OPG),receptor activator of nuclear factor-kB(RANK),monocyte/macrophage colony-stimulating factor(M-CSF),tumor necrosis factor receptor-associated factor 6(TRAF-6),receptor activator of nuclear factor(NF)-KB ligand(RANKL),nuclear factor of activated T cells 1(NFATc1),c-Fos,matrix metallopeptidase-9(MMP-9),glycogen synthase kinase 3β(GSK3B)/B-catenin,nuclear factor E2-related factor 2(Nf2),as well as these related pathways,such as Wnt/p-catenin,BMP-2/SMAD1/5/8,PI3K/AKT,OPG/RANKL/RANK,NF-κB,MAPKs,etc.These plant-derived polysaccharides could improve the dynamic balance of bone formation and resorption through promoting the differentiation and maturation of osteoblast or inhibiting its formation.The reviewed plant-derived polysaccharides and their regulating mechanisms on the osteoclasts and osteoblasts provide the evidences for the development of osteoporosis therapeutics.

The protection of Thymus vulgaris leaves alcoholic extract against hepatotoxicity of alcohol in rats

Objective:This study was performed to investigate the protective effect of Thymus vulgaris(T.vulgaris) leaves 70%alcoholic extract against alcohol-mediate hepatotoxicity rats.Methods:The protective effect of extract was investigated at dose of 500 mg/kg/day orally against alcohol-mediate hepatotoxicity using adult male Wister albino rats during 21 days.Protective effect of T.vulgaris extract was evaluated comparing with silymarin standard drug al recommended dose(25 mg/kg/day) orally for 21 days.Results:Alcohol-mediate hepatotoxicity rats(alcohol-control) showed hepatocytes distortion represented as marked increment on liver biomarkers;alkaline phosphatase(ALP),aspartate transaminase(AST) and alanine transaminase(ALT) activities,as well as pronounced reduction on total protein and its fractions albumin and globulin corresponding to normal ranges.Addition to oxidative stress status as depletion on glutathione concentration,catalase(CAT),superoxide dismutase(SOD),glutathione reductase(GR),glutathione-S-transferase(GST) and glutathione peroxidase(GPx)activities,concurrence with augmentation oxidative stress parameters;malondyaldchydc(MDA) and hydrogen peroxide(H_2O_2) concentrations comparing to normal values.Alcohol administration elevated total cholesterol(TC),low density lipoprotein cholesterol(LDL-C) and high density lipoprotein cholesterol(HDL-C) comparing to normal ranges.Co-administration T.vulgaris extract with alcohol showed protective effect on hepatocytes manifested as minimizing on ALP.AST and ALT activities and increment on total protein,albumin and globulin production compared to alcohol-control.Antioxidant enzymes activities;CAT.SOD.GR,GST and GPx were significantly magnified,while MDA and H_2O_2 concentration were lessened corresponding to alcohol-control.Also,lipid profile was markedly improved and risk ratio was lowered compared to alcohol-control.These results were confirmed by normalization of degenerated and fibrotic liver tissue as of alcohol-control.Conclusion:T.vulgaris extract appeared hepatoprotective,hypolipidemic and antioxidant activities on alcohol-mediate hepatotoxicity rats compared to silymarin.

Hepatoprotection by dandelion (Taraxacum officinale) and mechanisms

The protection of the liver as an essential organ in the body against oxidative stress and deleterious compounds has been the subject of recent investigations.Among different compounds,medicinal plants play an important role due to their hepatoprotective effects.Taraxacum officinale or"common dandelion"is a popular plant that has been traditionally used for its hepatoprotective effects.Currently,there are limited clinical studies on its hepatoprotective effects.The aim of this review article is to evaluate the hepatoprotective effects of dandelion and its mechanism of action.We reviewed literature up to July 2019 on"Taraxacum officinale"or"dandelion"and hepatoprotection.Currently available pharmacological studies indicate that dandelion extracts have hepatoprotective effects against chemical agents due to its antioxidant and antiinflammatory activities.The anti-inflammatory effects of dandelion,the prebiotic effects of its oligofructans,inhibitory effects against the release of lipopolysaccharides and fasting induced adipose factor,digestive enzymes,and enhancing effects of lipogenesis,reduce lipid accumulation and liver inflammation,which directly or indirectly improve the liver functions.Given emerging evidence on hepatoprotective effects of dandelion,designing large human clinical studies is essential.

Melissa officinalis and rosmarinic acid in management of memory functions and Alzheimer disease

Alzheimer disease(AD) as worldwide progressive neurodegenerative disease is prevalent disease among elderly population. Due to limitation in chemical drugs along with their adverse effects of these treatments, research for finding more effective natural drugs, is one of interesting subjects among the scientists. Melissa officinalis(M. officinalis) has a long history of use in treatment of nervous system diseases. This review article evaluates the potency of M. officinalis in treatment of AD by review of experimental and clinical documents on the efficacy, safety and its mechanisms of action in management of AD. The information is extracted from electronic resources(PubMed, Wiley, Springer and Science Direct), English and Persian scientific books. In spite of different scientific and non-scientific reports on the use of M. officinalis and its main component of rosmarinic acid in neurodegenerative diseases, there is only one clinical trial on the efficacy of M. officinalis ethanol extract in management of AD. Different mechanisms of action for M. officinalis, including inhibitory effects against amyloid beta, reactive oxygen species, and acetylcholine esterase, are involved. Larger clinical trials are recommended to confirm the efficacy and safety of M. officinalis extracts in treatment of AD patients.

Comparative analysis of antioxidant activities of essential oils and extracts of fennel(Foeniculum vulgare Mill.)seeds from Egypt and China

The present study was conducted to assay the antioxidant activities of essential oils and ethanol extracts of fennel(Foeniculum vulgare Mill.)seeds from Egypt and China.The major components of the Egyptian fennel essential oil were estragole(51.04%),limonene(11.45%),l-fenchone(8.19%)and trans-anethole(3.62%)by GC–MS analysis.Whereas,the major constituents of Chinese fennel essential oil were transanethole(54.26%),estragole(20.25%),l-fenchone(7.36%)and limonene(2.41%).The fennel seed extracts from Egypt and China contained appreciable levels of total phenolic contents(42.24 and 30.94 mg PE/g,respectively).The extracts exhibited good DPPH radical scavenging capacity with IC50(6.34 and 7.17 mg/g),respectively.A high variation in free radical scavenging activities of essential oils was observed.The Chinese fennel essential oil showed high activity in DPPH radical scavenging with IC50(15.66 mg/g).The Egyptian fennel essential oil showed very low activity with IC50(141.82 mg/g).The results of the present investigation demonstrated significant variations in the antioxidant activities of fennel essential oils and extracts from Egypt and China.

Nanobiotechnology for the Detection and Control of Waterborne Parasites

Nowadays, the fast development of nanobiotechnology, has led to rapid diagnosis of important infectious diseases such as arboviruses-borne diseases, vector-borne infections and waterborne parasites diseases and others in order to reduce and avoid further dissemination of the infections within the general population. Furthermore, new nanomedicines based on the application of silver and gold nanoparticles which are less toxic, more effective, and that does not generate resistance could help to solve the problems of parasitic disease like leishmaniasis and chagas disease. It turns out that the combination of nanoparticles with antibiotics not only reduces the toxicity of both agents towards human cells but also enhances their ability to destroy bacteria by facilitating the binding of antibiotics to the microbes. Moreover, combining nanoparticles with antimicrobial peptides and essential oils with nanoparticles generates genuine synergy against microbial resistance.

Study on the Biology and Epidemiology of Uncinula necator---The Causal Agent of Grape Powdery Mildew Disease

This study was carried out during 2007-2009 in the vineyards of Ardebil province of lran to study the biology and the epidemiology of Uncinula necator--the causal agent of grape powdery mildew disease. The study concentrated on the survival and the initiation of primary inoculum of the fungal causal agent. Results of histopathological experiments indicated that U. necator survived as mycelium in the dormant buds of the grapes during winter season. Results of study on the effect of environmental factors on fungus biology showed that the pathogenic activity of the fungus began when the temperature was between 16-19 ℃ with a relative humidity more than 50%. It was also found that optimum temperature and relative humidity for the sporulation of U.necator was 20-25 ~C and 50%-100% respectively. According to the results, fungal conidia were trapped during formation of 5-6 true leaves and first disease symptoms were observed on the clusters on late June after fruit formation. Fungal cleistothecia were observed abundantly at the end of season on the leaves, petioles and twigs but they were not able to survive during winter. Formation of ascospores on young leaves was proved but their role as the primary inoculum was not supported by the results of this study. Results of this study and the new findings on the biology and epidemiology of U.necator may be of national and international interests for the management of powdery mildew disease which is one of the most destructive diseases around the world including Iran.

Molecular Study of a New Disease of Peach in Iran Associated with a Phytoplasma

In recent years, a disease has been reported to affect peach trees in Kurdistan province of Iran causing serious losses to the production. Main symptoms of disease include leaf stunting and yellowing, which lead to failure in fruit production at harvest. For diagnosis of disease and identification of the causal agent, symptomatic leaf samples were collected in Kurdistan orchards during summer 2010 and were carried to the laboratory. Total DNA was extracted from plant samples according to the standard procedures and indexed by grafting and nested PCR using phytoplasma generic primers, P1/P7 and R16F2n/R2. PCR products were characterized by RFLP technique and direct sequencing. The 16S rDNA sequences were compared with those of other phytoplasmas in GenBank. Phytoplasma rDNA was amplified from 20 out 35 samples. The 16S rDNA sequences of the phytoplasma were identified in Peach samples which showed 98% similarity to that of “Candidatus Phytoplasma phoenicium” which is considered to be the causal agent of Almond witches’ broom. Phylogenetic analysis of 16S rDNA sequences placed peach strains in Almond witches broom isolate as a member of pigeon pea witches broom (PPWB) group. Further studies on the epidemiology of “Ca. Phytoplasma phoenicium” and its vector(s) in Iran are recommended in order to identify new natural hosts and develop successful disease management programs.

Effects of Different Heating Systems on Cucumber Yield in Greenhouses and Cost and Gas Volume Consumed in Varamin Region

This research was conducted to investigate the effects of three heating systems on cucumber yield,and cost and gas volume consumed in greenhouses located in Varamin region,Tehran province,Iran.Conventional heating systems used in the greenhouses are:central heating system(including boiler+hot water pipes),gas heater system(including double-walled tank+blower)and traditional furnace system(including ignition chamber+torch+pipes carrying a mixture of hot air and flammable gases).The study was carried out for two consecutive cucumber cultivation periods from January to June.Average values of crop yield,volume and cost of gas consumed were determined separately for each heating system.Results of the study indicated that the central heating system with the highest crop yield(295 t/ha),and the lowest volume(100,000 m^(3)/ha)and cost(840 USD/ha)of gas consumed was the best and most suitable heating system for greenhouses producing cucumbers in Varamin region and other regions with the same and similar climate as well as regions with active greenhouses in the cold season.

Nanopesticides and Nanofertilizers and Agricultural Development: Scopes, Advances and Applications

Excessive use of pesticides and fertilizers in agriculture in order to increase yields has proved unnecessary because a large part of them remain unused and have negative effects on the environment and human health. Therefore, it is a great challenge for farmers to replace the application of pesticides and fertilizers with nanopesticides and nanofertilizers, with the aim of reducing the use of mineral fertilizers and increasing yields, as well as supporting agricultural development. This review provides a detailed overview of the classification of pesticides, commonly used nanoparticles in agriculture and their function, as well as impact of nanopesticides and nanofertilizers on the environment. The application of nanopesticides and nanofertilizers and new delivery mechanisms to improve crop productivity are reviewed and described. Particularly, the advantage of the nanoencapsulation process is emphasized for both pesticides and fertilizers. For hydrophobic pesticides, it may be a tool to provide greater stability, dispersion in aqueous media, and allowing a controlled release of the active compound, which increases its effectiveness. In nanofertilizers, micro- or macronutrients can be encapsulated by nanomaterials which allow to release of nutrients into the soil gradually and in a controlled way maintaining soil fertility, thus preventing eutrophication and pollution of water resources. Risks assessment of application of nanopesticides and nanofertilizers in agriculture are required for their correct and safe application.

Chemical Composition and Biological Significance of Thymol as Antiparasitic

Thymol is one of the most important phytochemical components because of its pharmacological and bioactive potential effects. This review focuses particularly on thymol as an alternative natural antiparasitic with potential use in the pharmaceutical industry. This is in line with the preferences of the natural products for treatment being safer and without side effects. The biosynthesis pathways of thymol and carvacrol have been discussed, and mechanism of action of thymol on parasites. Studies on thymol confirmed the activity of thymol as anti-parasite against anthelmintic, Trypanosoma ssp., Toxoplasma gondii, Leishmania spp., Plasmodium falciparum, Giardia duodenalis, Eimeria ssp., Cryptosporidium baileyi and Cryptosporidium galli.

Pineapple (<i>Ananas comosus</i>L. Merr.), Waste Streams, Characterisation and Valorisation: An Overview

Processing pineapple industry produces huge amounts of waste thus contributing to worsen the global environmental problem. Valorising pineapple waste through further processing until it is transformed into valuable products using environmentally friendly techniques is both, a challenge, and an opportunity. The aim of this review is to characterize and highlight the phytochemical constituents of pineapple peel, their biological activity, and to evaluate the current state-of-art for the utilization of pineapple waste from the processing industry for obtaining pharmaceuticals, food, and beverages, biocombustibles, biodegradable fibers, and other different usage. Pineapple residues are rich in many bioactive compounds such as ferulic acid, vitamin A and C as antioxidant, and containing alkaloids, flavonoids, saponins, tannins, cardiac glycoside, steroids, triterpenoids and phytosterols may provide a good source of several beneficial properties, as well as bromelain that showed significant anticancer activity. Also, pineapple processing residues contain important volatile compounds used as aroma enhancing products and have high potential to produce value-added natural essences. Pineapple peels can be used as nonpharmacological therapeutical in the form of processed food and instant drinks;its potent natural antimicrobial properties may be applied for food conservation and as potential leads to discover new drugs to control some infectious microbial. Pineapple waste is a promising source of metabolites for therapeutics, functional foods, and cosmeceutical applications.

Genotype×tillage interaction and the performance of winter bread wheat genotypes in temperate and cold dryland conditions

Growing concerns for food security and the alleviation of hunger necessitate knowledge-based crop management technologies for sustainable crop production.In this study,13 winter bread wheat genotypes(old,relatively old,modern,and breeding lines)were evaluated under three different tillage systems,i.e.,conventional tillage(CT,full tillage with residue removed),reduced tillage(RT,chisel tillage with residue retained)and no-tillage(NT,no-tillage with residue retained on the soil surface)in farmer’s fields under rainfed conditions using strip-plot arrangements in a randomized complete block design with three replications in the west of Iran(Kamyaran and Hosseinabad locations)over two cropping seasons(2018–2019 and 2019–2020).The main objectives were to investigate the effects of tillage systems and growing conditions on the agronomic characteristics,grain yield and stability performance of rainfed winter bread wheat genotypes.Significant(P<0.01)genotype×tillage system interaction effects on grain yield and agronomic traits suggested that the genotypes responded differently to the different tillage systems.The number of grains per spike and plant height were positively(P<0.0)associated with grain yield under the NT system,so they may be considered as targeted traits for future wheat breeding.Using statistical models,the modern cultivars(“Sadra”and“Baran”)were identified as high yielding and showed yield stability across the different tillage systems.As per each tillage system,genotype“Sadra”followed by“Zargana-6//Dari 1-7 Sabalan”exhibited higher adaption to CT;while cultivars“Jam”and“Azar2”showed better performance under the RT system;and cultivars“Varan”and“Baran”tended to have better performance expression in the NT condition.The increased grain yields achieved in combination with lower costs and greater profits from conservation agriculture suggest that adapted cultivar and NT systems should be evaluated and promoted more widely to farmers in the west of Iran as an attractive package of crop management technologies.In conclusion,variations in the performance of genotypes and the significant genotype×tillage system interaction effects on grain yield and some agronomic traits assessed in this study suggest that the development and selection of cultivars adapted to the NT system should be considered and included in the strategies and objectives of winter wheat breeding programs for the temperate and cold dryland conditions of Iran.

Dissecting the molecular basis of spike traits by integrating gene regulatory networks and genetic variation in wheat

Spike architecture influences both grain weight and grain number per spike,which are the two major components of grain yield in bread wheat(Triticum aestivum L.).However,the complex wheat genome and the influence of various environmental factors pose challenges in mapping the causal genes that affect spike traits.Here,we systematically identified genes involved in spike trait formation by integrating information on genomic variation and gene regulatory networks controlling young spike development in wheat.We identified 170 loci that are responsible for variations in spike length,spikelet number per spike,and grain number per spike through genome-wide association study and meta-QTL analyses.We constructed gene regulatory networks for young inflorescences at the double ridge stage and thefloret primordium stage,in which the spikelet meristem and thefloret meristem are predominant,respec-tively,by integrating transcriptome,histone modification,chromatin accessibility,eQTL,and protein–pro-tein interactome data.From these networks,we identified 169 hub genes located in 76 of the 170 QTL regions whose polymorphisms are significantly associated with variation in spike traits.The functions of TaZF-B1,VRT-B2,and TaSPL15-A/D in establishment of wheat spike architecture were verified.This study provides valuable molecular resources for understanding spike traits and demonstrates that combining genetic analysis and developmental regulatory networks is a robust approach for dissection of complex traits.

Plant Programmed Cell Death Caused by an Autoactive Form of Prf Is Suppressed by Co-Expression of the Prf LRR Domain

In tomato, the NBARC-LRR resistance （R） protein Prf acts in concert with the Pto or Fen kinase to determine immunity against Pseudomonas syringae pv. tomato （Pst）. Prf-mediated defense signaling is initiated by the recognition of two sequence-unrelated Pst-secreted effector proteins, AvrPto and AvrPtoB, by tomato Pto or Fen. Prf detects these inter- actions and activates signaling leading to host defense responses including localized programmed cell death （PCD） that is associated with the arrest of Pst growth. We found that Prf variants with single amino acid substitutions at D1416 in the IHD motif （isoleucine-histidine-aspartic acid） in the NBARC domain cause effector-independent PCD when transiently expressed in leaves of Nicotiana benthamiana, suggesting D1416 plays an important role in activation of Prf. The N-ter- minal region of Prf （NPrf） and the LRR domain are required for this autoactive Prf cell death signaling but dispensable for accumulation of the PrfD1416V protein. Significantly, co-expression of the Prf LRR but not NPrf, with PrfD1416v, AvrPto/Pto, AvrPtoB/Pto, an autoactive form of Pro （PtoY207D）, or Fen completely suppresses PCD. However, the Prf LRR does not in- terfere with PCD caused by Rpi-blblD475v a distinct R protein-mediated PCD signaling event, or that caused by overex- pression of MAPKKKα, a protein acting downstream of Prf. Furthermore, we found the PrfD1416V protein is unable to accumulate in plant cells when co-expressed with the Prf LRR domain, likely explaining the cell death suppression. The mechanism for the LRR-induced degradation of PrfD1416V is unknown but may involve interference in the intramo- lecular interactions of Prf or to binding of the unattached LRR to other host proteins that are needed for Prf stability.