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1.
Plant J ; 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34647389

RESUMO

Mycoheterotrophic and parasitic plants are heterotrophic and respectively parasitize on fungi and plants to obtain nutrients. Large-scale comparative genomics has not been conducted among mycoheterotrophic or parasitic plants or between these two groups of parasites. We assembled a chromosome-level genome of the fully mycoheterotrophic plant Gastrodia elata (Orchidaceae) and performed comparative genomic analyses on the genomes of G. elata and four orchids (initial mycoheterotrophs), three parasitic plants Cuscuta australis, Striga asiatica, and Sapria himalayana, and 36 autotrophs plants from various angiosperm lineages. It was found that while in the hemiparasite Striga asiatica and initial mycoheterotrophic orchids, ~4-5% of the conserved orthogroups were lost, the fully heterotrophic G. elata and C. australis both lost ~10% of the conserved orthogroups, indicating that increased heterotrophy level is positively associated with gene loss. Importantly, many genes essential for autotrophs, including those involved in photosynthesis, circadian clock, flowering time regulation, immunity, nutrient uptake, and root and leaf development, were convergently lost in both G. elata and C. australis. The high-quality genome of G. elata will facilitate future studies on the physiology, ecology, and evolution of mycoheterotrophic plants, and our findings highlight the critical role of gene loss in the evolution of plants with heterotrophic lifestyles.

2.
BMJ Open ; 11(8): e043883, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376438

RESUMO

OBJECTIVE: The transmuscular quadratus lumborum (TQL) block and the oblique subcostal transversus abdominis plane (OSTAP) block both contribute to multimodal analgesia after laparoscopic surgery. The objective of this study was to compare the analgesic effects of the TQL block versus OSTAP block after laparoscopic hysterectomy. DESIGN: Prospective single-centre randomised single-blind trial. SETTING: University-affiliated hospital. PARTICIPANTS: Patients aged between 18 and 65 years scheduled for laparoscopic hysterectomy. INTERVENTIONS: Patients were randomised into two groups (1:1 ratio) and received bilateral TQL block or bilateral OSTAP block with 0.375% ropivacaine 20 mL on each side before surgery. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measure was the cumulative morphine dose in the first 24 hours. The secondary outcome measures were the morphine consumption at each time interval after surgery, the time from the end of surgery to the first need for morphine, the Numerical Rating Scale (NRS) scores for visceral and incisional pain intensity, and the incidence of adverse events. RESULTS: The cumulative morphine dose was significantly lower in the TQL group than in the OSTAP group (17.2 (12.5) vs 26.1 (13.3) mg, p=0.010). Compared with the OSTAP group, the morphine doses from 6 to 12, 12 to 18, and 18 to 24 hours were significantly lower, the time of first need for morphine was significantly longer and the NRS scores for visceral pain intensity were significantly lower in the TQL group. CONCLUSION: Compared with the OSTAP block, the TQL block reduced morphine consumption and provided better visceral pain relief with a longer duration of effect after laparoscopic hysterectomy. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry (ChiCTR1800017995); pre-results.


Assuntos
Analgesia , Laparoscopia , Músculos Abdominais , Adolescente , Adulto , Idoso , Analgésicos Opioides , Anestésicos Locais , Método Duplo-Cego , Feminino , Humanos , Histerectomia , Pessoa de Meia-Idade , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle , Estudos Prospectivos , Método Simples-Cego , Adulto Jovem
3.
Int J Dev Neurosci ; 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34198359

RESUMO

Anaesthesia exposure causes changes in the developing brain and affects behaviour and memory. This study examined the beneficial effect of pachypodol against isoflurane (ISF)-induced neuronal injury. Seven-day-old rats were treated with 10 mg/kg and 30 mg/kg intravenous pachypodol 30 min before exposure to ISF (0.75%) for 6 h. Oxidative stress and other biochemical parameters were assessed in the brain tissue and serum using enzyme-linked immunosorbent assay. Additionally, a terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay was performed to assess neuronal cell apoptosis in several regions of the hippocampus. Cognitive function and neurological scores were determined in the pachypodol-treated neuron-injured rats. Cytokine levels and oxidative stress were reduced in the pachypodol-treated group compared with the ISF group. In addition, cognitive deterioration was reversed in pachypodol-treated compared with ISF-treated rats. Thus, treatment with pachypodol reduced neuronal apoptosis in neuron-injured rats. Moreover, pachypodol ameliorated changes to the JNK/ERK/Akt pathway in brain-injured rats. In conclusion, pachypodol treatment prevents neuronal apoptosis in ISF-treated rats by regulating the JNK/ERK pathway.

4.
J Exp Bot ; 2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34293107

RESUMO

Herbivory-induced systemic signaling has been demonstrated in monocots and dicots and is essential for plant defense against insects. However, the nature and evolution of herbivory-induced systemic signals remain unclear. Grafting is widely used for studying systemic signaling; however, grafting between dicot plants from different families is difficult and grafting is impossible for monocots. In this study, taking advantage of dodder's extraordinary capability of parasitizing various plant species, the field dodder (Cuscuta campestris) was employed to pairwise connect phylogenetically very distant plants, ranging from fern to monocot and dicot plants, and whether interplant signaling occurs after simulated herbivory was analyzed. It was found that simulated herbivory-induced systemic signals can be transferred by dodder between a monocot and a dicot plant and even between a fern and a dicot plant, and the plants that received the systemic signals all exhibited elevated defenses. Thus, we inferred that the herbivory-induced systemic signals are likely evolutionally well conserved among vascular plants. Importantly, we also demonstrate that the jasmonate pathway is likely an ancient regulator of the biosynthesis and/or transport of systemic signals in vascular plants. These findings provide new insight into the nature and evolution of systemic signaling.

5.
Plant Physiol ; 185(4): 1395-1410, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33793912

RESUMO

Dodder (Cuscuta spp., Convolvulaceae) is a genus of parasitic plants with worldwide distribution. Dodders are able to simultaneously parasitize two or more adjacent hosts, forming dodder-connected plant clusters. Nitrogen (N) deficiency is a common challenge to plants. To date, it has been unclear whether dodder transfers N-systemic signals between hosts grown in N-heterogeneous soil. Transcriptome and methylome analyses were carried out to investigate whether dodder (Cuscuta campestris) transfers N-systemic signals between N-replete and N-depleted cucumber (Cucumis sativus) hosts, and it was found that N-systemic signals from the N-deficient cucumber plants were rapidly translocated through C. campestris to the N-replete cucumber plants. Unexpectedly, certain systemic signals were also transferred from the N-replete to N-depleted cucumber hosts. We demonstrate that these systemic signals are able to regulate large transcriptome and DNA methylome changes in the recipient hosts. Importantly, N stress also induced many long-distance mobile mRNA transfers between C. campestris and hosts, and the bilateral N-systemic signaling between N-replete and N-depleted hosts had a strong impact on the inter-plant mobile mRNAs. Our 15N labeling experiment indicated that under N-heterogeneous conditions, N-systemic signals from the N-deficient cucumber hosts did not obviously change the N-uptake activity of the N-replete cucumber hosts; however, in plant clusters comprising C. campestris-connected cucumber and soybean (Glycine max) plants, if the soybean plants were N-starved, the cucumber plants exhibited increased N-uptake activity. This study reveals that C. campestris facilitates plant-plant communications under N-stress conditions by enabling extensive bilateral N-systemic signaling between different hosts.


Assuntos
Cuscuta/genética , Cuscuta/fisiologia , Cuscuta/parasitologia , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/fisiologia , Proteínas PII Reguladoras de Nitrogênio/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas PII Reguladoras de Nitrogênio/genética
6.
Proc Natl Acad Sci U S A ; 117(37): 23125-23130, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32868415

RESUMO

Many plants use environmental cues, including seasonal changes of day length (photoperiod), to control their flowering time. Under inductive conditions, FLOWERING LOCUS T (FT) protein is synthesized in leaves, and FT protein is a mobile signal, which is able to travel to the shoot apex to induce flowering. Dodders (Cuscuta, Convolvulaceae) are root- and leafless plants that parasitize a large number of autotrophic plant species with varying flowering time. Remarkably, some dodder species, e.g., Cuscuta australis, are able to synchronize their flowering with the flowering of their hosts. Detailed sequence inspection and expression analysis indicated that the FT gene in dodder C. australis very likely does not function in activating flowering. Using soybean host plants cultivated under inductive and noninductive photoperiod conditions and soybean and tobacco host plants, in which FT was overexpressed and knocked out, respectively, we show that FT-induced flowering of the host is likely required for both host and parasite flowering. Biochemical analysis revealed that host-synthesized FT signals are able to move into dodder stems, where they physically interact with a dodder FD transcription factor to activate dodder flowering. This study demonstrates that FTs can function as an important interplant flowering signal in host-dodder interactions. The unique means of flowering regulation of dodder illustrates how regressive evolution, commonly found in parasites, may facilitate the physiological synchronization of parasite and host, here allowing the C. australis parasite to time reproduction exactly with that of their hosts, likely optimizing parasite fitness.


Assuntos
Cuscuta/fisiologia , Cuscuta/parasitologia , Flores/fisiologia , Flores/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Parasitos/fisiologia , Animais , Regulação da Expressão Gênica de Plantas/fisiologia , Folhas de Planta/parasitologia , Folhas de Planta/fisiologia , Soja/parasitologia , Soja/fisiologia , Tabaco/parasitologia , Tabaco/fisiologia , Fatores de Transcrição/metabolismo
7.
BMC Anesthesiol ; 20(1): 88, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32312233

RESUMO

BACKGROUND: Ultrasound-guided erector spine plane (ESP) block is widely used in perioperative analgesia for back, chest and abdominal surgery. The extent and distribution of this block remain controversial. This study was performed to assess the analgesia range of an ultrasound-guided ESP block. METHODS: This prospective observational volunteer study consisted of 12 healthy volunteers. All volunteers received an erector spinae plane block at the left T5 transverse process using real-time ultrasound guidance. Measured the cutaneous sensory loss area (CSLA) and cutaneous sensory declination area (CSDA) using cold stimulation at different time points after blockade until its disappearance. The CSLA and CSDA were mapped and then calculated. The block range was described by spinous process level and lateral extension. The effective block duration for each volunteer was determined and recorded. RESULTS: The cold sensory loss concentrates at T6-T9. The decline concentrates primarily at T4-T11. The lateral diffusion of block to the left side did not cross the posterior axillary line, and reached the posterior median line on the right. The area of cutaneous sensory loss was (172 ± 57) cm2, and the area of cutaneous sensory decline was (414 ± 143) cm2. The duration of cutaneous sensory decline was (586 ± 28) minutes. CONCLUSION: Ultrasound-guided erector spine plane block with 20 mL of 0. 5% ropivacaine provided a widespread cutaneous sensory block in the posterior thorax, but did not reach the anterior chest, lateral chest, or abdominal walls. The range of the blockade suggested that the dorsal branch of spinal nerve was blocked. TRIAL REGISTRATION: Chinese Clinical Trial Registry, CHiCTR1800014438. Registered 13 January 2018.


Assuntos
Anestésicos Locais/administração & dosagem , Bloqueio Nervoso/métodos , Dor/prevenção & controle , Ropivacaina/administração & dosagem , Adulto , Anestésicos Locais/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculos Paraespinais/diagnóstico por imagem , Estudos Prospectivos , Ropivacaina/farmacologia , Tórax , Ultrassonografia de Intervenção
8.
Mol Plant ; 13(4): 573-585, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-31812691

RESUMO

Cuscuta species (dodders) are holoparasites that totally rely on host plants to survive. Although various mobile proteins have been identified to travel within a plant, whether and to what extent protein transfer between Cuscuta and host plants remain unclear. We found that hundreds to more than 1500 proteins were transferred between Cuscuta and the host plants Arabidopsis and soybean, and hundreds of inter-plant mobile proteins were even detected in the seeds of Cuscuta and the host soybean. Different hosts bridge-connected by dodder were also found to exchange hundreds of proteins. Quantitatively, the mobile proteins represent a few to more than 10% of the proteomes of foreign plants. Using Arabidopsis plants expressing different reporter proteins, we further showed that these reporter proteins could travel between plants and, importantly, retained their activity in the foreign plants. Comparative analysis between the inter-plant mobile proteins and mRNAs indicated that the majority of mobile proteins were not de novo synthesized from the translocated mRNAs, but bona fide mobile proteins. We propose that large-scale inter-plant protein translocation may play an important role in the interactions between host plants and dodder and even among the dodder bridge-connected hosts.


Assuntos
Arabidopsis/parasitologia , Cuscuta/fisiologia , Proteínas de Plantas/metabolismo , Soja/parasitologia , Arabidopsis/metabolismo , Cuscuta/metabolismo , Interações Hospedeiro-Parasita , Plantas Geneticamente Modificadas , Transporte Proteico , Proteômica , RNA Mensageiro/metabolismo , Sementes/metabolismo , Soja/metabolismo
9.
J Exp Bot ; 71(3): 1171-1184, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31665509

RESUMO

The dodders (Cuscuta spp.) are a genus of shoot parasites. In nature, a dodder often simultaneously parasitizes two or more neighboring hosts. Salt stress is a common abiotic stress for plants. It is unclear whether dodder transmits physiologically relevant salt stress-induced systemic signals among its hosts and whether these systemic signals affect the hosts' tolerance to salt stress. Here, we simultaneously parasitized two or more cucumber plants with dodder. We found that salt treatment of one host highly primed the connected host, which showed strong decreases in the extent of leaf withering and cell death in response to subsequent salt stress. Transcriptomic analysis indicated that 24 h after salt treatment of one cucumber, the transcriptome of the other dodder-connected cucumber largely resembled that of the salt-treated one, indicating that inter-plant systemic signals primed these dodder-connected cucumbers at least partly through transcriptomic reconfiguration. Furthermore, salt treatment of one of the cucumbers induced physiological changes, including altered proline contents, stomatal conductance, and photosynthetic rates, in both of the dodder-connected cucumbers. This study reveals a role of dodder in mediating salt-induced inter-plant signaling among dodder-connected hosts and highlights the physiological function of these mobile signals in plant-plant interactions under salt stress.


Assuntos
Cuscuta/metabolismo , Tolerância ao Sal , Ecossistema , Interações Hospedeiro-Parasita , Transcriptoma
10.
BMC Plant Biol ; 19(1): 540, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31801469

RESUMO

BACKGROUND: Dodder (Cuscuta spp., Convolvulaceae) species are obligate leaf- and rootless parasites that totally depend on hosts to survive. Dodders naturally graft themselves to host stems to form vascular fusion, from which they obtain nutrients and water. In addition, dodders and their hosts also exchange various other molecules, including proteins, mRNAs, and small RNAs. It is very likely that vascular fusion also allows inter-plant translocation of systemic signals between dodders and host plants and these systemic signals may have profound impacts on the physiology of dodder and host plants. Herbivory is a common biotic stress for plants. When a dodder parasite is attacked by lepidopteran insects, how dodder responds to caterpillar feeding and whether there are inter-plant communications between the host plants and the parasites is still poorly understood. RESULTS: Here, wild-type (WT) tobacco and a tobacco line in which jasmonic acid (JA) biosynthesis was silenced (AOC-RNAi) were used as the hosts, and the responses of dodders and their host plants to herbivory by Spodoptera litura caterpillars on the dodders were investigated. It was found that after caterpillar attack, dodders grown on AOC-RNAi tobacco showed much a smaller number of differentially expressed genes, although the genotypes of the tobacco plants did not have an effect on the simulated S. litura feeding-induced JA accumulation in dodders. We further show that S. litura herbivory on dodder also led to large changes in transcriptome and defensive metabolites in the host tobacco, leading to enhanced resistance to S. litura, and the JA pathway of tobacco host is critical for these systemic responses. CONCLUSIONS: Our findings indicate that during caterpillar attack on dodder, the JA pathway of host plant is required for the proper transcriptomic responses of both dodder and host plants. This study highlights the importance of the host JA pathway in regulating the inter-plant systemic signaling between dodder and hosts.


Assuntos
Cuscuta/fisiologia , Ciclopentanos/metabolismo , Herbivoria , Oxilipinas/metabolismo , Spodoptera/fisiologia , Tabaco/parasitologia , Transcriptoma , Animais , Cuscuta/genética , Folhas de Planta/fisiologia , Transdução de Sinais , Tabaco/genética
11.
Minerva Anestesiol ; 85(12): 1273-1280, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31486620

RESUMO

BACKGROUND: The efficacy of an ultrasound guided transmuscular quadratus lumborum block (QLB) for perioperative analgesia of the upper and lower abdomen remain debatable. The purpose of this study was to compare the cutaneous sensory blocked area (CSBA) between QLB blocks performed at the L2 vs. L4 levels. METHODS: Twenty-two healthy volunteers were randomized 1:1 to receive an ultrasound guided right transmuscular QLB at the L2 level (group QL2) or L4 level (group QL4). A cold stimulus was applied for testing of the CSBA at 30 minutes after the blockade was performed. The CSBA was mapped and then calculated. Three hours after the QLB, a cold stimulus was applied once every hour until sensation returned normal and the effective block duration for each volunteer was determined and recorded. RESULTS: The maximum cephalad dermatome level reached was T7 in group QL2 vs. T11 in group QL4, respectively. Caudally, both groups reached the L2 dermatome level. The QL2 block primarily affected dermatomes T9 to L1, while the QL4 block affected T11 to L1. The total CSBA was larger in QL2 group than that in QL4 group (748 [171] cm2 vs. 501 [186] cm2, P=0.004). The effective duration of the QLB was significantly longer in group QL2 than in group QL4 (18.5 [2.0]h vs. 14.1 [4.7]h, P=0.012). The number of affected dermatomes assessed by cold test was significantly larger for the volunteers in groups QL2 (4.6 [0.81] vs. 2.1 [0.30], P<0.001). CONCLUSIONS: Ultrasound guided transmuscular QLB injection of 0.375% 20 mL ropivacaine at the L2 level produced a widespread cutaneous sensory blockade and a prolonged sensory block to cold sensation compared with the L4 level.


Assuntos
Bloqueio Nervoso/métodos , Abdome , Músculos Abdominais/inervação , Adulto , Analgesia/métodos , Feminino , Humanos , Região Lombossacral , Masculino , Pessoa de Meia-Idade , Sensação , Fenômenos Fisiológicos da Pele , Fatores de Tempo
12.
Biomed Pharmacother ; 118: 109198, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31336342

RESUMO

ω-3 fish oil fat emulsions contain a considerable quantity of unsaturated carbon-carbon double bonds, which undergo lipid peroxidation to yield low-dose aldehydes. These aldehydes may stimulate the production of antioxidant enzymes, thereby mitigating myocardial oxidative damage. This study aims to (1) verify the cardioprotective effect of ω-3 fish oil fat emulsion in vivo and in vitro, and (2) determine whether aldehyde stress is a protective mechanism. For modeling purposes, we pretreated rats with 2 ml/kg of a 10% ω-3 fish oil fat emulsion for 5 days in order to generate a sufficient aldehyde stress response to trigger the production of antioxidant enzymes, and we obtained similar response with H9C2 cells that were pretreated with a 0.5% ω-3 fish oil fat emulsion for 24 h. ω-3 fish oil fat emulsion pretreatment in vivo reduced the myocardial infarct size, decreased the incidence of arrhythmias, and promoted the recovery of cardiac function after myocardial ischemia/reperfusion injury. Once the expression of nuclear factor E2-related factor 2 (Nrf2) was silenced in H9C2 cells, aldehydes no longer produced enough antioxidant enzymes to reverse the oxidative damage caused by tert-butyl hydroperoxide (TBHP). Our results demonstrated that ω-3 fish oil fat emulsion enhanced the inhibition of oxidation and production of free radicals, and alleviated myocardial oxidative injury via activation of the Nrf2 signaling pathway.


Assuntos
Aldeídos/metabolismo , Ácidos Graxos Ômega-3/farmacologia , Óleos de Peixe/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Antioxidantes/metabolismo , Linhagem Celular , Ácidos Graxos Ômega-3/administração & dosagem , Óleos de Peixe/administração & dosagem , Fator de Transcrição de Proteínas de Ligação GA/metabolismo , Masculino , Mioblastos Cardíacos/efeitos dos fármacos , Mioblastos Cardíacos/metabolismo , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Ratos Sprague-Dawley
13.
Philos Trans R Soc Lond B Biol Sci ; 374(1767): 20180307, 2019 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-30967023

RESUMO

Maize ( Zea mays) is a staple cereal crop cultivated all over the world but that is threatened by various insects. Feeding of the lepidopteran insect Mythimna separata triggers defence signalling and increases anti-herbivore benzoxazinoids (Bxs) in the insect-damaged maize leaves. However, the herbivory-elicited within-leaf and leaf-to-leaf systemic signalling in maize remains largely unexplored. Here, we show that simulated M. separata herbivory and mechanical wounding elicited increased levels of jasmonic acid (JA), JA-Ile (JA-isoleucine conjugate) and Bxs in the damaged areas and in specific systemic regions within a leaf. Importantly, increased contents of Bxs were detected in a systemic leaf, and consistently, this leaf exhibited increased defence against M. separata. Increased JA/JA-Ile and altered transcriptome, including Bx biosynthesis genes, were detected in systemic leaves after wounding or simulated herbivory treatments, although only simulated herbivory induced increase of the contents of Bxs systemically. Promoter and co-expression analysis revealed that transcription factors bHLH57 and WRKY34 may regulate Bx biosynthesis genes in systemic leaves. Moreover, leaf ablation experiment indicated that the systemic signal rapidly exited the local leaves within 30 min after elicitation. This study provides new insight into the temporal and spatial regulation of defence responses of maize against lepidopteran insects. This article is part of the theme issue 'Biotic signalling sheds light on smart pest management'.


Assuntos
Antibiose , Herbivoria , Mariposas/fisiologia , Transdução de Sinais , Zea mays/fisiologia , Animais , Ciclopentanos/farmacologia , Comportamento Alimentar , Isoleucina/farmacologia , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Oxilipinas/farmacologia , Folhas de Planta/fisiologia
14.
Nat Commun ; 9(1): 2683, 2018 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-29992948

RESUMO

Dodders (Cuscuta spp., Convolvulaceae) are root- and leafless parasitic plants. The physiology, ecology, and evolution of these obligate parasites are poorly understood. A high-quality reference genome of Cuscuta australis was assembled. Our analyses reveal that Cuscuta experienced accelerated molecular evolution, and Cuscuta and the convolvulaceous morning glory (Ipomoea) shared a common whole-genome triplication event before their divergence. C. australis genome harbors 19,671 protein-coding genes, and importantly, 11.7% of the conserved orthologs in autotrophic plants are lost in C. australis. Many of these gene loss events likely result from its parasitic lifestyle and the massive changes of its body plan. Moreover, comparison of the gene expression patterns in Cuscuta prehaustoria/haustoria and various tissues of closely related autotrophic plants suggests that Cuscuta haustorium formation requires mostly genes normally involved in root development. The C. australis genome provides important resources for studying the evolution of parasitism, regressive evolution, and evo-devo in plant parasites.


Assuntos
Cuscuta/genética , Evolução Molecular , Deleção de Genes , Genes de Plantas/genética , Genoma de Planta/genética , Cuscuta/classificação , Cuscuta/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Filogenia , Proteínas de Plantas/genética
15.
J Integr Plant Biol ; 60(5): 412-431, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29319235

RESUMO

Atmospheric CO2 levels are rapidly increasing due to human activities. However, the effects of elevated CO2 (ECO2 ) on plant defense against insects and the underlying mechanisms remain poorly understood. Here we show that ECO2 increased the photosynthetic rates and the biomass of tobacco and rice plants, and the chewing lepidopteran insects Spodoptera litura and Mythimna separata gained less and more mass on tobacco and rice plants, respectively. Consistently, under ECO2 , the levels of jasmonic acid (JA), the main phytohormone controlling plant defense against these lepidopteran insects, as well as the main defense-related metabolites, were increased and decreased in insect-damaged tobacco and rice plants. Importantly, bioassays and quantification of defense-related metabolites in tobacco and rice silenced in JA biosynthesis and perception indicate that ECO2 changes plant resistance mainly by affecting the JA pathway. We further demonstrate that the defensive metabolites, but not total N or protein, are the main factors contributing to the altered defense levels under ECO2 . This study illustrates that ECO2 changes the interplay between plants and insects, and we propose that crops should be studied for their resistance to the major pests under ECO2 to predict the impact of ECO2 on future agroecosystems.


Assuntos
Dióxido de Carbono/farmacologia , Ciclopentanos/metabolismo , Oryza/parasitologia , Oxilipinas/metabolismo , Transdução de Sinais , Spodoptera/fisiologia , Tabaco/parasitologia , Animais , Bioensaio , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Nitrogênio/metabolismo , Oryza/efeitos dos fármacos , Oryza/genética , Fotossíntese/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Metabolismo Secundário/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Spodoptera/efeitos dos fármacos , Tabaco/efeitos dos fármacos , Tabaco/genética
16.
Plant Divers ; 40(4): 189-195, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30740564

RESUMO

Plants have sophisticated defense systems to fend off insect herbivores. How plants defend against herbivores in dicotyledonous plants, such as Arabidopsis and tobacco, have been relatively well studied, yet little is known about the defense responses in monocotyledons. Here, we review the current understanding of rice (Oryza sativa) and maize (Zea mays) defense against insects. In rice and maize, elicitors derived from insect herbivore oral secretions or oviposition fluids activate phytohormone signaling, and transcriptomic changes mediated mainly by transcription factors lead to accumulation of defense-related secondary metabolites. Direct defenses, such as trypsin protein inhibitors in rice and benzoxazinoids in maize, have anti-digestive or toxic effects on insect herbivores. Herbivory-induced plant volatiles, such as terpenes, are indirect defenses, which attract the natural enemies of herbivores. R gene-mediated defenses against herbivores are also discussed.

17.
Proc Natl Acad Sci U S A ; 114(32): E6703-E6709, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28739895

RESUMO

Cuscuta spp. (i.e., dodders) are stem parasites that naturally graft to their host plants to extract water and nutrients; multiple adjacent hosts are often parasitized by one or more Cuscuta plants simultaneously, forming connected plant clusters. Metabolites, proteins, and mRNAs are known to be transferred from hosts to Cuscuta, and Cuscuta bridges even facilitate host-to-host virus movement. Whether Cuscuta bridges transmit ecologically meaningful signals remains unknown. Here we show that, when host plants are connected by Cuscuta bridges, systemic herbivory signals are transmitted from attacked plants to unattacked plants, as revealed by the large transcriptomic changes in the attacked local leaves, undamaged systemic leaves of the attacked plants, and leaves of unattacked but connected hosts. The interplant signaling is largely dependent on the jasmonic acid pathway of the damaged local plants, and can be found among conspecific or heterospecific hosts of different families. Importantly, herbivore attack of one host plant elevates defensive metabolites in the other systemic Cuscuta bridge-connected hosts, resulting in enhanced resistance against insects even in several consecutively Cuscuta-connected host plants over long distances (> 100 cm). By facilitating plant-to-plant signaling, Cuscuta provides an information-based means of countering the resource-based fitness costs to their hosts.


Assuntos
Cuscuta/fisiologia , Folhas de Planta/fisiologia , Transdução de Sinais/fisiologia , Animais , Herbivoria/fisiologia , Insetos/fisiologia
18.
Sensors (Basel) ; 15(4): 7136-55, 2015 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-25811226

RESUMO

Compressive sampling or compressed sensing (CS) works on the assumption of the sparsity or compressibility of the underlying signal, relies on the trans-informational capability of the measurement matrix employed and the resultant measurements, operates with optimization-based algorithms for signal reconstruction and is thus able to complete data compression, while acquiring data, leading to sub-Nyquist sampling strategies that promote efficiency in data acquisition, while ensuring certain accuracy criteria. Information theory provides a framework complementary to classic CS theory for analyzing information mechanisms and for determining the necessary number of measurements in a CS environment, such as CS-radar, a radar sensor conceptualized or designed with CS principles and techniques. Despite increasing awareness of information-theoretic perspectives on CS-radar, reported research has been rare. This paper seeks to bridge the gap in the interdisciplinary area of CS, radar and information theory by analyzing information flows in CS-radar from sparse scenes to measurements and determining sub-Nyquist sampling rates necessary for scene reconstruction within certain distortion thresholds, given differing scene sparsity and average per-sample signal-to-noise ratios (SNRs). Simulated studies were performed to complement and validate the information-theoretic analysis. The combined strategy proposed in this paper is valuable for information-theoretic orientated CS-radar system analysis and performance evaluation.

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