Insight into strigolactone hormone functions in plant parasitic weeds: a regulatory perspective

The strigolactones (SLs) are plants hormones that have multiple functions in architecture and development. The roles of SLs in shoot branching and stem secondary growth of autotrophic plants are established. SL is also involved in the interaction between root parasitic plants and their host plants. SLs are exudates by the root of the host plant in search of a fungal partner for symbiotic association, while parasitic plants utilize this facility to detect the host root. The first formed tubercle of Philapanhche, whose germinations are driven by host-derived SLs, exudates parasitic derived SLs (PSLs) and could encourages germination of the adjacent parasitic seeds, resulting in parasite cluster formation. The existence of aboveground spikes in clusters suggests an intriguing approach for increasing parasite population by amplifying PSLs, which result in massive parasitic seed germination. PSLs probably have a role in the increased branching of Broomrapes opposing the host plant, resulting in the parasites' clustered appearance aboveground. This review highlights the distinct roles of SLs and PSLs, and their potential role in host-parasitic interaction.

Effects of Indole-3-Butyric Acid (IBA) and rooting media on rooting and survival of air layered wax apple (Syzygium samarangense) CV Jambu Madu / Efeitos do Ácido Indol-3-Butírico (AIB) e meio de enraizamento no enraizamento e sobrevivência de maçã de cera em camada de ar (Syzygium samarangense) CV Jambu Madu

The wax apple or jambu madu, is a non-climacteric tropical fruit from Myrtaceae family and widely cultivated in South East Asia. The limited availability of good quality seedlings of wax apple is the main problem to development of flourish it's market share in the current fruit industry. Therefore, in order to produce good quality planting materials, a study aimed at optimizing propagation and adventitious rooting technique and survivability of wax apple air layer was conducted. In this study, four different levels of Indole-3-Butyric Acid (IBA) concentration (0, 1000, 1500 and 2000 mg L-1) and three rooting media (sphagnum moss, vermicompost and garden soil) were applied after removal of bark (phloem) on the shoot to determine the effect on rooting and survivability of the wax apple air layer under field conditions. The results showed that the wax apple shoots treated with 2000 mg L-1 IBA produced the significantly higher number of roots, increased length of root, diameter of branch, length of branch, number of leaf and leaf area of air layers. In addition, the highest chlorophyll content and stomatal aperture were recorded in 2000 mg L-1 IBA treatment compared to other treatments including control. Vermicompost medium was better than garden soil and sphagnum moss in respect of rooting and survivability of air layers. The results showed that the combination of 2000 mg L-1 IBA and vermicompost as rooting media give the best combination to root initiation, root number, root length and survival rate (100%) of wax apple air layers. From this study, it can be concluded that 2000 mg L-1 IBA and vermicompost treatment enhance the root initiation, early establishment and survivability of wax apple air layered under field conditions.

A maçã de cera, ou jambu madu, é uma fruta tropical não climatérica da família Myrtaceae e amplamente cultivada no Sudeste Asiático. A disponibilidade limitada de mudas de macieira de boa qualidade é o principal problema para o desenvolvimento de sua participação de mercado na fruticultura atual. Portanto, com o objetivo de produzir materiais de plantio de boa qualidade, foi realizado um estudo visando otimizar a técnica de propagação e enraizamento adventício e a sobrevivência da camada aérea da cera de macieira. Neste estudo, quatro diferentes níveis de concentração de ácido indol-3-butírico (AIB) (0, 1000, 1500 e 2000 mg L-1) e três meios de enraizamento (musgo esfagno, vermicomposto e solo de jardim) foram aplicados após a remoção da casca (floema) na parte aérea para determinar o efeito no enraizamento e capacidade de sobrevivência da camada de ar da macieira em condições de campo. Os resultados mostraram que os brotos de macieira tratados com 2000 mg L-1 de AIB produziram significativamente maior número de raízes, maior comprimento de raiz, diâmetro de galho, comprimento de galho, número de folhas e área foliar das camadas aéreas. Além disso, o maior teor de clorofila e abertura estomática foram registrados no tratamento 2000 mg L-1 IBA em comparação com outros tratamentos, incluindo o controle. O meio de vermicomposto foi melhor do que o solo de jardim e o musgo esfagno em relação ao enraizamento e capacidade de sobrevivência das camadas aéreas. Os resultados mostraram que a combinação de 2000 mg L-1 de AIB e vermicomposto como meio de enraizamento proporciona a melhor combinação para iniciação radicular, número de raízes, comprimento radicular e taxa de sobrevivência (100%) das camadas aéreas de macieira. A partir deste estudo, pode-se concluir que 2.000 mg L-1 de AIB e tratamento com vermicomposto melhoram a iniciação radicular, o estabelecimento precoce e a capacidade de sobrevivência de macieiras em camadas de ar em condições de campo.

Genome-wide identification and transcriptional profiling analysis of PIN/PILS auxin transporter gene families in Panax ginseng / 中草药·英文版

Objective: Plant hormones act as chemical messengers in the regulation of plant development and metabolism. The production of ginsenosides in Panax hybrid is promoted by auxins that are transported and accumulated by PIN-FORMED (PIN) and PIN-LIKES (PILS) auxin transporters. However, genome-wide studies of PIN/PILS of ginseng are still scarce. In current study, identification and transcriptional profiling of PIN/PILS gene families, as well as their potential relationship with ginsenoside biosynthesis in Panax ginseng were investigated. Methods: PIN/PILS genes in P. ginseng was identified via in silico genome-wide analysis, followed by phylogenetic relationships, gene structure, and protein profiles investigation. Moreover, previously reported RNA-sequence data from various tissues and roots after infection were utilized for PIN/PILS genes expression pattern analysis. The Pearson's correlation analysis of specific PIN/PILS genes expression level and main ginsenoside contents were taken to reveal the potential relationship between auxin transports and ginsenoside biosynthesis in P. ginseng. Results: A genome-wide search of P. ginseng genome for homologous auxin transporter genes identified a total of 17 PIN and 11 PILS genes. Sequence alignment, putative motif organization, and sub-cellular localization indicated redundant and complementary biological functions of these PIN/PILS genes. Most PIN/PILS genes were differentially expressed in a tissue-specific manner, and showed significant correlations with ginsenoside content correspondingly. Eight auxin transporter genes, including both PIN and PILS subfamily members, were positively correlated with ginsenoside content (cor > 0.60; P-value <0.05). The expression levels of eleven auxin transporter genes were increased dramatically in the early stage (0–0.5 DPI) after Cylindrocarpon destructans infection, accompanied with various overall expression patterns, implying the dynamic auxin transport in response to biotic stress. Conclusion: Based on the results, we speculate that the accumulation or depletion in temporal or spatial manner of auxin by PIN/PILS transporters involved in the regulation of HMGR activity and subsequent ginsenoside biosynthesis.

In vitro multiplication of wild Manihot species with different naphthaleneacetic acid and benzylaminopurine concentrations

In vitro multiplication is an important tissue culture technique that is capable of efficiently producing seedlings at any scale. It is a propagation method based on the aseptic culture of small propagules in a suitable culture medium to enable plant regeneration. Multiplication experiments conducted in vitro to set protocols adapted to wild Manihot species have used modified mineral salts and MS vitamins as basic culture medium. Here, 25 treatments based on combinations of the regulators benzylaminopurine (BAP) and naphthaleneacetic acid (NAA) at 0, 0.025, 0.05, 0.075, and 0.1 mg L-1 were used for in vitro multiplication of three genotypes of wild Manihot species (M. violaceae Pohl Müll. Arg., M. pseudoglaziovii Pax & Hoff., and M. flabellifolia Pohl). Plant height and the number of 1 cm minicuttings, number of roots, shoots, green leaves and senescent leaves were recorded 120 days after explant inoculation. M. violaceae Pohl. Müll. Arg. and M. flabellifolia Pohl. presented favorable results with 0.05 and 0.025 mg L-1 NAA, respectively. Culture medium lacking NAA and BAP favored the in vitro growth of M. pseudoglaziovii Pax & Hoff.

Adjuvant interference on spray solution properties of 2, 4 - D and dicamba herbicides and their efficacy for Ipomoea SPP. control / Interferência de adjuvantes nas propriedades de calda dos herbicidas 2, 4 - D e dicamba e sua eficácia no controle de Ipomoea SPP

Synthetic auxin herbicides constitute major alternatives for managing tough-to-kill weeds such as Ipomoea spp. Adjuvant use is known to positively affect the biological efficacy of pesticides by modifying key spraying solution and droplet properties. Determining to what extent the use of adjuvants could change spray solution parameters and affect synthetic auxin herbicides' efficiency for Ipomoea spp. control were the research goals. The study was conducted in two phases: laboratory and field, respectively. In the laboratory, the pH, the surface tension, and the resources of the herbicide drops were measured. In the field, weed control was evaluated. All adjuvants modified spray solution properties, lowering surface tension values. Most adjuvants decreased pH values as well as number and density of droplets due to an increase in droplet size. Regardless of adjuvant usage, Ipomoea spp. control levels rose more rapidly following 2,4-D spraying rather than dicamba, resulting in lower biomass accumulation when the former was used. Dicamba-containing treatments displayed slightly but significantly lower Ipomoea spp. control levels at the end of the evaluation period. Herbicide efficacy for Ipomoea spp. control was not improved upon the addition to the spray solution of any of the tested adjuvants. Adjuvant use altered spraying solution and droplet properties. 2,4-D spraying allowed for lower Ipomoea spp. biomass and greater control levels relative to dicamba, suggesting it might constitute a better option for Ipomoea spp. control. Even though herbicide efficacy was not improved with adjuvants, their use should still be considered given favorable spraying solution alterations, mainly with some alteration in droplet sizes despite the use of similar spray nozzles tips - maintaining weed control efficacy.

Os herbicidas mimetizadores da auxina constituem alternativas importantes para o manejo de plantas daninhas de difícil controle, como Ipomoea spp. Sabe-se que o uso de adjuvante afeta positivamente a eficácia biológica dos pesticidas, modificando as principais propriedades da solução e do espectro de gotas da pulverização. Os objetivos desse trabalho foram determinar em que medida o uso de adjuvantes pode alterar os parâmetros da solução de pulverização e afetar a eficiência dos herbicidas mimetizadores da auxina para Ipomoea spp. Os estudos foram conduzidos em duas fases: em laboratório e em campo. Em laboratório foi avaliado o pH, tensão superficial e características das gotas dos herbicidas. Em campo foi avaliado o controle da planta daninha. Todos os adjuvantes modificaram as propriedades da solução de pulverização, diminuindo os valores de tensão superficial. A maioria dos adjuvantes diminuiu os valores de pH, bem como o número e a densidade de gotas. Independentemente do uso de adjuvante, os níveis de controle de Ipomoea spp. aumentaram mais rapidamente após a pulverização com 2,4-D do que com o dicamba, resultando em menor acúmulo de biomassa quando o primeiro foi usado. Os tratamentos contendo dicamba apresentaram ligeiramente menor controle de Ipomoea spp. A aplicação de 2,4-D promoveu menor biomassa e maiores níveis de controle em relação ao dicamba de Ipomoea spp., sugerindo que possa constituir uma opção melhor de controle. Embora a eficácia do herbicida não tenha sido melhorada com adjuvantes, seu uso ainda deve ser considerado com alterações favoráveis da solução de pulverização, principalmente tamanhos de gotas em qualquer uso de pontas de pulverização - mantendo a eficácia do controle de plantas daninhas.

miRNA-mediated regulation of auxin signaling pathway during plant development and stress responses

Auxin is one of the most important plant growth hormones, playing a crucial role in development as well as instress responses. Auxin biosynthesis and signaling pathway comprises a series of events including auxinperception by the receptor, activation, and function of auxin response factors and control by auxin repressors.All these factors are regulated by several different microRNAs during leaf, flower and fruit development,anther development, nodulation, lateral and adventitious root development, potato tuber development as wellas during heat stress, submergence, boron toxicity, aluminium stress responses, etc., as depicted in the availableliterature. In this review a thorough study on miRNA-mediated regulation of auxin biosynthesis and signalinghas been done in various plant species. The data gathered can be utilized to point out the particular miRNAmediated regulation module which can be utilized to modulate the expression of the miRNA and therebymodulation of the auxin pathway. Information in this review would be beneficial to utilize the miRNAexpression to generate the protocol for engineering plants with altered auxin signaling pathway to obtain betteryield and improved stress tolerance.

Simulated drift of dicamba and 2, 4-D on soybeans: effects of application dose and time / Deriva simulada de dicamba e 2, 4-D na soja: efeitos da dose de aplicação e tempo

The use of soybean varieties resistant to the herbicides dicamba and 2,4-D may lead to drifts towards areas grown with non-resistant varieties. The aim of this study was to evaluate the effects of dicamba and 2,4-D underdoses applied at the phenological stages V4 and R2 of soybeans. Two experiments were conducted with dicamba or 2,4-D in a randomized block design with four replications. The 4 × 2 + 1 factorial scheme was composed of four doses (0.028, 0.28, 2.8, and 28 g ae ha−1) of dicamba or 2,4-D applied at two phenological stages (V4 and R2) + a control treatment (without herbicide application). Dicamba underdoses caused damage to soybean crop affecting its vegetative growth and yield; the injuries caused by 2,4-D were neither enough to damage crop nor affect yield components. Dicamba underdoses applied at V4 caused injuries of up to 41%, while in R2 they reached 70%. Plant height decreased by up to 61% when treated with dicamba. Soybean yield was reduced by 29 and 76% when the simulated drift occurred at V4 and R2, respectively, and at a dose of 28 g ae ha−1 of dicamba. For the tested underdoses, only 2,4-D had no effect in soybean crop yield.

Com a inserção de variedades de soja resistentes aos herbicidas dicamba e 2,4-D os eventos de deriva destes herbicidas para áreas com variedades não resistentes será passível de ocorrência. Objetivou-se neste trabalho avaliar os efeitos de subdoses de dicamba e 2,4-D aplicados nos estádios fenológicos V4 e R2 da cultura da soja. Dois experimentos foram conduzidos com dicamba ou 2,4-D em delineamento experimental de blocos casualizados, com quatro repetições. Adotou-se o esquema fatorial de 4 x 2 + 1 composto por quatro doses (0,028, 0,28, 2,8 e 28 g ea ha-1) de dicamba ou de 2,4-D, aplicados em dois estádios fenológicos (V4 e R2) + um tratamento testemunha (sem aplicação de herbicida). As subdoses de dicamba provocaram danos na cultura da soja, afetando o desenvolvimento vegetativo e a produtividade, enquanto o 2,4-D não provocou injúrias suficientes para provocar danos que comprometessem a cultura, e desta forma, não afetou os componentes de produção. As subdoses de dicamba aplicadas no estádio V4 provocou injúrias de até 41%, enquanto em R2 chegaram a 70%. A altura das plantas reduziu em até 61% quando tratadas com dicamba. A produtividade da soja foi reduzida em 29 e 76%, quando a deriva simulada ocorreu nos estádios V4 e R2, respectivamente, e na dose de 28 g ea ha-1 de dicamba. Nas subdoses testadas somente o 2,4-D não afetou a produtividade da cultura da soja.

Cloning and Bioinformatic Analysis of ARPI Gene from Glycyrrhiza glabra / 中国实验方剂学杂志

Objective::To clone the complementary deoxyribonucleic acid (cDNA) of auxin/indole acetic acid protein (Aux/IAA) from Glycyrrhiza glabra (GgARPI) and analyze its sequence by bioinformatics. Method::RNA was extracted from fresh root of G. glabra, the cDNA sequence of GgARPI gene was cloned by reverse transcription polymerase chain reaction (RT-PCR), then sequencing and bioinformatic analysis were performed. Result::The GgARPI cDNA sequence with the full length of 686 bp was obtained from G. glabra. The full open reading frame (ORF) was 585 bp, encoding 194 amino acid residues. The bioinformatic analysis showed that the protein coded by GgARPI was a stable hydrophilic protein, with a relative molecular weight of 21.95 kDa and isoelectric point of 6.85.It contained no signal peptides or transmembrane domain. Its secondary structure mainly consisted of random coil. An Aux/IAA superfamily was included in the conversed domain. Homology analysis indicated that it had a close evolutionary relationship with leguminous plants, and a distant evolutionary relationship with monocotyledon, such as Setaria italica. Conclusion::GgARPI cDNA sequence is successfully cloned from G. glabra for the first time, which will lay a foundation for studying the function of GgARPI and explaining the molecular regulatory mechanism of biosynthesis of glycyrrhizic acid in G. glabra.

Agronomic performance of Marandu grass treated with plant growth biostimulants in the Amazon biome / Desempenho agronômico de capim-marandu tratado com bioestimulantes no bioma Amazônia

The aim was to evaluate the effect of different doses of two biostimulants on the productivity and canopy structure of Urochloa brizantha cv. Marandu grass in the establishment fase. The study was conducted in Universidade Federal Rural da Amazônia, Parauapebas, Pará, Brazil. One module of 35 plots of 25m² were established. A completely randomized experimental design was used, with seven treatments and five replicates. The treatments included a control, 0.5, 1, and 2kg/ha of biostimulant A (BIOST.A); and 0.25, 0.5, and 1L/ha of biostimulant B (BIOST.B). Three collections were performed. The data for application of the two biostimulants were analyzed separately, using the Dummy variable method and regression analysis. The application of 2kg/ha BIOST.A resulted in increases of 842kg/ha in the forage mass. The application of BIOST.B on Marandu grass resulted in a linear increase in stem mass. The application of 2kg/ha BIOST.A in the establishment of Marandu grass result in higher growth rates, forage accumulation, and stem proportion in the canopy.(AU)

Objetivou-se avaliar o efeito de diferentes doses de dois bioestimulantes sobre a produtividade e a estrutura do dossel do capim Urochloa brizantha cv. Marandu na fase de estabelecimento. O estudo foi realizado na Universidade Federal Rural da Amazônia, Parauapebas, Pará, Brasil. Um módulo de 35 parcelas de 25m² foi estabelecido. Utilizou-se delineamento experimental inteiramente ao acaso, composto de sete tratamentos e cinco repetições cada. Os tratamentos incluídos no controle foram: 0,5, 1 e 2kg/ha de bioestimulante A (BIOST.A); 0,25; 0,5 e 1L/ha de bioestimulante B (BIOST.B). Foram realizadas três coletas. Os dados para a aplicação dos dois bioestimulantes foram analisados separadamente, utilizando-se organização por método variável Dummy e análise de regressão. A aplicação de 2kg/ha BIOST.A resultou em incrementos de 842kg/ha na massa de forragem. A aplicação do BIOST.B na grama marandu resultou em aumento linear na produção de massa do caule. A aplicação de 2kg/ha BIOST.A no estabelecimento de erva de marandu resultou em maiores taxas de crescimento, acumulação de forragem e proporção de caule no dossel.(AU)

Use of plant growth regulators in fig tree seedling s 'roxo de valinhos' / Uso de reguladores vegetais em mudas de figueira 'Roxo de Valinhos'

The application of plant growth regulators can promote better development of the seedlings, essential for the success of fruit growing. The current study aims to evaluate the use of plant growth regulators in fig tree seedlings 'Roxo de Valinhos'. The experiment was carried out in a suspended nursery covered with plastic, using rooted cuttings of the cultivar Roxo de Valinhos. Four applications were made with a commercial product, known as Stimulate®, at doses of 0, 50, 100, 150, and 200 mL L-1. Using a randomized block experimental design, the study was subdivided into plots (doses X days of the last application [after 0, 7, 14 and 21]). The following traits were evaluated: stem and root length; stem diameter; root volume; leaf number; leaf area; stem, leaf and root dry mass; specific leaf area, leaf weight ratio; leaf area ratio; and chlorophyll total. Results indicated that the product promoted greater seedlings development at a dose range from 100 to 150 mL L-1. Different dose levels did not vary according to the days after product application. Furthermore, using such technique enabled seedlings of higher quality and vigour.

A aplicação de reguladores vegetais pode configurar uma técnica viável para promoção do melhor desenvolvimento das mudas, imprescindível para o sucesso da fruticultura. Deste modo, objetivou-se avaliar o uso de reguladores vegetais na produção de mudas da figueira 'Roxo de Valinhos'. O experimento foi realizado em viveiro suspenso com cobertura plástica, utilizando-se estacas enraizadas da cultivar Roxo de Valinhos. Foram realizadas quatro aplicações com o produto comercial Stimulate® nas concentrações de 0, 50, 100, 150, e 200 mL L-1. Utilizou-se o delineamento experimental em blocos casualizados com parcelas subdivididas [concentrações X épocas de avaliação (após 0, 7, 14 e 21 dias da última aplicação)]. Avaliou-se: comprimento do ramo e da maior raiz; diâmetro do ramo; volume de raízes; número de folhas e área foliar; massa seca de folhas, ramos e raízes; área específica foliar, razão de peso foliar e razão da área foliar; e teores de clorofila total. O uso do produto, nas concentrações de 100 a 150 mL L-1, promoveu maior desenvolvimento das mudas. O efeito das diferentes doses não variou em função dos dias após aplicação do produto. O uso de tal técnica permite a obtenção de mudas de maior qualidade e vigor.

EFFECT OF DIFFERENT SUBSTRATES AND AUXINS ON ROOTING OF Leucadendron sp. (PROTEACEAE) / EFECTO DE DIFERENTES SUSTRATOS Y AUXINAS EN EL ENRAIZAMIENTO DE Leucadendron sp. (PROTEACEAE)

ABSTRACT Colombian flower growers are faced with economic and social problems, so they are looking for alternatives, which include Proteas, ornamentals that require research that ensures an appropriate, local technical management. One of the Proteas most likely to be involved in this search is the genus Leucadendron. Therefore, this study aimed to establish the best basis for rooting its cuttings. The experimental design was a split plot design with a factorial arrangement. Four substrates were evaluated in combination with two auxins, naphthaleneacetic acid (NAA) and indolebutiric acid (IBA), three doses each, plus a commercial control. Each treatment was repeated three times and the experimental unit consisted of 30 stakes at the first locality and 25 at the second one. The most relevant results showed that vermiculite was the best substrate for rooting cuttings of Leucadendron at both localities. Also, it was identified that IBA is the growth regulator which improved the rooting percentage, the root volume, the stem decreased the percentage of losses.

RESUMEN Los cultivadores colombianos de flores tradicionales están confrontados con problemas, tanto económicos como sociales, por lo que están buscando alternativas, que incluyen a las Proteas, ornamentales que requieren investigación, que asegura un manejo técnico. Una de las Proteas con más posibilidad de estar involucrado en este desarrollo es el género Leucadendron. El diseño experimental empleado fue un diseño de parcelas, divididas con arreglo factorial. Así, que el objetivo de este estudio fue establecer la base para el enraizamiento de las estacas. En combinación con dos auxinas, ácido 1-naftalenacético (ANA) y ácido indolbutírico (AIB), tres dosis de cada una y el control comercial, se evaluaron cuatro sustratos. Cada tratamiento, se repitió tres veces y cada unidad experimental consistió en 30 estacas, para la primera localidad y de 25, para la segunda. Los resultados más relevantes mostraron que el mejor sustrato para el enraizamiento de estacas de Leucadendron fue la vermiculita, en ambas localidades. También, se identificó que AIB es el regulador de crecimiento que mejoró el porcentaje de enraizamiento, el volumen de raíces, la longitud del tallo disminuyó el porcentaje de pérdidas.

Transcriptomic analysis identifies differentially expressed genes (DEGs) associated with bolting and flowering in Saposhnikovia divaricata / 中国天然药物

Saposhnikovia divaricata is a valuable Chinese medicinal herb; the transformation from vegetative growth to reproductive growth may lead to the decrease of its pharmacological activities. Therefore, the study of bolting and flowering for Saposhnikovia divaricata is warranted. The present study aimed to reveal differentially expressed genes (DEGs) and regularity of expression during the bolting and flowering process, and the results of this study might provide a theoretical foundation for the suppression of early bolting for future research and practical application. Three sample groups, early flowering, flower bud differentiation, and late flowering (groups A, B, and C, respectively) were selected. Transcriptomic analysis identified 67, 010 annotated unigenes, among which 50, 165 were differentially expressed including 16, 108 in A vs B, and 17, 459 in B vs C, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway functional classification analysis were performed on these differentially expressed genes, and five important pathways were significantly impacted (P ≤ 0.01): plant circadian rhythm, other glycan degradation, oxidative phosphorylation, plant hormone signal transduction, and starch and sucrose metabolism. Plant hormone signal transduction might play an important role in the bolting and flowering process. The differentially expressed indole-3-acetic acid (IAA) gene showed significant down-regulation during bolting and flowering, while the transport inhibitor response 1 (TIR1) gene showed no significant change during the bolting process. The expression of flowering related genes FLC, LYF, and AP1 also showed a greater difference at different development stages. In conclusion, we speculate that the decrease in auxin concentration is not caused by the degrading effect of TIR1 but by an alternative mechanism.

Transcriptomic analysis identifies differentially expressed genes (DEGs) associated with bolting and flowering in Saposhnikovia divaricata / 中国天然药物

Saposhnikovia divaricata is a valuable Chinese medicinal herb; the transformation from vegetative growth to reproductive growth may lead to the decrease of its pharmacological activities. Therefore, the study of bolting and flowering for Saposhnikovia divaricata is warranted. The present study aimed to reveal differentially expressed genes (DEGs) and regularity of expression during the bolting and flowering process, and the results of this study might provide a theoretical foundation for the suppression of early bolting for future research and practical application. Three sample groups, early flowering, flower bud differentiation, and late flowering (groups A, B, and C, respectively) were selected. Transcriptomic analysis identified 67, 010 annotated unigenes, among which 50, 165 were differentially expressed including 16, 108 in A vs B, and 17, 459 in B vs C, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway functional classification analysis were performed on these differentially expressed genes, and five important pathways were significantly impacted (P ≤ 0.01): plant circadian rhythm, other glycan degradation, oxidative phosphorylation, plant hormone signal transduction, and starch and sucrose metabolism. Plant hormone signal transduction might play an important role in the bolting and flowering process. The differentially expressed indole-3-acetic acid (IAA) gene showed significant down-regulation during bolting and flowering, while the transport inhibitor response 1 (TIR1) gene showed no significant change during the bolting process. The expression of flowering related genes FLC, LYF, and AP1 also showed a greater difference at different development stages. In conclusion, we speculate that the decrease in auxin concentration is not caused by the degrading effect of TIR1 but by an alternative mechanism.

Drift of 2,4-D and dicamba applied to soybean at vegetative and reproductive growth stage / Deriva de 2,4-D e dicamba aplicado em estágio vegetativo e reprodutivo da soja

ABSTRACT: The introduction of dicamba and 2,4-D-resistant soybean will increase the use of auxin herbicides for management of herbicide-resistant weeds, increasing risk of drift in non-target crops. The field experiment was conducted in 2016/17 to evaluate injury, growth, yield, germination and seeds vigor of soybean effects to simulated drift of 2,4-D and dicamba applied to soybean at the V3 and R2 growth stages. To simulate drift, 2,4-D was applied at 0; 5.16; 10.4; 20.8 e 41.5g ae ha-1 and dicamba at: 0; 3.7; 7.4; 14.9 e 29.8g ae ha-1. The injury of the dicamba is greater than 2,4-D, and the V5 stage is more susceptible to both herbicides. The greatest reductions in soybean yield follow the drift of dicamba in R2 and 2,4-D in V5. The physiological quality seeds of the soybean is reduced by dicamba and 2,4-D drift at both the V5 and R2 stages of the soybean. Soybean is highly sensitive to low rates of 2,4-D and dicamba at the vegetative or reproductive growth stages. Dicamba causes greater negative effects than 2,4-D on soybean. The low rate of 2,4-D and dicamba reduce germination and vigor seed on soybean offspring.

RESUMO: A introdução de cultivares resistentes ao dicamba e 2,4-D aumentará o uso destes herbicidas para o manejo de ervas daninhas resistentes a herbicidas, aumentando o risco de deriva em culturas não-alvo. Assim, o objetivo do trabalho foi avaliar a fitotoxicidade, crescimento, produtividade, germinação e vigor de sementes de soja exposta deriva simulada de 2,4-D e dicamba nos estágios vegetativo e reprodutivo da soja. O experimento foi conduzido a campo na safra 2016/17. Para simular a deriva, 2,4-D foi aplicado nas doses de 0; 5,16; 10,4; 20,8 e 41,5g e.a. ha-1 e dicamba nas doses de 0; 3,7; 7,4; 14,9 e 29,8g e.a. ha-1. A fitotoxicidade de dicamba é maior que 2,4-D, sendo o estágio V5 mais suscetível para ambos herbicidas. As maiores reduções na produtividade da soja sucedem a deriva de dicamba em R2 e 2,4-D em V5. A qualidade fisiológica das sementes de soja é reduzida em função da deriva de dicamba e 2,4-D em aplicação nos ambos estágios V5 e R2 da soja. A soja é altamente sensível a baixas concentrações de 2,4-D e dicamba nos estágios vegetativo e reprodutivo. O dicamba causa maiores efeitos negativos comparado com 2,4-D. Baixas concentrações de 2,4-D e dicamba reduzem germinação e vigor de sementes de soja.

Enraízamíento de esquejes de Caña Agria (Cheilocostus speciosus. J. Koenig) / Rooting of cuttings of Sour cane (Cheilocostus speciosus. J. Koenig)

RESUMEN La Caña Agria (Cheilocostus speciosus. J. Koenig) es una planta floral decorativa, usada en la producción de artesanías derivadas de la Caña Flecha (Gynerium sagittatum. Aubl.), en los municipios de San Andrés de Sotavento y Tuchín, del departamento de Córdoba en Colombia, por sus propiedades para el blanqueamiento de fibras de Caña Flecha. Debido a la escasa presencia de plantas de Caña Agria en los resguardos indígenas de Túchin y San Andrés de Sotavento, se consideró necesario investigar nuevos métodos de propagación con el objetivo de conformar bancos de semillas que permitan aumentar la disponibilidad de material vegetal. Para ello, se seleccionaron esquejes de tallo de aproximadamente 11 cm de longitud, y se evaluó el efecto de tres concentraciones (0,0; 500 y 1000 mg-L-1 de ANA), sobre el enraizamiento. Los esquejes se colocaron en cada concentración por 10 días, y transcurrido el tiempo, se pasaron a bandejas con tierra en condiciones semicontroladas de temperatura y humedad. 30 días posteriores al trasplante, se establecieron los porcentajes de sobrevivencia y de enraizamiento de los esquejes. Como resultado, se encontró que los tratamientos con ANA aumentan la formación de raíces. El mejor tratamiento para enraizar esquejes fue el de 500 mg-L-1, con un porcentaje de enraizamiento del 96% a los 10 días después de la inducción. Por otra parte, Los tratamientos correspondientes a 0,0 mg-L-1 y 1000 mg-L-1 generaron porcentajes de enraizamiento del 24% y 70% respectivamente. El mayor número de raíces por planta con promedio de 8,76, se obtuvo en la solución 500 mg-L-1 de ANA.

ABSTRACT The Caña Agria (Cheilocostus speciosus, J. Koenig) is a decorative floral plant, used in the production of handicrafts derived from the Cane Flecha (Gynerium sagittatum, Aubl.), in the municipalities of San Andrés de Sotavento and Túchin, department of Córdoba in Colombia, for its properties for the fiber whitening of Caña Flecha. Due to the scarce presence of Caña Agria plants in the indigenous reserves of Túchin and San Andrés de Sotavento, it was considered necessary to investigate new methods of propagation with the objective of forming seed banks that allow to increase the availability of plant material. To do this, stem cuttings of approximately 11 cm in length were selected, and the effect of three concentrations (0.0, 500 and 1000 mg L-1 of ANA) was evaluated on the rooting. The cuttings were placed in each concentration for 10 days, and after the time, they were transferred to trays with soil under semicontrolled conditions of temperature and humidity. 30 days after the transplant, the percentage of survival and rooting of the cuttings were established. As a result, it was found that ANA treatments increase root formation. The best treatment to root cuttings was the 500 mg L-1, with a percentage of rooting of 96% at 10 days after induction. On the other hand, the treatments corresponding to 0.0 mg L-1 and 1000 mg L-1 generated percentages of rooting of 24% and 70% respectively. The highest number of roots per plant with an average of 8.76 was obtained in the 500 mg L-1 ANA solution.

Vegetative rescue and ex vitro system production of Tibouchina sellowiana clonal plants by cutting and mini-cutting / Resgate vegetativo e sistema ex vitro de produção de mudas de Tibouchina sellowiana por estaquia e miniestaquia

ABSTRACT: We aimed to evaluate the rooting potential of Tibouchina sellowiana through the experiments: I - Cuttings from current-year shoots and epicormic shoots were submitted to IBA concentrations: 0, 500, 1000, 1500 and 2000mg L-1, in a factorial arrangement 2 x 5 (two types of cuttings x five IBA concentrations), with four replicates and 20 cuttings each; II - mini-stumps of Tibouchina sellowiana were submitted to successive shoots collecting during the four seasons, in a split-plot design, with five replications of ten mini-stumps per experimental unit. From the shoots of mini-stumps, mini-cuttings were produced, which were initially kept in greenhouse and later transferred to full sun, in a 4 x 5 factorial arrangement (four seasons x five collections per season), with four replicates of 12 mini-cuttings. Superiority of epicormic shoots cuttings was reported when compared to the current-year shoots, which showed the highest rooting and leaves maintenance (42.50% and 55.00%, respectively), eliminating the use of IBA. High survival of mini-stumps (over 80%) and the mini-cuttings production (170mini-cuttings m-2 month-1) in clonal mini-garden and the mini-cuttings survival (above 80%) in the greenhouse demonstrated the technical feasibility, with summer as the most appropriate time to collect mini-cuttings.

RESUMO: Objetivou-se avaliar o potencial de enraizamento de Tibouchina sellowiana por meio dos experimentos: I - Estacas provenientes de brotações do ano e epicórmicas foram submetidas às concentrações de IBA: 0, 500, 1000, 1500 e 2000mg L-1, em arranjo fatorial 2 x 5 (dois tipos de estacas x cinco concentrações de IBA), com quatro repetições de 20 estacas cada; II - Minicepas de Tibouchina sellowiana foram submetidas à coletas sucessivas de suas brotações durante as quatro estações do ano, em modelo de parcelas subdivididas no tempo, com cinco repetições de dez minicepas por unidade experimental. A partir das brotações das minicepas foram produzidas miniestacas, as quais foram inicialmente mantidas em casa de vegetação e posteriormente transferidas para pleno sol, em arranjo fatorial 4 x 5 (quatro estações do ano x cinco coletas por estação), com quatro repetições de 12 miniestacas. Verificou-se superioridade das estacas de brotações epicórmicas em comparação às brotações do ano, as quais apresentaram o maior enraizamento e retenção foliar (42,50% e 55,00%, respectivamente), dispensando o uso de IBA. A elevada sobrevivência das minicepas (superior a 80%) e produção de miniestacas (170 miniestacas m-2 mês-1) em minijardim clonal e sobrevivência (acima de 80%) de miniestacas em casa de vegetação demonstram a viabilidade da técnica, sendo o verão a época mais adequada para coleta de miniestacas.

Indoleacetic acid production and chromium reduction by cyanobacteria Synechocystis SP. P2A (Chroococcales) immobilized in alginate beads / Produção de ácido indolacético e redução do cromo por cianobactérias Synechocystis SP. P2A (Chroococcales) imobilizadas em esferas de alginato

A simple extrusion method was used to entrap Synechocystis sp.P2A in alginate beads. The viability, growth response and Indoleacetic acid (IAA) production at different pH were studied in alginate immobilized Synechocystis sp.P2A. 2.6% sodium alginate (w/v) and pH-7 was found to be optimum for growth of Synechocystis sp. P2A as well as IAA production (79µg/ml). To prepare effective formulation for plant inoculation, alginate beads were further modified by coating with chitosan or chitosan-polyethylene glycol. Effect of all formulations containing Synechocystis sp. P2A in free and immobilized form on growth of Triticumaestivum was evaluated. Soil inoculation of entrapped Synechocystis in alginate beads coated with chitosan resulted in 20% increase in root length and 14% increase in dry weight as compared to non-inoculated seedlings. Free and immobilized cyanobacteria were allowed to grow in BG11 medium supplemented with 100µg/ml K2CrO4 and chromium reduction was measured at variable pH. At pH 7 immobilized showed 5% more reduction than free form. The current study showed that alginate immobilized Synechocystis sp. P2A can accomplish viable functions including plant growth promoting hormone production and chromium reduction and therefore propose an efficient and convenient method for storage and use of cyanobacteria.

Um método de extrusão simples foi utilizado para aprisionar Synechocystis sp.P2A em esferas de alginato. A viabilidade, a resposta ao crescimento e a produção de ácido indolacético (IAA) a diferentes pH foram estudadas na Synechocystis sp.P2A imobilizada com alginato. Alginato de sódio a 2,6% (p/v) e pH-7 revelou-se ótimo para o crescimento de Synechocystis sp. P2A, bem como para a produção de IAA (79 µg/ml). Para preparar uma formulação eficaz para inoculação de plantas, as esferas de alginato foram adicionalmente modificadas por revestimento com quitosano ou quitosano-polietileno glicol. O efeito de todas as formulações contendo Synechocystis sp. P2A em forma livre e imobilizada no crescimento de Triticumaestivum foi avaliado. A inoculação no solo com Synechocystis aprisionado em esferas de alginato revestidas com quitosano resultou em um aumento de 20% no comprimento da raiz e aumento de 14% no peso seco em comparação com mudas não inoculadas. As cianobactérias livres e imobilizadas foram deixadas crescer em meio BG11 suplementado com 100 µg/ml de K2CrO4 e a redução do cromo foi medida a um pH variável. A um pH 7 a forma imobilizada apresentou 5% mais de redução do que a forma livre. O presente estudo mostrou que o alginato imobilizado de Synechocystis sp. P2A pode realizar funções viáveis, incluindo a produção de hormônio promotor do crescimento de plantas e redução de cromo e, portanto, propor um método eficiente e conveniente para armazenamento e uso de cianobactérias.

Expression analysis of polar auxin transport mediated gene PIN in Panax ginseng / 药学学报

Polar auxin transport gene PIN (PIN-FORMED) determines the concentration gradient of auxin and plays an important role in development and secondary metabolism of plants. This study was designed to analyze the bioinformatics and expression of the PIN genes in Panax ginseng to explore a novel way of breeding ginseng varieties. Heatmap and cluster analysis of PIN2, PIN3, PIN6 was performed in four-year-old Jilin ginseng. Sequence homology alignment, RT-PCR amplification, sequencing and bioinformatics analysis were used to identify three PIN family genes PgPIN2, PgPIN3 and PgPIN6 in P. ginseng. PIN expression in ginseng adventitious root and culture seedling was analyzed with qRT-PCR technique. Results suggested that in ginseng adventitious root tip, PgPIN3 and PgPIN6 exhibited a high level of expression; in ginseng culture seedling root, PgPIN2 showed a high level of expression; in four-year-old Jilin ginseng at the fruit ripening stage, PgPIN2 and PgPIN6 were highly expressed in root and rhizome, while PgPIN3 had a high level in ginseng leaf, fruit and root. Tissue specific expression profile showed that PgPIN2 and PgPIN6 probably were involved in the development and tropism growth in ginseng roots, while PIN3 might be in relation to the growth and development of the aerial part of plants.

Root development in Bupleurum chinense and its impact factors / 中草药

Objective To identificate the development process and impact factors of lateral root in Bupleurum chinense. Methods The dynamic growth of lateral root primordia was observed by applying paraffin sectioning, and by light microscopy. In addition, the influence of growth regulators treatment on lateral root growth was also investigated. Results The lateral root primordium formation of B. chinense started near the pericycle cells, part of the endodermis cells also participated in this formation; 10 μmol/L IAA and Ca2+ greatly promoted the development of lateral root, but its high concentration inhibited lateral root emergence; 0.1 μmol/L TIBA and 10 μmol/L EDTA promoted the development of lateral root, but its high concentration inhibited lateral root emergence. Conclusion This research method can also be applied in other pharmaceutical plants, such as Angelica sinensis and Panax ginseng. So the study is very important to medicinal plant cultivation and breeding.

Interactions between plant hormones and heavy metals responses

Abstract Heavy metals are natural non-biodegradable constituents of the Earth's crust that accumulate and persist indefinitely in the ecosystem as a result of human activities. Since the industrial revolution, the concentration of cadmium, arsenic, lead, mercury and zinc, amongst others, have increasingly contaminated soil and water resources, leading to significant yield losses in plants. These issues have become an important concern of scientific interest. Understanding the molecular and physiological responses of plants to heavy metal stress is critical in order to maximize their productivity. Recent research has extended our view of how plant hormones can regulate and integrate growth responses to various environmental cues in order to sustain life. In the present review we discuss current knowledge about the role of the plant growth hormones abscisic acid, auxin, brassinosteroid and ethylene in signaling pathways, defense mechanisms and alleviation of heavy metal toxicity.