Drought is one of the most stressful environmental factor causing yield and economic losses in many soybean-producing regions. In the last decades, transcription factors (TFs) are being used to develop genetically modified plants more tolerant to abiotic stresses. Dehydration responsive element binding (DREB) and ABA-responsive element-binding (AREB) TFs were introduced in soybean showing improved drought tolerance, under controlled conditions. However, these results may not be representative of the way in which plants behave over the entire season in the real field situation. Thus, the objectives of this study were to analyze agronomical traits and physiological parameters of AtDREB1A (1Ab58), AtDREB2CA (1Bb2193), and AtAREB1 (1Ea2939) GM lines under irrigated (IRR) and non-irrigated (NIRR) conditions in a field experiment, over two crop seasons and quantify transgene and drought-responsive genes expression. Results from season 2013/2014 revealed that line 1Ea2939 showed higher intrinsic water use and leaf area index. Lines 1Ab58 and 1Bb2193 showed a similar behavior to wild-type plants in relation to chlorophyll content. Oil and protein contents were not affected in transgenic lines in NIRR conditions. Lodging, due to plentiful rain, impaired yield from the 1Ea2939 line in IRR conditions. qPCR results confirmed the expression of the inserted TFs and drought-responsive endogenous genes. No differences were identified in the field experiment performed in crop season 2014/2015, probably due to the optimum rainfall volume during the cycle. These field screenings showed promising results for drought tolerance. However, additional studies are needed in further crop seasons and other sites to better characterize how these plants may outperform the WT under field water deficit.

Although the information on the Normalized Difference Vegetation Index (NDVI) in plants under water deficit is often obtained from sensors attached to satellites, the increasing data acquisition with portable sensors has wide applicability in agricultural production because it is a fast, nondestructive method, and is less prone to interference problems. Thus, we carried out a set of experiments to investigate the influence of time, spatial plant arrangements, sampling size, height of the sensor and water regimes on NDVI readings in different soybean cultivars in greenhouse and field trials during the crop seasons 2011/12, 2012/13 and 2013/14. In experiments where plants were always evaluated under well-watered conditions, we observed that 9 a.m. was the most suitable time for NDVI readings regardless of the soybean cultivar, spatial arrangement or environment. Furthermore, there was no difference among NDVI readings in relation to the sampling size, regardless of the date or cultivar. We also observed that NDVI tended to decrease according to the higher height of the sensor in relation to the canopy top, with higher Electronic supplementary material The online version of this article (values tending to be at 0.8 m, but with no significant difference relative to 1.0 m-the height we adopted in our experiments. When different water regimes were induced under field conditions, NDVI readings measured at 9 a.m. by using a portable sensor were successful to differentiate soybean cultivars with contrasting responses to drought.

INTRODUÇÃOA soja é a principal oleaginosa cultivada no mundo, sendo a cultura agrícola brasileira que apresentou maior crescimento, nas últimas décadas, ocupando, aproximadamente, 50% da área agrícola plantada (Conab 2013), o que contribui, significativamente, para a economia do País. Dentre os fatores que contribuem para assegurar o bom desempenho da cultura, está a utilização de sementes de alta qualidade, capazes de proporcionar adequado estabelecimento da cultura no campo. ABSTRACT RESUMOA qualidade de um lote de sementes é determinada pela sua condição genética, sanitária, física e fisiológica. A caracterização da qualidade fisioló-gica das sementes é baseada, fundamentalmente, no teste de germinação, o qual já possui metodologia padronizada. Porém, por ser conduzido em condições ideais, o teste possui limitações, como a inabilidade para detectar diferenças de qualidade entre lotes com alta germinação (Hampton & Tekrony 1995). Neste sentido, para a avaliação da qualidade fisiológica de sementes, de forma ampla e segura, é necessária a Use of bioactivator, biostimulant and complex of nutrients in soybean seeds New discoveries have stimulated the use of different substances with physiologic effects, in order to develop agricultural crops. Thus, this study aimed at evaluating seeds treated with biostimulant, bioactivator and nutrients, in the initial development of soybean seeds. Two lots of seeds (high and low vigor, BMX Potência RR cultivar) were used. The products tested were an insecticide with bioactivator effect, a plant growth regulator with biostimulant effect, a complex of nutrients and a control. Under laboratory conditions, the parameters water content, germination, first germination counting, accelerated aging, cold test, length and dry matter weight of seedlings were evaluated. Under greenhouse conditions, evaluations included emergence, emergence speed index, length and dry matter weight of seedlings. The efficiency of the products tested was affected by the seed physiologic quality, with a more pronounced effect for the products in high vigor lots. In general, the treatment with best results for initial performance was the complex of nutrients, followed by the plant growth regulator with biostimulant effect. The bioactivator had negative effect on seeds germination and seedling development. KEY-WORDS:Glycine max L.; seed vigor; seed treatment.

A variety of cellular responses is needed to ensure the plants survival during drought, but little is known about the signaling mechanisms involved in this process. Soybean cultivars (EMBRAPA 48 and BR 16, tolerant and sensitive to drought, respectively) were exposed to the following treatments: control conditions (plants in field capacity), drought (20% of available water in the soil), sodium nitroprusside (SNP) treatment (plants irrigated and treated with 100‐µM SNP [SNP–nitric oxide (NO) donor molecule], and Drought + SNP (plants subjected to drought and SNP treatment). Plants remained in these conditions until the reproductive stage and were evaluated for physiological (photosynthetic pigments, chlorophyll a fluorescence and gas exchange rates), hydraulic (water potential, osmotic potential and leaf hydraulic conductivity) and morpho‐anatomical traits (biomass, venation density and stomatal characterization). Exposure to water deficit considerably reduced water potential in both cultivars and resulted in decrease in photosynthesis and biomass accumulation. The addition of the NO donor attenuated these damaging effects of water deficit and increased the tolerance index of both cultivars. The results showed that NO was able to reduce plant's water loss, while maintaining their biomass production through alteration in stomatal characteristics, hydraulic conductivity and the biomass distribution pattern. These hydraulic and morpho‐anatomical alterations allowed the plants to obtain, transport and lose less water to the atmosphere, even in water deficit conditions.

NMR and chromatography methods combined with mass spectrometry are the most important analytical techniques employed for plant metabolomics screening. Metabolomic analysis integrated to transcriptome screening add an important extra dimension to the information flow from DNA to RNA to protein. The most useful NMR experiment in metabolomics analysis is the proton spectra due the high receptivity of 1 H and important structural information, through proton-proton scalar coupling. Routinely, databases have been used in identification of primary metabolites, however, there is currently no comparable data for identification of secondary metabolites, mainly, due to signal overlap in normal 1 H NMR spectra and natural variation of plant. Related to spectra overlap, alternatively, better resolution can be find using 1 H pure shift and 2D NMR pulse sequence in complex samples due to spreading the resonances in a second dimension. Thus, in data brief we provide a catalogue of Contents lists available at ScienceDirect

Soybean production both in Brazil and globally has regularly been threatened by drought periods. The use of infrared thermography to evaluate the canopy's temperature and its relationship with plant water status constitutes an important tool for agricultural monitoring. However, studies regarding the water status of soybean plants through unmanned aerial vehicle (UAV)-based thermal imaging are yet to be reported. Thus, the present study aimed to evaluate the water status of soybean plants submitted to different water conditions via thermal images obtained through an UAV thermal infrared camera. The field experiment was undertaken at the National Soybean Research Centre (Embrapa Soja, a branch of the Brazilian Agricultural Research Corporation) in a randomized complete block design, with four replicates. The following water conditions were evaluated: irrigated (IRR, receiving rainfall and irrigation when necessary, and with a soil water matric potential between −0.03 MPa and −0.05 MPa), non-irrigated (NIRR, receiving only rainfall), and water deficit (or drought stress) induced at the vegetative (DSV) and reproductive (DSR) stages. Water deficit was induced using rainout shelters. Soil moisture and weather data were monitored daily. Thermal images were obtained on twelve dates, half in 2016-2017 and half during the 2017-2018 crop seasons, through a thermal infrared camera (DIY-Thermocam) sensitive to temperatures ranging from -40°C to 200°C, with 0.5 °C accuracy and 14-bit radiometric resolution. Images in RAW format (160 pixels x120 pixels) were obtained at 125 m above ground level. They were then processed and calibrated by acquiring a correction factor resulting from the effect of atmospheric attenuation. The canopy temperature was evaluated in relation to that of air temperature and through the Normalized Relative Canopy Temperature (NRCT). Atmospheric attenuation was positively correlated to flight altitude, so that image correction eliminated such an effect. The thermal behaviour of soybean plants was directly correlated to soil water availability and atmospheric vapour pressure deficit, with differences ranging from 0.2 °C to 7.2°C. Plants grown at lower soil moisture conditions had higher temperatures, which were

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-This study aimed at evaluating the relationship among lignin content in the seed coat of soybean seeds with tolerance to weathering damage and oxidative stress. Four soybean cultivars (CD 208, CD 215, CD 202 and BRS 184), with lignin contents in the seed coat of 4.2, 2.6, 2.0 and 1.7%, respectively, were used. Seeds were subjected to deterioration by moisture, through artificially simulated rains. Pods of all cultivars were subjected to irrigation by constant sprinkling during 4 hours, and then dried in oven, set at 35 °C, for 37 hours; repeating twice such procedure. After these treatments seeds were subjected to tests and then compared to the control. Tests performed were: germination, accelerated aging and tetrazolium test; thereby quantifying the occurrence of damages by weathering damage. The activity of enzymes superoxide dismutase and guaiacol peroxidase was measured; and the lipid peroxidation was assessed. Soybean cultivars CD 208 and CD 215, with higher lignin content in the seed coat, were less susceptible to weathering damage. Seeds of cultivar CD 208 have also presented lower oxidative stress, when subjected to weathering damage stress.Index terms: Glycine max. L, field deterioration, seed quality.Suscetibilidade à deterioração por umidade e ao estresse oxidativo em sementes de soja com variação no conteúdo de lignina no tegumento RESUMO -O estudo teve como objetivo avaliar a relação entre o teor de lignina no tegumento de sementes de soja com tolerância à deterioração por umidade e ao estresse oxidativo. Foram utilizadas quatro cultivares de soja: CD 208, CD 215, CD 202 e BRS 184, com teores de lignina no tegumento de 4,2; 2,6; 2,0 e 1,7%, respectivamente. As sementes foram submetidas a uma deterioração por umidade através de chuvas simuladas (4 horas), e, posteriormente, secas em estufa (35 °C), por 37 horas, totalizando dois ciclos de umedecimento e secagem. Foram realizados os testes: germinação, envelhecimento acelerado e teste de tetrazólio. Foi medida a atividade das enzimas antioxidantes: Superóxido Dismutase e Guaiacol Peroxidase; e a peroxidação lipídica. As avaliações foram realizadas no delineamento inteiramente casualizado, em esquema fatorial 2x4, com quatro repetições. As cultivares de soja CD 208 e CD 215, com maior teor de lignina no tegumento, são menos suscetíveis ao dano por umidade. As sementes da cultivar CD 208 também apresentaram menor estresse oxidativo, quando submetidas a deterioração por umidade.Termos para indexação: Glycine max. L, deterioração em campo, qualidade de sementes.