Cloning and functional verification of PhAEP gene, a key enzyme for biosynthesis of heterophyllin A in Pseudostellaria heterophylla / 中国中药杂志

This paper aimed to study the role of asparagine endopeptidase(AEP) gene in the biosynthesis mechanism of cyclic peptide compounds in Pseudostellaria heterophylla. The transcriptome database of P. heterophylla was systematically mined and screened, and an AEP gene, tentatively named PhAEP, was successfully cloned. The heterologous function verification by Nicotiana benthamiana showed that the expression of the gene played a role in the biosynthesis of heterophyllin A in P. heterophylla. Bioinformatics analysis showed that the cDNA of PhAEP was 1 488 bp in length, encoding 495 amino acids with a molecular weight of 54.72 kDa. The phylogenetic tree showed that the amino acid sequence encoded by PhAEP was highly similar to that of Butelase-1 in Clitoria ternatea, reaching 80%. The sequence homology and cyclase active site analysis revealed that the PhAEP enzyme may specifically hydrolyse the C-terminal Asn/Asp(Asx) site of the core peptide in the HA linear precursor peptide of P. heterophylla, thereby participating in the ring formation of the linear precursor peptide. The results of real-time quantitative polymerase chain reaction(RT-qPCR) showed that the expression level of PhAEP was the highest in fruits, followed by in roots, and the lowest in leaves. The heterophyllin A of P. heterophylla was detected in N. benthamiana that co-expressed PrePhHA and PhAEP genes instantaneously. In this study, the PhAEP gene, a key enzyme in the biosynthesis of heterophyllin A in P. heterophylla, has been successfully cloned, which lays a foundation for further analysis of the molecular mechanism of PhAEP enzyme in the biosynthesis of heterophyllin A in P. heterophylla and has important significance for the study of synthetic biology of cyclic peptide compounds in P. heterophylla.

Distinguishing between Artemisia stolonifera and A. argyi by specific PCR of leaves and non-glandular trichomes / 中国中药杂志

Artemisia stolonifera is a relative of A. argyi. The two species are difficult to be distinguished due to the similarity in leaf shape and have even less distinctive features after processing. This study aims to establish a method to quickly distinguish between them. At the same time, we examined the reasonability and applicability of the specific polymerase chain reaction(PCR) method. The C/T single nucleotide polymorphism was detected at the position 202 of the sequence, based on which specific primers were designed to identify these two species. The PCR with the specific primer JNC-F and the universal primer ITS3R produced a specific band at 218 bp for A. argyi and no band for A. stolonifera, which can be used to detect at least 3% of A. argyi samples mixed in A. stolonifera samples. The PCR with the specific primer KY-F and the universal primer ITS3R produced a specific band at 218 bp for A. stolonifera and no band for A. argyi, which can be used to detect at least 5% of A. stolonifera samples mixed with A. argyi. The limit of detection of the established method was 5 ng DNA. The established PCR method can accurately distinguish between A. stolonifera and A. argyi, which provides an experimental basis for the quality control of A. stolonifera and determines whether the herbs are adulterated.

Screening of reference genes for quantitative real-time PCR in Artemisia argyi / 中国中药杂志

Artemisia Argyi Folium, a traditional Chinese medicine of important medicinal and economic value, sees increasing demand in medicinal and moxibustion product market. Screening stable and reliable reference genes for quantitative real-time PCR(qRT-PCR) is a prerequisite for the analysis of gene expression in Artemisia argyi. In this study, eight commonly used reference genes, Actin, 18s, EF-1α, GAPDH, SAND, PAL, TUA, and TUB, from the transcriptome of A. argyi, were selected as candidate genes. The expression of each gene in different tissues(roots, stems, and leaves) of A. argyi and in leaves of A. argyi after treatment with methyl jasmonate(MeJA) for different time(0, 4, 8, 12 h) was detected by qRT-PCR. Then, geNorm, NormFinder, BestKeeper, ΔCT, and RefFinder were employed to evaluate their expression stability. The results demonstrated that Actin was the most stable reference gene in different tissues and in leaves treated with MeJA, and coming in the second was SAND. Furthermore, the expression of DXS and MCT which are involved in terpenoid backbone biosynthesis was detected in different tissues and after MeJA treatment. The results showed that the expression patterns of DXS and MCT in different tissues and under MeJA treatment calculated with Actin and SAND as internal reference genes were consistent, which validated the screening results. In conclusion, Actin is the most suitable reference gene for the analysis of gene expression in different tissues of A. argyi and after MeJA treatment. This study provides valuable information for gene expression analysis in A. argyi and lays a foundation for further research on molecular mechanism of quality formation of Artemisia Argyi Folium.

Genome-wide identification of CsCCD gene family in tea plant (Camellia sinensis) and expression analysis of the oolong tea processing with supplementary LED light / 生物工程学报

Carotenoid cleavage dioxygenase (CCD) family is important for production of volatile aromatic compounds and synthesis of plant hormones. To explore the biological functions and gene expression patterns of CsCCD gene family in tea plant, genome-wide identification of CsCCD gene family was performed. The gene structures, conserved motifs, chromosome locations, protein physicochemical properties, evolutionary characteristics, interaction network and cis-acting regulatory elements were predicted and analyzed. Real time-quantitative reverse transcription PCR (RT-qPCR) was used to detect the relative expression level of CsCCD gene family members under different leaf positions and light treatments during processing. A total of 11 CsCCD gene family members, each containing exons ranging from 1 to 11 and introns ranging from 0 to 10, were identified. The average number of amino acids and molecular weight were 519 aa and 57 643.35 Da, respectively. Phylogenetic analysis showed the CsCCD gene family was clustered into 5 major groups (CCD1, CCD4, CCD7, CCD8 and NCED). The CsCCD gene family mainly contained stress response elements, hormone response elements, light response elements and multi-factor response elements, and light response elements was the most abundant (142 elements). Expression analysis showed that the expression levels of CsCCD1 and CsCCD4 in elder leaves were higher than those in younger leaves and stems. With the increase of turning over times, the expression levels of CsCCD1 and CsCCD4 decreased, while supplementary LED light strongly promoted their expression levels in the early stage. The expression level of NCED in younger leaves was higher than that in elder leaves and stems on average, and the expression trend varied in the process of turning over. NCED3 first increased and then decreased, with an expression level 15 times higher than that in fresh leaves. In the late stage of turning over, supplementary LED light significantly promoted its gene expression. In conclusion, CsCCD gene family member expressions were regulated by mechanical force and light. These understandings may help to optimize tea processing techniques and improve tea quality.

Effects of density on growth and gene transcription characteristics of Rehmannia glutinosa / 中国中药杂志

The present study analyzed the effects of planting density on the development, quality, and gene transcription characte-ristics of Rehmannia glutinosa using 85-5 and J9 as materials with three planting densities of 5 000, 25 000, and 50 000 plants/Mu(1 Mu≈667 m~2). The agronomic characteristics of leaves and tuberous roots, the content of catalpol and acteoside, and the changes of gene expression were determined. The results showed that the leaf size, the diameter of tuberous root, leaf biomass, tuberous root number, and tuberous root biomass per plant at low density were significantly higher than those of medium and high densities. The content of catalpol and acteoside in leaves was higher at high density. The content of catalpol in tuberous roots was higher at low density, and the change trend was similar to that in leaves, while the content of acteoside in tuberous roots was higher at high density. Transcriptome analysis found that about 1/2 of the expansin genes could change regularly in response to density treatment, which was rela-ted to the development of tuberous roots. The change trend of the gene expression of multiple catalytic enzymes involved in the biosynthesis of catalpol and acteoside was consistent with that of their content, which was presumedly involved in the accumulation and regulation of density-responsive medicinal components. Based on the analysis of the development, medicinal components, and gene expression characteristics of R. glutinosa at different densities, this study is expected to provide an important basis for regulating the quality and yield of medicinal materials of R. glutinosa by managing the planting density.

Correlation analysis and breeding application of agronomic traits and quality indexes in Dendrobium nobile / 中国中药杂志

The present study aimed to explore the correlation between agronomic traits and quality indexes of Dendrobium nobile and its application value in agricultural breeding. The cultivated strains of D. nobile in Hejiang-Chishui producing areas were extensively collected,and the main agronomic traits and quality indexes were measured. The agronomic traits with significant correlation with quality indexes were screened out by the correlation analysis,and then the parental lines and self-bred F_1 generation plants were furtherverified. Among 96 lines of D. nobile,the content of soluble polysaccharides showed a significant negative correlation with dendrobine( P < 0. 01),and no significant correlation with agronomic traits in stems and leaves. The content of dendrobine exhibited a significant positive correlation with the stem width-thickness ratio( at the largest cross section; P < 0. 01),and no significant correlation with other agronomic traits. Regression analysis further verified the positive correlation between dendrobine content and stem width-thickness ratio( R2> 0. 9). Two lines,JC-10 and JC-35,with significant differences in stem width-thickness ratio were screened out( P <0. 05). The corresponding F1 generation plants by self-pollination both showed that the dendrobine content was higher with greater stem width-thickness ratio( P < 0. 01). The experimental results suggested that within a certain range,the dendrobine content was higher in D. nobile with flatter stem. Therefore,in the breeding of D. nobile,this specific trait could be used for screening plants with high content of quality indexes such as dendrobine.

Diversity of Artemisia argyi germplasm resources based on agronomic and leaf phenotypic traits / 中国中药杂志

In this study, in order to evaluate the phenotypic diversity of Artemisia argyi germplasm resources and improve its efficiency of cultivation and breeding, 100 accessions of A. argyi germplasm resources from 58 regions in China were collected, 20 agronomic traits and leaf phenotypic traits were observed and described. The data were used for phenotypic diversity analysis, correlation analysis, principal component analysis and cluster analysis. The result showed that the genetic diversity index of 20 traits ranged from 0.82 to 4.37, among which the largest was the base depth and the smallest was the leaf width; the coefficient of variation of the 12 quantitative traits ranged from 10.55% to 41.47%. the highest coefficient of variation was the height of dead leaves, and the smallest was the content of chlorophyll, except for the angle of branches, all the quantitative characters tended to be normal distribution. The correlation analysis showed that 28 pairs of traits had significant correlation(P<0.01), and 13 pairs had significant correlation(P<0.05). According to principal component analysis, 20 traits were simplified into 9 principal components, and the cumulative contribution rate was 73.414%, nine traits including plant height, dead leaves heigh, stem diameter, symmetry of leave base, stipule, leaf tip shape, depth of the first pair of lobes, depth of the second pair of lobes and leaf yield were selected as key indexes for evaluating agronomic traits and leaf phenotypic traits of A.argyi germplasm resources. With cluster analysis, 100 accessions of A.argyi were classified into 3 groups, the groupⅠincluded the dwarf plants with thick stem and large leaf, the groupⅡincluded high plants with wide leaf and high yield, the group Ⅲ included dwarf plants with thin stem and flat bottom shape of leaf, which could provide the basis for cultivation identification and variety breeding of A.argyi germplasm resources.

Overexpression of NtAGPase small subunit gene increases leaf starch content and tobacco biomass / 生物工程学报

Production of biofuels such as ethanol from non-grain crops may contribute to alleviating the global energy crisis and reducing the potential threat to food security. Tobacco (Nicotiana tabacum) is a commercial crop with high biomass yield. Breeding of starch-rich tobacco plants may provide alternative raw materials for the production of fuel ethanol. We cloned the small subunit gene NtSSU of ADP-glucose pyrophosphorylase (NtAGPase), which controls starch biosynthesis in tobacco, and constructed a plant expression vector pCAMBIA1303-NtSSU. The NtSSU gene was overexpressed in tobacco upon Agrobacterium-mediated leaf disc transformation. Phenotypic analysis showed that overexpression of NtSSU gene promoted the accumulation of starch in tobacco leaves, and the content of starch in tobacco leaves increased from 17.5% to 41.7%. The growth rate and biomass yield of the transgenic tobacco with NtSSU gene were also significantly increased. The results revealed that overexpression of NtSSU gene could effectively redirect more photosynthesis carbon flux into starch biosynthesis pathway, which led to an increased biomass yield but did not generate negative effects on other agronomic traits. Therefore, NtSSU gene can be used as an excellent target gene in plant breeding to enrich starch accumulation in vegetative organs to develop new germplasm dedicated to fuel ethanol production.

Differences between male and female leaves of Schisandra sphenanthera: based on RNA-Seq / 中国中药杂志

Schisandra sphenanthera is dioecious and only the fruits of female plants can be used as medicine and food. It is of great significance for the cultivation and production of S. sphenanthera to explore the differences between male and female plants at the non-flowering stage and develop the identification markers at non-flowering or seedling stage. In this study, the transcriptome of male and female leaves of S. sphenanthera at the non-flowering stage was sequenced by Illumina high-throughput sequencing technology and analyzed based on bioinformatics. A total of 236 682 transcripts were assembled by Trinity software and 171 588 were chosen as unigenes. Finally, 1 525 differentially expressed genes(DEGs) were identified, with 458 up-regulated and 1 067 down-regulated in female lea-ves. The down-regulated genes mainly involve photosynthesis, photosynthesis-antenna protein, carbon fixation in photosynthetic or-ganisms, and other pathways. Real-time quantitative PCR(qPCR) identified two genes between male and female leaves and one of them was a HVA22-like gene related to floral organ development and abscisic acid(ABA). Enzyme linked immunosorbent assay(ELISA) was applied to determine the content of ABA, auxin, gibberellin, and zeatin riboside(ZR) in leaves of S. sphenanthera. The results showed that the content of ABA and ZR in male leaves was significantly higher than that in female leaves. The involvement of down-regulated genes in female leaves in the photosynthesis pathway and the significant differences in the content of endogenous hormones between male and female leaves lay a scientific basis for analyzing the factors affecting sex differentiation of S. sphenanthera.

Diversidad genética de materiales nativos de aguacate guatemalteco a través del marcador molecular AFLP / Genetic diversity of native Guatemalan avocado through AFLP molecular marker

El aguacate es un cultivo de consumo a nivel mundial, y según teorías recientes, se sugiere a la región de la Sierra Nevada, en California, como centro de origen y, a Guatemala, como uno de los principales centros de domesticación. Mediante caracterizaciones morfológicas se ha reportado una alta diversidad genética en el país, pero debido al comportamiento de polinización cruzada e hibridaciones interraciales, no se ha podido detallar el estado genético actual de la especie. Sin embargo, los marcadores moleculares son útiles para este tipo de estudios al enfocarse en las diferencias a nivel del ADN. Este estudio analizó la diversidad genética del aguacate nativo guatemalteco de siete poblaciones geográficas con el marcador molecular AFLP. Los datos de estructura poblacional mostraron un alto grado de diversidad a nivel de individuos (Ht = 0.1933, Hw = 0.1872) y baja diferenciación entre poblaciones (Hb = 0.0061). Los resultados sugieren una alta tasa de migración que influye directamente en el grado de mezcla genética de los materiales analizados. El bajo índice de estructura poblacional apunta a un alto flujo genético entre las poblaciones, por lo que la especie no presenta mayor riesgo ante la deriva genética, minimizándose el riesgo de pérdida de alelos por fijación. Se sugiere el resguardado del recurso fitogénetico total y no únicamente de materiales promisorios, evitando así el riesgo de erosión genética de la especie y garantizando la permanencia de la diversidad genética, la cual será la base de futuros programas de mejoramiento.

Avocado is one of the most widely consumed crops worldwide and according to new theories, the Sierra Nevada region in California is suggested as the center of origin and Guatemala as one of the main domestication cen-ters. Through morphological characterizations, a high genetic diversity has been reported in the country, but due to the behavior of cross pollination and interracial hybridizations, it has not been possible to detail the current genetic status of the species. Molecular markers are useful for this type of study by focusing on differences at DNA level. This study analyzed the genetic diversity of the native Guatemalan avocado from seven geographic populations with AFLP molecular marker. Population structure data showed a high degree of diversity at the individual level (Ht = 0.1933, Hw = 0.1872) and low differentiation between populations (Hb = 0.0061). The results suggest a high rate of migration that directly influences the degree of genetic mixing of the analyzed materials. The low index of population structure points to a high genetic flow between populations, so that the species does not present a greater risk due to genetic drift, minimizing the risk of loss of alleles due to fixation. The protection of the total genetic resource is suggested, and not only of promising materials, thus avoiding the risk of genetic erosion of the species and guaranteeing the permanence of genetic diversity, which will be the basis of future breeding programs.

A whole-transcriptome approach to evaluate reference genes for quantitative diurnal gene expression studies under natural field conditions in Tamarix ramosissima leaves

Background: Tamarix ramosissima is a desert forest tree species that is widely distributed in the drought-stricken areas to sustain the fragile ecosystem. Owing to its wide usage in the desert restoration of Asia, it can be used as an ecophysiological model plant. To obtain reliable and accurate results, a set of reference genes should be screened before gene expression. However, up to date, systematical evaluation of reference genes has not been conducted in T. ramosissima. Results: In this study, we used eigenvalues derived from principal component analysis to identify stable expressed genes from 72,035 unigenes from diurnal transcriptomes under natural field conditions. With combined criteria of read counts above 900 and CV of FPKM below 0.3, a total of 7385 unigenes could be qualified as candidate reference genes in T. ramosissima. By using three statistical algorithm packages, geNorm, NormFinder, and BestKeeper, the stabilities of these novel reference genes were further compared with a panel of traditional reference genes. The expression patterns of three aquaporins (AQPs) suggested that at least UBQ (high expression), EIF4A2 (low expression), and GAPDH (moderate expression) could be qualified as ideal reference genes in both RT-PCR and RNA-seq analysis of T. ramosissima. Conclusions: This work will not only facilitate future studies on gene expression and functional analysis of genetic resources of desert plants but also improve our understanding of the molecular regulation of water transport in this plant, which could provide a new clue to further investigate the drought adaptation mechanism of desert plant species under harsh environments.

Screening of melon genotypes for resistance to vegetable leafminer and your phenotypic correlations with colorimetry

ABSTRACT Melon is one of the most important vegetable crops in the world. With short cycle in a system of phased planting, phytosanitary control is compromised, and a great volume of agricultural chemicals is used to control vegetable leafminer. Genetic control is an ideal alternative to avoid the damage caused by this insect. Thus, the aim of this study was to evaluate Cucumis accessions in regard to resistance to leafminer and correlate the variables analyzed. Fifty-four accessions and four commercial hybrids of melon were tested. The study was divided into two experiments: with and with no choice. The following characteristics were evaluated: with choice, in field - subjective score based on the infestation and the number of mines per leaf; and with no choice, in cage - number of mines per leaf, chlorophyll content, and leaf colorimetry. The results showed variability among the accessions and some genotypes showed favorable results for resistance in both experiments. There was correlation between the two variables in the experiment in the field. The accessions CNPH 11-282, CNPH 06-1047, and CNPH 11-1077 are the most recommended for future breeding programs with aim on introgression of resistance to vegetable leafminer in melon.

Isolation of high-quality RNA from Platycladus orientalis and other Cupressaceae plants

Platycladus orientalis has a lifespan of several thousand years in China, making it a good plant in which to study aging at the molecular level, but this requires sufficient quantities of high-quality P. orientalis RNA. However, no appropriate methods have been reported for total RNA isolation from P. orientalis leaves. The TRIzol method did not extract RNA, while cetyltrimethylammonium bromide, sodium dodecyl sulfate-phenol, and plant RNAout kit (Tianz, Inc., China) protocols resulted in low yields of poor quality RNA. Isolating total RNA using the Spectrum™ Plant Total RNA Kit (Sigma-Aldrich, St. Louis, MO, USA) resulted in a high-quality product but a low yield. However, the two-step removal of polyphenols and polysaccharides in the improved plant RNAout kit protocol resulted in the isolation of RNA with a 28S:18S rRNA ratio of band intensities that was ~2:1, the A260/A280 absorbance ratio was 2.03, and the total RNA yield from P. orientalis leaves was high. This protocol was tested on different P. orientalis tissues of different ages and on leaves of five other Cupressaceae plants. The total RNAs were successfully used in complementary DNA synthesis for transcriptome sequencing and would be suitable to use in additional experiments. The results of this study will benefit future studies in Cupressaceae plants.

Characterization saprobic fungi on leaf litter of two species of trees in the Atlantic Forest, Brazil

Abstract We investigated the composition and structure of fungal communities associated with leaf litter generated by Clusia nemorosa and Vismia guianensis that belong to phylogenetically-related botanical families and exist together in a remnant of the Atlantic Forest in Bahia, Brazil. Samplings were conducted during wet (June 2011) and dry (January 2013) seasons in Serra da Jibóia. The fungi were isolated using particle filtration and the 1,832 isolates represented 92 taxa. The wet season yielded the largest number of isolates (1,141) and taxa (76) compared with the dry season (641 isolates and 37 taxa). The richness and diversity of fungal species associated with C. nemorosa (64 taxa, Simpson=0.95)were higher compared with those of V.guianensis (59 taxa, Simpson =0.90). Analysis of similarity (ANOSIM) revealed significant variations in the composition and community structure of fungi isolated from the two plants as a function of seasons. In contrast, nonmetric multidimensional scaling (NMDS) analysis show that the seasonality was an important influence on the distribution of fungal species. However, the populations of the saprobic fungal communities were dynamic, and several factors may influence such communities in the Atlantic Forest.

Chloroplast localization of Cry1Ac and Cry2A protein- an alternative way of insect control in cotton

BACKGROUND: Insects have developed resistance against Bt-transgenic plants. A multi-barrier defense system to weaken their resistance development is now necessary. One such approach is to use fusion protein genes to increase resistance in plants by introducing more Bt genes in combination. The locating the target protein at the point of insect attack will be more effective. It will not mean that the non-green parts of the plants are free of toxic proteins, but it will inflict more damage on the insects because they are at maximum activity in the green parts of plants. RESULTS: Successful cloning was achieved by the amplification of Cry2A, Cry1Ac, and a transit peptide. The appropriate polymerase chain reaction amplification and digested products confirmed that Cry1Ac and Cry2A were successfully cloned in the correct orientation. The appearance of a blue color in sections of infiltrated leaves after 72 hours confirmed the successful expression of the construct in the plant expression system. The overall transformation efficiency was calculated to be 0.7%. The amplification of Cry1Ac-Cry2A and Tp2 showed the successful integration of target genes into the genome of cotton plants. A maximum of 0.673 µg/g tissue of Cry1Ac and 0.568 µg/g tissue of Cry2A was observed in transgenic plants. We obtained 100% mortality in the target insect after 72 hours of feeding the 2nd instar larvae with transgenic plants. The appearance of a yellow color in transgenic cross sections, while absent in the control, through phase contrast microscopy indicated chloroplast localization of the target protein. CONCLUSION: Locating the target protein at the point of insect attack increases insect mortality when compared with that of other transgenic plants. The results of this study will also be of great value from a biosafety point of view.

An analysis of vascular system in the compound tendrilled afila leaf in Pisum sativum.

Recent work on the venation patterning and morphogenesis of leaf/leaflet has posed the question how different are these in tendrils, which are another type of vegetative lateral organ. Here, the venation patterns of leaflets, stipules and tendrils were compared in the model species, P. sativum. Unlike reticulated venation in leaflets and stipules, venation in tendrils comprised of one or more primary veins. A few secondaries were attached to a primary vein, mostly distally. Bilaterally symmetrical secondary veins were rare. The primary veins in tendrils were daughter strands from dichotomously divided mother veins in rachis, connected finally to vascular strands in stem. A tendril received primary vein from one or more mother strands. Some mother strands contributed primary veins to proximal, distal and terminal domain tendrils of af leaf. The tendrils shared the multi-primary vein character with stipules. Vein redundancy provided a mechanism for survival of tendril/leaf against injury to some of the veins/mother veins. The presence of aborted primary veins that did not reach apex, rows of cambium cells attached to primary vein(s) at apex, the pattern of attachment of primary veins to mother veins and cessation of vein growth in apical direction in aborted tendrils of af lld genotype indicated that the growth of primary veins and tendril was acropetal. Loss-of-function of AF extended the repression of TL and MFP genes on leaflet development from distal and apical domains to proximal domain of leaves in af mutants.

Manganese influx and its utilization efficiency in wheat.

Manganese deficiency in wheat has become an important nutritional disorder particularly in alkaline calcareous soils where rice-wheat rotation is followed. This experiment was aimed to study the mechanism of Mn efficiency during various developmental stages in six wheat cultivars grown at two Mn levels viz. 0 and 50 mg Mn kg-1soil (Mnapplied as MnSO4.H20) in pots. The Mn vegetative efficiency calculated on the basis of shoot dry weight at anthesis indicated HD 2967 and PBW 550 (bread wheat) as Mn efficient and durums as Mn inefficient. The efficient cultivars recorded highest values for influx, uptake, shoot dry weight, leaf area/plant, SPAD index, Fv/Fmratio and root length that explained their higher efficiencies whereas inefficiency of durum cultivars was attributed to their smaller roots and lower influx. Under Mn deficiency, PDW 314 and PDW 291 retained 68% and 64%, respectively, of total Mn uptake in vegetative parts (stem and leaves) and lowest in grains 7% and 5%, respectively, whereas PBW 550, BW 9178 and HD 2967 retained 29, 37 and 34% in vegetative parts, and 21, 17 and 15 % in grains, respectively at maturity. Higher utilization efficiency of efficient genotypes also indicated that increased Mn uptake with Mn supply produced more efficiently grains in efficient genotypes but vegetative parts in inefficient genotypes. Hence Mn efficiency of a cultivar could be explained by longer roots, higher uptake, influx and efficiency index during vegetative phase and higher grain yield and utilization efficiency during generative phase.

Qualidade de folhas e rendimento de óleo essencial em hortelã pimenta (Mentha x Piperita L. ) submetida ao processo de secagem em secador de leito fixo / Quality of leaves and essential oil yield of peppermint (Mentha x piperita L. ) submitted to the drying process in fixed-bed dryer

O uso de plantas medicinais e seus derivados para o tratamento de doenças é uma prática antiga e se percebe, atualmente, uma crescente procura por produtos naturais, incluindo medicamentos, produtos alimentícios, e cosméticos. Hortelã pimenta (Mentha x Piperita L), além de ser uma planta medicinal, pode ser utilizada para obtenção de aromatizantes, infusões, e temperos. O processo de secagem se faz necessário para aumentar o tempo de conservação e a vida útil do produto facilitando seu transporte, manuseio, e armazenamento. Para que os produtos derivados da hortelã pimenta tenham qualidade é necessário estudos sobre o processo de pré e de pós-colheita. Objetivou-se neste estudo identificar a temperatura de secagem, em duas velocidades de ar circulante, que minimize a degradação da cor das folhas e permita obter maior rendimento de óleo essencial. Folhas da hortelã foram colhidas manualmente no horário entre 7:15 e 8:00, e submetidas a secagem em duas velocidades do ar (0,3 e 0,5 m.s-1) e em cinco temperaturas (30, 40, 50, 60 e 70 °C). O material seco foi analisado quanto à cor utilizando-se colorímetro com escala do sistema CIELab baseado em coloração dentro dos padrões da Norma DIN 6174 (1979). A quantificação do óleo essencial foi realizada por hidrodestilação em aparelho Clevenger. Observou-se que temperaturas superiores a 50 °C reduzem o rendimento. A cor das folhas submetidas à secagem diferencia-se da cor das folhas frescas. De acordo com a Norma DIN 6174, a cor das folhas submetidas a secagem com temperatura até 40 °C são "Facilmente distinguíveis" e para as folhas submetidas à secagem a temperaturas superior a 50 °C, a diferenciação é "Muito grande". Conclui-se que para obter o máximo de rendimento do óleo essencial e o mínimo de degradação da cor, a secagem deve ser realizada a temperatura de até 50 ºC. A velocidade do ar de secagem, na faixa de 0,3 a 0,5 m.s-1, não afetou os parâmetros avaliados.

The use of medicinal plants and their derivatives for the treatment of diseases is an ancient practice. Currently, there is a growing demand for natural products, not only medicines, but also food and cosmetics. The peppermint (Mentha x piperita L.), in addition to being a medicinal plant, can be used for obtaining flavorings, spices and tea infusions. The drying process is necessary to increase the shelf life of the product and to facilitatg itr transport, handling and storage. For peppermint derivatives of sufficient quality, it is necessary studies on the pre- and post-harvest. The objective of this study is to identify the temperature and air velocity that minimizs the degradation of the color of the leaves with higher oil yield. PepperMint leaves were harvested manually from 7:15 to 8:00 a.m. and dried in trays in a completely randomized design in a 2 x 5 factorial design, being two air velocities (0.3 and 0.5 m.s-1) and five temperatures (30, 40, 50, 60 and 70 °C) with three replications. The dried material was analyzed for color using a colorimeter with the CIELab scale system based on a color within the DIN 6174 standards (1979). The quantification of the essential oil was performed by hydrodistillation in a Clevenger-type apparatus. The analyzes were performed in triplicate. Ws observed that the yield of essential oil of the dry leaves was highertwhan compared to the yield presented by the fresh leaves. This effect was attributed to the fact that the lower water content in the leaves enables the vapor stream generated in the extractor to promots a more effective drag of the volatile oilcompounds stored in the cells; however, a temperature exceeding 50 °C promotes a reduction in yield. The color of the leaves submitted to drying is different from the color of fresh leaves. According to the DIN 6174 standard, the color of the leaves subjected to drying at the temperature up to 40 °C is "easily distinguishable" and, for the leaves submitted to drying at temperatures higher than 50 °C, the differentiation is "too large". We conclude that to get the maximum yield of essential oil and minimal color degradation, drying should be carried out at a temperature of up to 50 °C. The rate of the drying processes in the rangeofrom 0.3 to 0.5 m.s-1 did not affect the parameters evaluated.

Anatomía foliar comparada y sistemática del clado-Trichocentrum con énfasis en Cohniella Asparagales: Orchidaceae / Comparative foliar anatomy and systematics of the Trichocentrum-clade with emphasis in Cohniella Asparagales: Orchidaceae

The genera Cohniella, Lophiarella, Lophiaris, and Trichocentrum are included in the Trichocentrum-clade. These genera are distributed from Florida and Northern Mexico to Southern Brazil and Northern Argentina, growing in tropical deciduous forests or tropical rain forests and thorn scrub forests to pine-oak forest, from sea level to 1 700m. The leaf anatomical structure of 23 members of the Trichocentrum-clade was explored as a source of taxonomic and phylogenetic characters. A total of 11 species of Cohniella, three species of Lophiarella, seven species of Lophiaris, two species of Trichocentrum, and other four species were included as outgroup. Anatomical characters were studied by cross sections and paradermic observations of the middle portion of fresh leaves. Although anatomical characters were fairly homogeneous throughout the clade, twelve vegetative anatomical, phylogenetically informative characters were selected and coded for an analysis that was performed using an exhaustive search implicit enumeration implemented through TNT. The strict consensus of 2 692 most parsimonious trees resulted in a poorly resolved polytomy, which however recovers the Trichocentrum-clade with a monophyletic, strongly supported Cohniella nested within it with unifacial leaves and the presence of cellular inclusions in the epidermis as synapomorphies. We concluded that the anatomy characters alone are insufficient to assess the relationships amongst the genera of the Trichocentrum-clade. However, the two synapomorphies recovered for Cohniella strongly support its monophyly when these are analyzed in conjunction with other data sources e.g., molecular and morphological characters.

El clado-Trichocentrum incluye los géneros Cohniella, Lophiarella, Lophiaris y Trichocentrum s.s. Estos géneros se distribuyen desde Florida y el Norte de México hasta el Sur de Brasil y Norte de Argentina, creciendo desde bosques caducifolios, bosques húmedos tropicales hasta matorrales espinosos y bosques de pino-encino, desde el nivel del mar hasta los 1 700m. En este estudio se exploró el valor taxonómico y filogenético de la estructura anatómica de las hojas de 23 especies del clado-Trichocentrum, repartidos en 11 especies de Cohniella, tres de Lophiarella, siete de Lophiaris y dos de Trichocentrum s.s., y de otras cuatro especies incluidas como grupo externo. Se realizaron secciones transversales y observaciones paradérmicas de la porción media de hojas frescas para el estudio de los caracteres anatómicos. Doce caracteres anatómico foliares fueron seleccionados y codificados para el análisis filogenético que se realizó mediante el uso de una búsqueda exhaustiva enumeración implícita con el programa TNT. El consenso estricto de 2 692 árboles más parsimoniosos dio lugar a una politomía que recupera dentro del clado-Trichocentrum a Cohniella como un clado monofilético fuertemente apoyado con sinapomorfías de las hojas unifaciales y la presencia de inclusiones celulares en la epidermis.

Analysis of gene expression in Kalanchoe daigremontiana leaves during plantlet formation under drought stress

Background: Kalanchoe daigremontiana is an attractive model system for the study of the molecular mechanisms of somatic embryogenesis and organogenesis competence due to its formation of plantlets with adventitious roots on the leaf margins that are derived from somatic embryos. The suppression subtractive hybridization technique was used to investigate gene expression during asexual reproduction. Leaves from plants subjected to drought stress provided the source of ‘Tester’ DNA, and leaves from plants grown under normal conditions provided the ‘Driver’ DNA for subtractive hybridization. Results: A total of 481 high quality ESTs were generated, which clustered into 390 unigenes. Of these unigenes, 132 grouped into 12 functional categories, suggesting that asexual reproduction is a complicated process involving a large number of genes. The expression characteristics of selected genes from the SSH library were determined by real-time PCR and were classified into five groups, suggesting that gene expression patterns during asexual reproduction are complex. Up-regulation of S-adenosylhomocysteine hydrolase suggested that a decrease in cytokinin levels promotes the initiation of plantlet formation. Many other genes, such as inorganic pyrophosphatase and glutamate decarboxylase, play important roles in gene regulation during asexual reproduction. Conclusion: Our results provide a framework and unified platform on which future research on asexual reproduction in K. daigremontiana can be based. This represents the first genome-wide study of asexual reproduction in K. daigremontiana.