Cloning and catalytic analysis of Isatis indigotica chalcone isomerase in vitro / 中国中药杂志

Chalcone isomerase is a key rate-limiting enzyme in the biosynthesis of flavonoids in higher plants, which determines the production of flavonoids in plants. In this study, RNA was extracted from different parts of Isatis indigotica and reverse-transcribed into cDNA. Specific primers with enzyme restriction sites were designed, and a chalcone isomerase gene was cloned from I. indigotica, named IiCHI. IiCHI was 756 bp in length, containing a complete open reading frame and encoding 251 amino acids. Homology analysis showed that IiCHI was closely related to CHI protein of Arabidopsis thaliana and had typical active sites of chalcone isomerase. Phylogenetic tree analysis showed that IiCHI was classified into type Ⅰ CHI clade. Recombinant prokaryotic expression vector pET28a-IiCHI was constructed and purified to obtain IiCHI recombinant protein. In vitro enzymatic analysis showed that the IiCHI protein could convert naringenin chalcone into naringenin, but could not catalyze the production of liquiritigenin by isoliquiritigenin. The results of real-time quantitative polymerase chain reaction(qPCR) showed that the expression level of IiCHI in the aboveground parts was higher than that in the underground parts and the expression level was the highest in the flowers of the aboveground parts, followed by leaves and stems, and no expression was observed in the roots and rhizomes of the underground parts. This study has confirmed the function of chalcone isomerase in I. indigotica and provided references for the biosynthesis of flavonoid components.

Genome-wide identification of SUN gene family in Fragaria vesca and stresses-response analysis / 生物工程学报

SUN gene is a group of key genes regulating plant growth and development. Here, SUN gene families of strawberry were identified from the genome of the diploid Fragaria vesca, and their physicochemical properties, genes structure, evolution and genes expression were also analyzed. Our results showed that there were thirty-one FvSUN genes in F. vesca and the FvSUNs encoded proteins were classified into seven groups, and the members in the same group showed high similarity in gene structures and conservative motifs. The electronic subcellular localization of FvSUNs was mainly in the nucleus. Collinearity analysis showed that the members of FvSUN gene family were mainly expanded by segmental duplication in F. vesca, and Arabidopsis and F. vesca shared twenty-three pairs of orthologous SUN genes. According to the expression pattern in different tissues shown by the transcriptome data of F. vesca, the FvSUNs gene can be divided into three types: (1) expressed in nearly all tissues, (2) hardly expressed in any tissues, and (3) expressed in special tissues. The gene expression pattern of FvSUNs was further verified by quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, the seedlings of F. vesca were treated by different abiotic stresses, and the expression level of 31 FvSUNs genes were assayed by qRT-PCR. The expression of most of the tested genes was induced by cold, high salt or drought stress. Our studies may facilitate revealing the biological function and molecular mechanism of SUN genes in strawberry.

Arabidopsis CK2 family gene CKB3 involved in abscisic acid signaling / Gene da família Arabidopsis CK2 CKB3 envolvido na sinalização de ácido abscísico

CKB3 is a regulatory (beta) subunit of CK2. In this study Arabidopsis thaliana homozygous T-DNA mutant ckb3 was studied to understand the role of CKB3 in abscisic acid (ABA) signaling. The results shown: CKB3 was expressed in all organs and the highest expression in the seeds, followed by the root. During seed germination and root growth the ckb3 mutant showed reduced sensitivity to ABA. The ckb3 mutant had more stomatal opening and increased proline accumulation and leaf water loss. The expression levels of number of genes in the ABA regulatory network had changed. This study demonstrates that CKB3 is an ABA signaling-related gene and may play a positive role in ABA signaling.

CKB3 é uma subunidade reguladora (beta) de CK2. Neste estudo, o mutante homozigoto ckb3 de Arabidopsis thaliana foi estudado para entender o papel da CKB3 na sinalização de ácido abscísico (ABA). Os resultados apresentados: CKB3 foi expresso em todos os órgãos e a maior expressão nas sementes, seguida pela raiz. Durante a germinação das sementes e o crescimento radicular, o mutante ckb3 mostrou sensibilidade reduzida ao ABA. O mutante ckb3 teve mais abertura estomática e aumento do acúmulo de prolina e perda de água nas folhas. Os níveis de expressão do número de genes na rede reguladora da ABA haviam mudado. Este estudo demonstra que CKB3 é um gene relacionado à sinalização ABA e pode desempenhar um papel positivo na sinalização ABA.

Cloning and functional analysis of AaHSFB1 and its promoter in Amorphophallus / 生物工程学报

To explore the function of a heat shock transcription factor gene (HSFB1) and its promoter in Amorphophallus, a 1 365 bp DNA sequence was obtained by homologous cloning from Amorphophallus albus. The gene expression level of AaHSFB1 determined by qRT-PCR indicated that AaHSFB1 gene is more sensitive to heat stress. The expression level of AaHSFB1 in roots increased followed by a decrease upon heat treatment, and the highest expression level was observed after heat treatment for 1 h. The expression level of AaHSFB1 in leaves reached the highest after heat treatment for 12 h. The expression level in bulbs did not change greatly during the heat treatment. Subcellular localization analysis showed that AaHSFB1 protein was localized in the nucleus. A 1 509 bp DNA sequence which contains the AaHSFB1 promoter was obtained by FPNI-PCR method. Bioinformatics analysis showed that the promoter contained heat stress response elements HSE and a plurality of cis-acting elements related to plant development and stress response. A prAaHSFB1::GUS fusion expression vector was constructed to further analyze the function of AaHSFB1 promoter. The expression vector was transformed into Arabidopsis thaliana by Agrobacterium tumefaciens-mediated method, and GUS staining analysis on transgenic plants after heat treatment was performed. The results showed that AaHSFB1 promoter had very high activity in the leaves. Therefore, we speculate that AaHSFB1 may play an important role in the stress resistance of A. albus, especially when encountering heat stress.

Research progress in regulation model in different types of plant trichome / 生物工程学报

Plant trichomes are special structures that originate from epidermal outgrowths. Trichomes play an important role in plant defense against pests and diseases, and possess economic and medicinal values. Study on molecular mechanism of plant trichomes will contribute to the molecular design breeding and genetic improvement of crops. In recent years, the regulation mechanism of trichome development has been basically clarified in the model plant Arabidopsis thaliana, while great progresses are also found in other plant species. In this review, we focus on the developmental regulation of trichome formation from gene and phytohormones levels in Arabidopsis and cotton (with unicellular trichomes), as well as in tomato and Artemisia annua (with multicellular trichomes). The research progress associated with trichomes is also introduced in other typical monocotyledons and dicotyledons. Finally, the research and application of plant trichomes are prospected.

Avaliação dos estudantes de enfermagem sobre a aprendizagem com a simulação clínica / Evaluación de los estudiantes de enfermería sobre el aprendizaje con la simulación clínica / Evaluation of nursing students about learning with clinical simulation

RESUMO Objetivo: descrever as contribuições da simulação clínica para aprendizagem de atributos cognitivos e procedimentais, por meio do debriefing, na perspectiva dos estudantes de enfermagem. Método: estudo descritivo exploratório. Participaram 20 estudantes de Graduação em Enfermagem de uma universidade do interior paulista. Na coleta de dados, realizada na etapa do debriefing, foi registrada a percepção do aluno sobre a simulação, aspectos positivos e o que poderia ser feito de forma diferente. Os relatos foram agrupados em categorias temáticas centrais, segundo referencial de análise de conteúdo de Bardin (2011), analisadas por meio de estatística descritiva. Resultados: identificada valorização da aprendizagem ativa, crítica e reflexiva (47,5%) em decorrência da aproximação à realidade assistencial (20,3%), manifestação dos sentimentos vivenciados durante a simulação (16,9%) e composição do cenário (15,3%). Conclusão: a simulação clínica seguida do debriefing favorece a compreensão da relação entre ação e resultados alcançados na aprendizagem. .

RESUMEN Objetivo: describir las contribuciones de simulación clínica para aprender atributos cognitivos y de procedimiento, a través de debriefing, desde la perspectiva de los estudiantes de enfermería. Método: estudio exploratorio descriptivo. 20 estudiantes participaron en el Pregrado en Enfermería de una universidad de São Paulo. Durante la recolección de datos, que se aplicó durante el debriefing, fue grabado en la percepción de los estudiantes de la simulación, los aspectos positivos y lo que podría hacerse de otra manera. Los informes de los estudiantes se agrupan de acuerdo a los temas centrales, según el referencial de análisis de contenido de Bardin (2011) y analizados mediante estadística descriptiva. Resultados: identificado la mejora de aprendizaje activo, crítico y reflexivo (47,5%) debido a la aproximación a la realidad en la atención de enfermería (20,3%), un resultado de la composición del escenario (16,9%), lo que favorece el desarrollo de sentimientos experimentados durante la simulación (15,3%). Conclusión: la simulación clínica seguida de debriefing favorece la comprensión de la relación entre la acción y los resultados obtenidos en el aprendizaje. .

ABSTRACT Objective: to describe the contributions of clinical simulation for learning cognitive and procedural attributes through debriefi ng, from the perspective of nursing students. Method: descriptive exploratory study. Twenty nursing undergraduate students from a university in the interior of the state of São Paulo participated in this study. Data collection was performed at the debriefi ng stage. Student’s perceptions about the simulation, positive aspects and what they could have done differently were registered. The students’ statements were grouped according to the central themes and the framework of Bardin’s content analysis (2011) and were analyzed using descriptive statistics. Results: enhancement of active, critical and refl ective learning (47.5%) was identifi ed due to the closeness to reality in nursing care (20.3%), manifestation of feelings experienced during the simulation (15.3%) and composition of the scenario (15.3%). Conclusion: the clinical simulation followed by debriefi ng promotes the understanding of the link between action and achievements in learning. .

Correlação e associação de renda e escolaridade com condições de saúde e nutrição em obesos graves / Correlation and association of income and educational level with health and nutritional conditions among the morbidly obese

O objetivo deste artigo é investigar relações entre renda e escolaridade com condições de saúde e nutrição em obesos graves. Estudo transversal ambulatorial com 79 pacientes de primeira consulta, com Índice de Massa Corporal (IMC) ≥ 35 kg/m2 e idade ≥ 20 anos. Coletaram-se dados: sociodemográficos, antropométricos, estilo de vida, exames bioquímicos e consumo alimentar. O IMC médio foi 48,3 ± 6,9 kg/m2. Observou-se correlação negativa significante de escolaridade com variáveis peso (r = -0,234) e IMC (r = -0,364) e de renda familiar per capita com consumo diário de vegetal A (r = -0,263). Após análise multivariada maior renda familiar per capita se associou à ausência de cardiopatia (RP: 0,51, IC95%: 0,32-0,81), maior consumo diário de vegetal A (RP: 1,79, IC95%: 1,16-2,75) e doces (RP: 3,12, IC95%: 1,21-8,04). Em obesos graves a maior renda familiar per capita se associou à ausência de cardiopatia e maior consumo de vegetais folhosos e doces. Já a escolaridade não se manteve associada às condições de saúde e nutrição.

This article seeks to investigate the relationship between income and educational level and health and nutritional conditions among the morbidly obese. A cross-sectional study was conducted with 79 patients at first appointment, with Body Mass Index (BMI) ≥ 35 kg/m2 and age ≥ 20 years. The following data was collected: demographic, socioeconomic, anthropometric, lifestyle, biochemical and food intake data. Average BMI was 48.3 ± 6.9 kg/m2. There was a significant negative correlation between education level and the variables of weight (r = -0.234) and BMI (r = -0.364) and per capita family income with daily consumption of leafy vegetables (r = -0.263). After multivariate analysis, higher per capita family income was associated with the absence of heart disease (PR: 0.51, CI95%: 0.32-0.81), higher daily consumption of leafy vegetables (PR: 1.79, CI95%: 1.16-2.75) and candy (PR: 3.12, CI95%: 1.21-8.04). In the morbidly obese, per capita household income was associated with absence of heart disease and higher consumption of leafy vegetables and candy. On the other hand, education level was not associated with health and nutrition conditions.

Effect of nickel chloride on Arabidopsis genomic DNA and methylation of 18S rDNA

Background In recent years, nickel (Ni) has been widely applied in industrial and agricultural production and has become a kind of environmental pollution. In this study, the effect of nickel chloride (NiCl2) with different concentrations on Arabidopsis genomic stability and DNA methylation has been demonstrated. The nucleolus variation and 18S rDNA methylation after NiCl2 treatment have been analyzed. Results The results are as follows: (1) The NiCl2 could result in heritable genomic methylation variations. The genomic DNA methylation variations have been detected by methylation-sensitive amplified polymorphism (MSAP) molecular markers, and the result showed that after NiCl2 treatment, there was methylation variation in T0 generation seedlings, and partial site changes maintained in T1 generation, which suggested that the effects of NiCl2 on DNA methylation could be heritable in offspring. (2) NiCl2 brought deformity and damage to nucleolar structure in Arabidopsis root tip cells, and the damage was positively correlated with the NiCl2 concentration. 3. In the nucleolus, there was an increased cytosine methylation in 18S rDNA. The plant nucleolus variation and 18S rDNA methylation may be used as an examination indicator for Ni pollution in soil or plant. Conclusions NiCl2 application caused variation of DNA methylation of the Arabidopsis genomic and offspring's. NiCl2 also resulted in nucleolar injury and deformity of root tip cells. The methylation rate of 18S rDNA also changed by adding NiCl2.

Molecular cloning and mRNA expression profile of Sucrose Transporter Gene BnSUT1C from Brassica napus L.

The genomic and cDNA sequences of BnSUT1C were isolated from B. napus. Combination of cDNA and genomic DNA sequences revealed that the BnSUT1C gene contained three exons and two introns. The cDNA encodes a protein of 513 amino acids with a calculated molecular mass of 54.7 kDa and an isoelectric point of 9.12. It exhibits typical features of sucrose transporter with 12 trans-membranes spanning domains. BnSUT1C showed highly homologous with AtSUC1 and AtSUC5. A histidine residue, which is conserved across all functional sucrose transporter proteins in higher plants, is located at position 66 of the BnSUT1C. Two putative pollen-specific cis-elements, AGAAA and GTGA motifs, are located in 5′-upstream of BnSUT1C. The spatial and temporal expression patterns carried out by semi-quantitative RT-PCR and Real-Time PCR, which indicated that BnSUT1C predominantly expressed in later developmental stages of anther, as tapetal cells began to shrink and collapse. BnSUT1C could mediate the uptake of sucrose in the pollen and retrieval of tapetal degenerated products during pollen maturation.

Effect of cryopreservation on the efficiency of exogenous gene, genetic transformation and expression level of Arabidopsis thaliana

Background: Cryopreservation refers to the storage of a living organism at ultra-low-temperature for long-term preservation of plant germplasm. The effect of cryopreservation on the efficiency of exogenous gene genetic transformation and expression level were studied herein. In this work, transgenic Arabidopsis thaliana were successfully conserved in vitro by cryopreservation methods. Results: The effects of osmotic stress due to cryoprotectants during pretreatment and of storage at -196ºC on the stability, the efficiency of genetic transformation and the expression level of exogenous gene were analyzed in Arabidopsis. The results showed that there had not any significant increasing in the efficiency of genetic transformation after cryopreservation, and our observation was not in agreement with earlier reports. Transgenic Arabidopsis lines over-expressing ATOST1 gene were used for the real-time PCR analysis, and the result indicated that the expression of the ATOST1 gene was up-regulated about 2.4-fold in the transgenic seedlings tissues retrieved from cryopreservation than those non-cryopreserved counterparts. Conclusions： Cryopreservation could improve the expression of exogenous gene, however, could not promote the genetic transformation obviously.

Chemical Genomics in Plant Biology.

Chemical genomics is a newly emerged and rapidly progressing field in biology, where small chemical molecules bind specifically and reversibly to protein(s) to modulate their function(s), leading to the delineation and subsequent unravelling of biological processes. This approach overcomes problems like lethality and redundancy of classical genetics. Armed with the powerful techniques of combinatorial synthesis, high-throughput screening and target discovery chemical genomics expands its scope to diverse areas in biology. The well-established genetic system of Arabidopsis model allows chemical genomics to enter into the realm of plant biology exploring signaling pathways of growth regulators, endomembrane signaling cascades, plant defense mechanisms and many more events.

A comparative analysis of green fluorescent protein and beta-glucuronidase protein-encoding genes as a reporter system for studying the temporal expression profiles of promoters.

The assessment of activity of promoters has been greatly facilitated by the use of reporter genes. However, the activity as assessed by reporter gene is a reflection of not only promoter strength, but also that of the stability of the mRNA and the protein encoded by the reporter gene. While a stable reporter gene product is an advantage in analysing activities of weak promoters, it becomes a major limitation for understanding temporal expression patterns of a promoter, as the reporter product persists even after the activity of the promoter ceases. In the present study we undertook a comparative analysis of two reporter genes, beta-glucuronidase (gus) and green fluorescent protein (sgfp), for studying the temporal expression pattern of tapetum-specific promoters A9 (Arabidopsis thaliana) and TA29 (Nicotiana tabacum). The activity of A9 and TA29 promoters as assessed by transcript profiles of the reporter genes (gus or sgfp ) remained the same irrespective of the reporter gene used. However, while the deduced promoter activity using gus was extended temporally beyond the actual activity of the promoter, sgfp as recorded through its fluorescence correlated better with the transcription profile. Our results thus demonstrate that sgfp is a better reporter gene compared to gus for assessment of temporal activity of promoters. Although several earlier reports have commented on the possible errors in deducing temporal activities of promoters using GUS as a reporter protein, we experimentally demonstrate the advantage of using reporter genes such as gfp for analysis of temporal expression patterns.

A highly efficient miPCR method for isolating FSTs from transgenic Arabidopsis thaliana plants.

The exact localization of an insertion in the genome of transgenic plants obtained by Agrobacterium-mediated transformation is an integral part of most experiments aimed at studying these types of mutants. There are several methods for isolating unknown nucleotide sequences of genomic DNA which flank the borders of T-DNA integrated in the genome of plants. However, all the methods based on PCR have limitations which in some cases do not permit the desired objective to be achieved. We have developed a new technique for isolating flanking sequence tags (FSTs) via modified inverse PCR. This method is highly efficient and simple, but also retains the advantages of previously well-documented approaches.

Caracterização funcional do gene maBMY que codifica para uma `BETA´-amilase endereçada a plastídeos e expressa durante o amadurecimento da banana / Functional characterization of maBMY gene that encodes a `BETA´-amylase targeted to plastids and expressed during banana ripening

O amadurecimento dos frutos é um processo caracterizado pela ocorrência de diversas alterações bioquímicas que ocorrem em um curto intervalo de tempo e que são importantes para a qualidade desses alimentos. Na banana uma das características mais importantes é o adoçamento do fruto, que ocorre como resultado da degradação do amido e acúmulo de sacarose. Resultados do nosso grupo apontam a ´BETA` amilase como uma enzima importante no processo de mobilização do amido, o que também é visto em estudos recentes utilizando Arabidopsis thaliana como modelo, os quais mostram que a principal via de degradação do amido transitório presente nas folhas ocorre pela ação da ´BETA`-amilase. Entretanto, em bananas, faltam evidências quanto à funcionalidade de um gene de ´BETA`amilase, parcialmente isolado da polpa do fruto, e que é expresso durante o amadurecimento e que parece ser modulado por hormônios vegetais. Em vista disso, esse trabalho objetivou realizar a caracterização funcional desse gene, a qual permitiu constatar que esse gene codifica, de fato, para uma proteína capaz de ser endereçada aos cloroplastos. Também foi observado que o promotor desse gene contém motivos regulatórios para os mesmos hormônios previamente relacionados com a modulação da expressão desse gene em bananas. Essas novas evidências reforçam a idéia de que o produto desse gene de ´BETA`amilase tem um importante papel no processo de degradação do amido durante o amadurecimento da banana...

Amplification of genome-integrated BeYDV replicons by transient expression of Rep in Arabidopsis thaliana

Bean yellow dwarf geminivirus (BeYDV) has been used as a potential vector to improve foreign gene expression, specifically, to achieve higher yields of vaccine proteins in plants. Previously, we have shown that when the BeYDV replication initiator protein Rep was provided in trans, replication and gene expression of GUS were enhanced enormously from a BeYDV expression vector in a transient assay system. In this paper, transgenic lines of Arabidopsis (cv. Columbia) were generated harboring the BeYDV cis-acting elements required for replication. Constructs encoding BeYDV Rep or intronless Rep open reading frames (ORFs) were transiently introduced into transgenic plants via Agrobacterium-mediated infiltration in order to examine the relative levels of replication and expression of the genome-integrated GUS reporter gene. This study shows that expression of Rep protein was regulated in trans from a separate cassette which enabled the rescue, replication and enhancement of the genome-integrated GUS gene in transgenic Arabidopsis. We conclude that Rep expression can be effectively controlled in Arabidopsis plants, and that regulation of Rep expression can result in the amplification of a genome-integrated foreign gene by circumventing the negative effects of gene silencing.

Unique nucleotide polymorphism of ankyrin gene cluster in Arabidopsis.

The ankyrin (ANK) gene cluster is a part of a multigene family encoding ANK transmembrane proteins in Arabidopsis thaliana, and plays an important role in protein-protein interactions and in signal pathways. In contrast to other regions of a genome, the ANK gene cluster exhibits an extremely high level of DNA polymorphism in an approximately 5-kb region, without apparent decay. Phylogenetic analysis detects two clear, deeply differentiated haplotypes (dimorphism). The divergence between haplotypes of accession Col-0 and Ler-0 (Hap-C and Hap-L) is estimated to be 10.7%, approximately equal to the 10.5% average divergence between A. thaliana and A. lyrata. Sequence comparisons for the ANK gene cluster homologues in Col-0 indicate that the members evolve independently, and that the similarity among paralogues is lower than between alleles. Very little intralocus recombination or gene conversion is detected in ANK regions. All these characteristics of the ANK gene cluster are consistent with a tandem gene duplication and birth-and-death process. The possible mechanisms for and implications of this elevated nucleotide variation are also discussed, including the suggestion of balancing selection.

The importance of Arabidopsis seed mutants in the elucidation of the molecular basis of Endosperm Balance Number in tuber-bearing Solanum species

The Endosperm Balance Number (EBN) is an important concept for potato breeding and has evolutionary importance in tuber-bearing Solanum species. The EBN is part of the post-zygotic hybridization barriers in the group and represents a reproductive isolating mechanism. Few genes have been proposed to be involved in its genetic control; until now, however, neither specific genes nor its molecular basis have been well established. Histological observations of embryo and endosperm development in inter-EBN crosses in tuber-bearing Solanum revealed phenotypes similar to those recently described in Arabidopsis seed mutants. The common feature between them is that the endosperm nuclei become greatly enlarged and that embryos are arrested at the globular stage. The proteins encoded by the Arabidopsis TITAN genes are related to chromosome dynamics and cell division. Based on the sequence of titan mutants, genes in potato species related to cell cycle and microtubule assembly were isolated. In this article a perspective model is proposed to explore the utility of Arabidopsis mutants associated with cell cycle control as a tool to elucidate the molecular basis of EBN in potato. Further research focused on the expression pattern of these genes in intra- and inter-EBN crosses in potato species will be performed.

The reactive oxygen species network pathways:an essential prerequisite for perception of pathogen attack and the acquired disease resistance in plants.

Availability of complete Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa) genome sequences, together with molecular recourses of functional genomics and proteomics have revolutionized our understanding of reactive oxygen species (ROS) signalling network mediating disease resistance in plants. So far, ROS have been associated with aging, cellular and molecular alteration in animal and plant cells. Recently,concluding evidences suggest that ROS network is essential to induce disease resistance and even to mediate resistance to multiple stresses in plants. ROS are obligatory by-products emerging as a result of normal metabolic reactions. They have the potential to be both beneficial and harmful to cellular metabolism. Their dual effects on metabolic reactions are dosage specific. In this review we focus our attention on cellular ROS level to trigger beneficial effects on plant cells responding to pathogen attack. By exploring the research related contributions coupled with data of targeted gene disruption, and RNA interference approaches, we show here that ROS are ubiquitous molecules of redox-pathways that play a crucial role in plant defence mechanism. The molecular prerequisites of ROS network to activate plant defence system in response to pathogen infections are here underlined. Bioinformatic tools are now available to scientists for high throughput analysis of cellular metabolisms. These tools are used to illustrate crucial ROS-related genes that are involved in the defence mechanism of plants. The review describes also the emerging findings of ROS network pathways to modulate multiple stress resistance in plants.

Arabidopsis thaliana: A model host plant to study plant-pathogen interaction using Chilean field isolates of Botrytis cinerea

One of the fungal pathogens that causes more agriculture damage is Botrytis cinerea. Botrytis is a constant threat to crops because the fungus infects a wide range of host species, both native and cultivated. Furthermore, Botrytis persists on plant debris in and on the soil. Some of the most serious diseases caused by Botrytis include gray mold on vegetables and fruits, such as grapes and strawberries. Botrytis also causes secondary soft rot of fruits and vegetables during storage, transit and at the market. In many plant-pathogen interactions, resistance often is associated with the deposition of callose, accumulation of autofluorescent compounds, the synthesis and accumulation of salicylic acid as well as pathogenesis-related proteins. Arabidopsis thaliana has been used as a plant model to study plant-pathogen interaction. The genome of Arabidopsis has been completely sequenced and this plant serves as a good genetic and molecular model. In this study, we demonstrate that Chilean field isolates infect Arabidopsis thaliana and that Arabidopsis subsequently activates several defense response mechanisms associated with a hypersensitive response. Furthermore, we propose that Arabidopsis may be used as a model host species to analyze the diversity associated with infectivity among populations of Botrytis cinerea field isolates...

Analysis of the SHP2 enhancer for the use of tissue specific activation tagging in Arabidopsis thaliana

Activation tagging is a powerful tool to identify new mutants and to obtain information about possible biological functions of the overexpressed genes. The quadruple cauliflower mosaic virus (CaMV) 35S enhancer fragment is a strong enhancer, which is most commonly used for this purpose. However, the constitutive nature of this enhancer may generate lethal mutations or aberrations in different plant organs by the same overexpressed gene. A tissue-specific activation tagging approach may overcome these drawbacks and may also lead more efficiently to the desired phenotype. For this reason the SHATTERPROOF2 (SHP2) promoter fragment was analysed for enhancer activity. The SHP2 gene is involved in dehiscence zone development and expressed during silique development. The aim of the experiments described here was to identify a dehiscence zone specific enhancer that could be used for tissue-specific activation tagging. The chosen SHP2 enhancer fragment was found to be expressed predominantly in the dehiscence zone and showed enhancer activity as well as ectopic expression activity. This activity was not influenced by its orientation towards the promoter and it was still functional at the largest tested distance of 2.0 kb. Based on these results, the SHP2 enhancer fragment can potentially be used in a tissue-specific activation tagging approach to identify new Arabidopsis mutants with an altered dehiscence zone formation.