Sugarcane genes associated with sucrose content

<p>Abstract</p> <p>Background -</p> <p>Sucrose content is a highly desirable trait in sugarcane as the worldwide demand for cost-effective biofuels surges. Sugarcane cultivars differ in their capacity to accumulate sucrose and breeding programs routinely perform crosses to identify genotypes able to produce more sucrose. Sucrose content in the mature internodes reach around 20% of the culms dry weight. Genotypes in the populations reflect their genetic program and may display contrasting growth, development, and physiology, all of which affect carbohydrate metabolism. Few studies have profiled gene expression related to sugarcane's sugar content. The identification of signal transduction components and transcription factors that might regulate sugar accumulation is highly desirable if we are to improve this characteristic of sugarcane plants.</p> <p>Results -</p> <p>We have evaluated thirty genotypes that have different Brix (sugar) levels and identified genes differentially expressed in internodes using cDNA microarrays. These genes were compared to existing gene expression data for sugarcane plants subjected to diverse stress and hormone treatments. The comparisons revealed a strong overlap between the drought and sucrose-content datasets and a limited overlap with ABA signaling. Genes associated with sucrose content were extensively validated by qRT-PCR, which highlighted several protein kinases and transcription factors that are likely to be regulators of sucrose accumulation. The data also indicate that aquaporins, as well as lignin biosynthesis and cell wall metabolism genes, are strongly related to sucrose accumulation. Moreover, sucrose-associated genes were shown to be directly responsive to short term sucrose stimuli, confirming their role in sugar-related pathways.</p> <p>Conclusion -</p> <p>Gene expression analysis of sugarcane populations contrasting for sucrose content indicated a possible overlap with drought and cell wall metabolism processes and suggested signaling and transcriptional regulators to be used as molecular markers in breeding programs. Transgenic research is necessary to further clarify the role of the genes and define targets useful for sugarcane improvement programs based on transgenic plants.</p

Combinatorial regulation modules on GmSBP2 promoter: a distal cis-regulatory domain confines the SBP2 promoter activity to the vascular tissue in vegetative organs

The Glycine max sucrose binding protein (GmSBP2) promoter directs phloem-specific expression of reporter genes in transgenic tobacco. Here, we identified cis-regulatory domains (CRD) that contribute with positive and negative regulation for the tissue-specific pattern of the GmSPB2 promoter. Negative regulatory elements in the distal CRD-A (−2000 to −700) sequences suppressed expression from the GmSBP2 promoter in tissues other than seed tissues and vascular tissues of vegetative organs. Deletion of this region relieved repression resulting in a constitutive promoter highly active in all tissues analyzed. Further deletions from the strong constitutive −700GmSBP2 promoter delimited several intercalating enhancer-like and repressing domains that function in a context-dependent manner. Histochemical examination revealed that the CRD-C (−445 to −367) harbors both negative and positive elements. This region abolished promoter expression in roots and in all tissues of stems except for the inner phloem. In contrast, it restores root meristem expression when fused to the −132pSBP2-GUS construct, which contains root meristem expression-repressing determinants mapped to the 44-bp CRD-G (−136 to −92). Thus, the GmSBP2 promoter is functionally organized into a proximal region with the combinatorial modular configuration of plant promoters and a distal domain, which restricts gene expression to the vascular tissues in vegetative organs

The soybean sucrose binding protein gene family: genomic organization, gene copy number and tissue‐specific expression of the SBP2 promoter

The sucrose binding protein (SBP) from soybean has been implicated as an important component of the sucrose uptake system. Two SBP genomic clones, gsS641.1 and gsS641.2, which correspond to allelic forms of the GmSBP2/S64 gene, have been isolated and characterized. As a member of the seed storage protein superfamily, it has been shown that the SBP gene structure is similar to vicilin genes with intron/exon boundaries at conserved positions. Fluores cence in situ hybridization (FISH) suggested that the soybean SBP gene family is represented by at least two non‐allelic genes corresponding to the previously isolated GmSBP1 and GmSBP2/S64 cDNAs. These two cDNAs share extensive sequence similarity but are located at different loci in the soybean genome. To investigate transcriptional activation of the GmSBP2 gene, 2 kb 5′‐flanking sequences of gsS641.1 and gsS641.2 were fused to the β‐glucuronidase (GUS) reporter gene and to the green fluorescent protein (GFP) reporter gene and inde pendently introduced into Nicotiana tabacum by Agrobacterium tumefaciens‐mediated transformation. The SBP2 promoter directed expression of both GUS and GFP reporter genes with high specificity to the phloem of leaves, stems and roots. Thus, the overall pattern of SBP–GUS or SBP–GFP expression is consistent with the involvement of SBP in sucrose translocation‐dependent physiological processes

Conservação da maçã (Malus domestica Borkh.) cv. Braeburn Storage in controlled atmosphere of 'Braeburn' (Malus domestica, Borkh.) apples

O experimento foi desenvolvido com o objetivo de avaliar o efeito da temperatura e de diferentes regimes de armazenamento em atmosfera controlada (AC) sobre as qualidades físico-químicas e ocorrência de distúrbios fisiológicos da maçã cv. Braeburn. O delineamento experimental foi o inteiramente casualizado, com duas repetições e a unidade experimental composta por 40 frutos. Os frutos foram armazenados nas seguintes condições de AC: na temperatura de 1ºC com 1,5kPaO2/ 4,0kPaCO2, 1,5kPaO2/3,0kPaCO2, 1,0kPaO2/1,0kPaCO2, 1,0kPaO2/2,0kPaCO2, 1,0kPaO2/3,0kPaCO2 e em armazenamento refrigerado (AR) e na temperatura de 0ºC com 1,0kPaO2/3,0kPaCO2 e em AR. A umidade relativa foi mantida a 96%. As análises laboratoriais foram realizadas aos oito meses de armazenamento, na abertura das câmaras e após sete dias de exposição à temperatura ambiente (±31ºC). Logo após a retirada dos frutos da câmara, não se observaram diferenças significativas na firmeza de polpa, acidez titulável e teor de sólidos solúveis totais (SST) entre as condições de AC. Contudo, após sete dias de exposição à temperatura ambiente, o tratamento com 1,0kPaO2/3,0kPaCO2, na temperatura de 0ºC, manteve a firmeza de polpa, acidez titulável e o teor de SST mais elevados, além de não exibir degenerescência senescente. O armazenamento em AC com 4,0kPa de CO2 e o armazenamento refrigerado causaram degenerescência senescente. Já a degenerescência com cortiça foi induzida pelo uso de 3,0 e 4,0kPa de CO2, associado com 1,5kPa de O2. As podridões foram significativamente maiores em AR do que em AC, sendo mais freqüente em baixa concentração de CO2 (1kPa). A incidência de rachaduras e escaldadura foi insignificante e não foi associada a nenhuma condição de armazenamento. No armazenamento refrigerado, os frutos apresentaram qualidade insatisfatória para a comercialização e consumo após oito meses de armazenamento.<br>The experiment was carried out with the objective of evaluating the effect of the temperature and of different controlled atmosphere (CA) storage regimes on the fruit qualities, and occurrence of physiological disorders of 'Braeburn' apples. The experimental design was the completely randomized with two replication. Fruits were stored in cold storage at 0 and 1ºC and in the following CA conditions: at temperature of 1ºC with 1,5kPaO2/4,0KkPaCO2, 1,5kPaO2/3,0kPaCO2, 1,0kPaO2/ 1,0kPaCO2, 1,0kPaO2/2,0kPaCO2, 1,0kPaO2/3,0kPaCO2 and at temperature of 0ºC with 1,0kPaO2/3,0kPaCO2. The relative humidity was maintained around 96%. The evaluation was done after eight months of storage, at the opening of the chambers and after seven days shelf life (31ºC). At chambers openning, there was no significant difference in the flesh firmness, titratable acidity and total soluble solids (TSS) among the CA conditions. However, after seven days in shelf life, the treatment with 1,0kPaO2/3,0kPaCO2 in the temperature of 0ºC maintained higher flesh firmness, titratable acidity and TSS, and did not exhibiting flesh breakdown. The CA storage, with 4,0kPa CO2 and cold storage caused flesh breakdown. Already the cork breakdown, was induced by 3,0 and 4,0kPa of CO2 associated with 1,5kPa of O2. The occurrence of rot was significantly higher in cold storage than in CA and more frequent al low CO2 (1kPa). The incidence of mealiness and scald could not be associated with any storage condition. Cold storage fruits presented unsatisfactory quality for marketing and consumption after 8 months of storage

Influência da época de colheita e do armazenamento em atmosfera controlada na qualidade da maçã 'Braeburn' Influence of harvest maturity and controlled atmosphere conditions on the quality of 'Braeburn' apple

Foi avaliado o efeito da época de colheita e das condições de armazenamento em atmosfera controlada sobre a firmeza da polpa, acidez titulável, ºBrix e, principalmente, sobre a ocorrência de degenerescência da polpa em maçãs (Malus domestica cv. Braeburn). Os tratamentos consistiram na combinação da data de colheita (27/3/1997 e 9/4/1997) com condição de armazenamento (temperatura de 0,5°C com: 1 kPa de O2/4,0 kPa de CO2; 1 kPa de O2/3,0 kPa de CO2; 1 kPa de O2/2,0 kPa de CO2; 21 kPa de O2/0,0 kPa de CO2, e temperatura de -0,5°C com: 1kPa de O2/3,0 kPa de CO2; 1 kPa de O2/2,0 kPa de CO2). Após oito meses de armazenamento, não foi observada suscetibilidade da maçã cv. Braeburn à baixa temperatura de armazenamento (-0,5ºC) e os frutos armazenados em ambiente refrigerado apresentaram baixa qualidade para o consumo. As condições de atmosfera controlada de 1 kPa de O2 associadas com 2 e 3 kPa de CO2 e a -0,5ºC apresentaram menor incidência de podridões, rachaduras e degenerescência senescente. Os frutos colhidos tardiamente, em 9/4/1997, apresentaram maior incidência de podridões, polpa farinhenta, degenerescência com cortiça e rachaduras. Nos parâmetros firmeza da polpa, acidez titulável e teor de sólidos solúveis totais não se observaram diferenças entre as condições de atmosfera controlada, após sete dias de exposição à temperatura de 25ºC.<br>This work was carried out to evaluate the effect of harvest maturity and controlled atmosphere on the quality and internal breakdown incidence in apples (Malus domestica) cv. Braeburn. The treatments consisted in the combination of harvest maturity (March 27, 1997 and April 9, 1997) with storage conditions (0.5°C with: 1 kPa O2/4 kPa CO2; 1 kPa O2/3 kPa CO2; 1 kPa O2/2 kPa CO2; 21 kPa O2/0 kPa CO2-cold storage and; -0.5°C with: 1 kPa O2/3 kPa CO2; 1 kPa O2/2 kPa CO2). After eight months of storage, there was no low temperature injury on fruits stored at -0.5ºC, and the cold storage fruits presented low quality for consumption. Under controlled atmosphere conditions of 1 kPa O2 combined with 2 and 3 kPa CO2 in -0.5ºC, the fruits presented lower rot, fruit cracking and internal breakdown incidence. Late harvested fruits (April 9, 1997) presented higher rot, mealy pulps, cork breakdown and craked fruits incidence. For flesh firmness, titratable acidity and TSS there was no significant difference among controlled atmosphere conditions after seven days in shelf life

Profili attuali della soggezione del giudice alla \u201clegge\u201d e della vincolativit\ue0 del precedente

In una fase di rilevante difficolt\ue0 per il paradigma tradizionale del principio di legalit\ue0, si \ue8 discusso ampiamente del ruolo dell\u2019interpretazione in relazione all\u2019equilibrio di poteri definito dalla Costituzione. Vero \ue8 che il giudice \ue8 soggetto soltanto alla legge. Tuttavia, \ue8 divenuto impossibile prevedere la effettiva qualificazione giuridica di un fatto se non avendo a mente l\u2019orientamento ermeneutico seguito dalla giurisprudenza di legittimit\ue0. Occorre, perci\uf2, indagare l\u2019assetto attuale della funzione nomofilattica giacch\ue9 solo la sinergia tra legislatore e giudice promette di scongiurare gravi violazioni delle garanzie sovranazionali. Al riguardo, la \u201ccultura del precedente\u201d offre indicazioni di metodo che potrebbero rivelarsi utili, persino in un modello di civil law, quale chiave di lettura delle recenti riforme legislative.While the traditional idea of legality faces a significant crisis, the debate upon interconnections among judicial interpretation and balance of constitutional powers acquires relevance. On one hand, the judge is subject to the law. On the other hand, judicial interpretation became essential in order to assess criminal liability. Thus, it is necessary to deeper examine the function exerted by the Italian Supreme Court: the equilibrium between legislator and judge is the one able to ensure supranational guarantees. In this frame, the \u2018stare decisis doctrine\u2019 could provide the civil law paradigm with useful indications to understand recent legislative reforms.En un periodo de creciente dificultad para el paradigma tradicional del principio de legalidad, se ha discutido ampliamente sobre el rol de la interpretaci\uf3n judicial en relaci\uf3n al equilibrio de poderes definido por la Constituci\uf3n. Por una parte, es cierto que el juez se encuentra sujeto solamente a la ley. Sin embargo, la praxis demuestra que es casi imposible prever la efectiva calificaci\uf3n jur\ueddica de un hecho si no se tiene en consideraci\uf3n el orientamiento hermen\ue9utico seguido por la jurisprudencia. Por lo tanto, es necesario investigar con mayor profundidad la estructura actual de la funci\uf3n nomofil\ue1ctica, toda vez que solo la sinergia entre el legislador y el juez puede asegurar el cumplimiento de las garant\uedas supranacionales. Al respecto, la \u201ccultura del precedente\u201d podr\ueda proveer, al sistema de civil law, \ufatiles indicaciones para entender las recientes reformas legislativas