Rice is a poor source of micronutrients such as iron and zinc. To help clarify the molecular mechanisms that regulate metal mobilization from leaves to developing seeds, we conducted suppression subtractive hybridization analysis in flag leaves of two rice cultivars. Flag leaves are the major source of remobilized metals for developing seeds. We isolated 78 sequences up-regulated in flag leaves at the grain filling stage relative to the panicle exertion stage. Differential expression of selected genes (encoding 7 transport proteins, the OsNAS3 enzyme and the OsNAC5 transcription factor) was confirmed by quantitative RT-PCR. We show that OsNAC5 expression is up-regulated by natural (aging) and induced senescence processes (dark, ABA application, high salinity, cold and Fe-deficiency) and its expression is not affected in the presence of 6-benzylaminopurine (a senescence inhibitor) under dark-induced senescence. Salt induction of OsNAC5 expression is abolished by nicotinamide, an inhibitor of ABA effects. This result and the presence of cis-acting elements in the promoter region of the OsNAC5 gene suggest an ABA-dependent regulation. Using four different rice cultivars, we show that OsNAC5 up-regulation is higher and earlier in flag leaves and panicles of IR75862 plants, which have higher seed concentrations of Fe, Zn and protein. We suggest that OsNAC5 is a novel senescence-associated ABA-dependent NAC transcription factor and its function could be related to Fe, Zn and amino acids remobilization from green tissues to seeds.

No abstract

Iron deficiency is among the most common nutritional disorders in plants. Low iron supply causes decreased root growth and even plant death. However, there are no reports about the specific pathways that lead Fe-deficient roots to senescence and death. To investigate the molecular mechanisms that regulate rice roots response to Fe-deficiency, rice seedlings were grown for 3, 6 and 9 days in the presence or absence of Fe. Sequences of 28 induced genes in rice roots under Fe-deficiency were identified by representational difference analysis (RDA). About 40% of these sequences have been previously reported as senescence-related. Differential expression of selected genes was confirmed by semi-quantitative RT-PCR analysis. Classical senescence-related sequences, such as MYB and WRKY transcription factors, cysteine protease, ubiquitin-conjugating enzyme, lipid transfer protein, fatty acid hydroxylase, beta-glucosidase and cytochrome P450 oxydoreductase were identified. Fe-deficiency also resulted in decreased dry weight, increased lipid peroxidation (detected by TBA and histochemical methods) as well as evident membrane damage in Fe-deficient roots. Taken together, the results indicate that Fe-deficiency in roots is linked to typical senescence pathways, associated with lipid peroxidation.

In this paper we report meiotic behaviour in 28 accessions of the tetraploid (2n = 4x = 104 or 112) Leucaena confertiflora, L. diversifolia, L. involucrata, L. leucocephala, L. x spontanea and the diploid (2n = 2x = 52 or 56) L. shannonii and L. macrophylla. We compare and discuss our data with that on literature about polyploidy in the genus. Despite the general predominance of bivalent formation, quadrivalents and other associations were found in all the taxa analysed. In the diploid species. multiple associations were found in up to 62% of the cells in L. shannonii and 97.6% in L. macrophylla. In the tetraploid taxa irregularities such as univalents, trivalents and other multivalents were observed in varying proportions, up to 55% in L. involucrata. Mean meiotic indexes per accession in the diploids and tetraploids were over or near 90%, but pollen fertility varied from 54.2% to 87.3%. The rather frequent presence of quadrivalents in the diploid species supports a paleopolyploid origin. For the tetraploid taxa, the presence of quadrivalents reflect chromosomal homology due to polyploid origin. Even if an autotetraploid origin cannot be ruled out by cytological data alone, considering other existing evidence, it is probable that L. confertiflora, L. pallida, L. leucocephala and L. involucrata are segmental allopolyploids. However, an autopolyploid origin for L. diversifolia cannot be ruled out nor cytologically nor by other existing data.

No abstract

No abstract

RESUMOO clima organizacional é uma das ferramentas utilizada para avaliar as ações realizadas nas empresas em prol dos colaboradores. Esta pesquisa teve como objetivo avaliar o clima organizacional de uma empresa do setor metalmecânico de Marau/RS a fim de avaliar as ações realizadas pelo Departamento Humano Organizacional (DHO). Para responder a questão problema foram entrevistados os 39 colaboradores da empresa que está há 20 anos no mercado e produz móveis de aço e elevadores de passageiros para edifícios. Os colaboradores responderam um questionário com perguntas fechadas sobre salário, motivação, benefícios, segurança e saúde no local de trabalho, estabilidade no emprego entre outras variáveis. Em seguida foi realizada uma entrevista com o coordenador do DHO, a fim de confrontar os resultados obtidos dos entrevistados. Esta pesquisa teve como método a abordagem qualitativa e quantitativa, além de ser um estudo de caso exploratório. A maioria das variáveis teve um resultado positivo, como a questão de salário com 15% de aprovação, estabilidade no emprego, trabalho em equipe entre outros. Com um resultado insatisfatório destaca-se a variável benefícios com 17% dos colaboradores que nem concordam nem discordam e 12% dos funcionários que discordam em relação aos benefícios oferecidos pela empresa. Palavras chave: Clima Organizacional. Gestão de Pessoas. Motivação. ABSTRACTThe organizational climate is a resource used to assess actions taken in companies on behalf of employees. This research aimed to evaluate the organizational climate on a company of the metalworking sector in Marau/RS to assess the actions performed by its Human Organizational Department (DOH). To meet this purpose, an interview was made with 39 employees of this company, which is on the market for 20 years and produces steel furniture and passenger elevators for buildings. Employees answered a questionnaire with closed questions about salary, motivation, benefits, safety and health in workplace, job stability among other variables. After this, an interview with the DOH coordinator was performed in order to compare with the results obtained from the interviewed employees. This research had a qualitative and quantitative method approach, besides being an exploratory case study. Most variables had a positive result, such as the matter of salary with 15% approval, job stability, teamwork, among others. With an unsatisfactory result, the variable of benefits stands out with 17% of the employees who neither agree nor disagree with it, and 12% of the employees that disagree with the benefits offered by the company.

Resumo -O objetivo deste trabalho foi validar marcadores moleculares previamente associados a genes que conferem resistência à ferrugem-da-folha, em genótipos brasileiros de trigo. Cinco marcadores STS e SCAR, identifi cados como associados aos alelos de resistência dos genes Lr1, Lr9, Lr10 e Lr24, foram avaliados por PCR, em 25 genótipos de trigo com conhecida presença ou ausência desses alelos. O marcador STS, associado ao alelo de resistência do gene Lr1, não foi efi ciente em identifi car genótipos brasileiros que possuem este alelo de resistência. Os marcadores STS e SCAR, associados a Lr9, Lr10 e Lr24, foram efi cientes na identifi cação de plantas que possuem o alelo de resistência desses genes, e podem ser utilizados na seleção por marcadores da resistência à ferrugem-da-folha, em genótipos brasileiros de trigo.Termos para indexação: Puccinia triticina, Triticum aestivum, SCAR, STS. Validation of molecular markers associated to leaf rust resistance genes in wheatAbstract -The objective of this work was to validate molecular markers previously associated to leaf rust resistance genes in Brazilian wheat genotypes. Five STS and SCAR markers identifi ed as associated to the resistance alleles of the genes Lr1, Lr9, Lr10 and Lr24 were tested by PCR in 25 Brazilian wheat genotypes with known presence or absence of these alleles. The STS marker associated to Lr1 was not effi cient in identifying Brazilian genotypes carrying its resistance allele. The STS and SCAR markers associated to Lr9, Lr10 and Lr24 are effi cient in identifying plants carrying the resistance alleles for these genes, and therefore, can be used for marker-assisted selection of leaf rust resistance in Brazilian wheat genotypes.