Dynamics of annatto pigment synthesis and accumulation in seeds of Bixa orellana L. revealed by integrated chemical, anatomical, and RNA-Seq analyses.

Bixin is a commercially valuable apocarotenoid pigment found in the seed aril of Bixa orellana. The dynamics and regulation of its biosynthesis and accumulation during seed development remain largely unknown. Here, we combined chemical, anatomical, and transcriptomic data to provide stage-specific resolution of the cellular and molecular events occurring during B. orellana seed development. Seeds at five developmental stages (S1-S5) were used for analysis of bixin content and seed anatomy, and three of them (S1, S3, and S4) were selected for Illumina HiSeq sequencing. Bixin accumulated in large quantities in seeds compared with other tissues analyzed, particularly during the S2 stage, peaking at the S4 stage, and then decreasing slightly in the S5 stage. Anatomical analysis revealed that bixin accumulated in the large central vacuole of specialized cells, which were scattered throughout the developing mesotesta at the S2 stage, but enlarged progressively at later stages, until they occupied most of the parenchyma in the aril. A total of 13 million reads were generated and assembled into 73,381 protein-encoding contigs, from which 312 were identified as containing 1-deoxy-D-xylulose-5-phosphate/2-C-methyl-D-erythritol-4-phosphate (DOXP/MEP), carotenoid, and bixin pathways genes. Differential transcriptome expression analysis of these genes revealed that 50 of them were sequentially and differentially expressed through the seed developmental stages analyzed, including seven carotenoid cleavage dioxygenases, eight aldehyde dehydrogenases, and 22 methyltransferases. Taken together, these results show that bixin synthesis and accumulation in seeds of B. orellana are a developmentally regulated process involving the coordinated expression of DOXP/MEP, carotenoid, and bixin biosynthesis genes.

Manejo de solo em cultvo com mandioca em treze municípios da região sudoes da Bahia / Soil management with cassava cropping in thirteen counties in the Southwest of Bahia's Region

O Estado da Bahia, por vários anos, destaca-se na produção de mandioca no Brasil, sendo a Região Sudoeste uma das principais produtoras. Em 2003 e 2004, o município de Cândido Sales foi o maior produtor baiano e o segundo maior produtor do Brasil. Entretanto, sua produtividade, assim como a de outros municípios da região, é baixa. As causas para este baixo desempenho são as mais diversas e de difícil detecção, principalmente quando o sistema de produção assume características locais. Com o objetivo de diagnosticar o manejo de solos cultivados com mandioca em 13 municípios da Região Sudoeste da Bahia, foram aplicados 848 questionários, durante o primeiro semestre de 2005, nos municípios de Vitória da Conquista, Barra do Choça, Planalto, Poções, Ribeirão do Largo, Encruzilhada, Cândido Sales, Belo Campo, Tremedal, Piripá, Condeúba, Anagé e Caraíbas. A amostragem foi realizada em cada município, com coleta de informações sobre preparo do solo, utilização de práticas conservacionistas e uso de calagem e adubação. Os dados foram submetidos à análise de freqüência simples. Constatou-se baixa adoção de práticas de conservação do solo, calagem e adubação, predominando nos municípios o preparo do solo manual.

For many years Bahia-Brasil has a highlighted cassava production and the Southwest region of this state is one of the major producer. In 2003 and 2004, Cândido Sales county was the major producer in the state of Bahia and the second higher producer in Brasil. However, its productivity as well as the production from others counties in that region is low. There are many causes for that low performace and can be difficult to be detected, mainly, when the production system ensue local characteristics. With the purpose to diagnosis the soil management cultivated with cassava in thirteen counties in southwest Bahia's region, 848 questionaires were used during the first semester of 2005 in the following counties: "Vitória da Conquista", "Barra do Choça", "Planalto", "Poções", "Ribeirão do Largo", "Encruzilhada", "Cândido Sales", "Belo Campo", "Tremedal", "Piripá", "Condeúba", "Anagé", and "Caraíbas". The sampling was take in each one of counties, with datas about information soil management and liming of the soil manure. The data were under simple frequency analysis. It was observed low adoption soil preservation thecnologies, lime and manure, prevailing in counties the soil preparation manual.