Genome-Wide Identification and Characterization of the <i>Dof</i>Transcription Factor Gene Family in <i>Phaseolus vulgaris</i>L.

The Dof (DNA-binding with one finger) proteins are a class of plant-specific transcription factors that can trigger several processes involved in plant growth and development, as well as in stress responses. Here, we performed a systematic bioinformatics analysis to characterize all Dof genes in common bean, which included analysis of the genome sequence, conserved protein domains, chromosomal locations, subcellular locations, phylogenetic relationships, gene duplications, and gene expression profiles in different tissues. Bioinformatics analysis revealed 36 putative genes related to PvDof that were classified into seven subfamilies (A, B1, B2, C1, C2, D1, and, D2) by comparative phylogenetic analysis. Based on our genome duplication analysis, a total of 36 genes were found to be distributed on all 11 chromosomes, and they expanded through gene duplication in tandem, suggesting the involvement of segmental duplication events in the evolutionary process. Synteny events and phylogenetic comparisons of the Dof proteins of common bean with those of A. thaliana, O. sativa, and G. max L. led to the identification of several orthologous and paralogous genes, which provided further insight into the diversity of the evolutionary characteristics of genes of this family in other plant species. Expression profiles revealed that most of the PvDof genes were expressed in different tissues, indicating that PvDof genes may be involved in various physiological functions during plant development. The results of this study provide additional information and potential biotechnological resources for further understanding the molecular basis of this gene family and consequently improvement of common bean crops.

Diversity among Isolates of the Tangerine Pathotype of Alternaria alternata

The tangerine pathotype of Alternaria alternata is the aetiological agent of Alternaria brown spot on tangerines. In the state of Paraíba, Brazil, its occurrence on “Dancy” tangerine trees is associated with genetic aspects as well as the influence of environmental conditions on reproduction and dissemination within and between populations. The aim of the present study was to evaluate the diversity of isolates of this pathogen using morphophysiological and molecular markers. For the analysis of mycelial growth and sporulation, 30 isolates from different locations were examined at 24-hour intervals until the seventh day, when the spores were quantified. The 30 isolates were characterised based on molecular markers (ISSR) and genetic similarity (Jaccard index). A factor arrangement was used: 30 isolates, four media (ODA, PDA, LEA and V8), three light regimes (continuous dark, alternating light and continuous light) and three temperatures (15°C, 25°C and 35°C), with 12 repetitions. Groups 1, 2 and 3 presented low genetic variability. Group 4 showed high genetic variability of the isolates obtained from the Massaranduba (state of Paraíba-Brazil) producing region and higher mycelial growth and sporulation of A. alternata. The continuous light regime and the temperature 25°C in PDA and V8 media were the ideal conditions for the mycelial growth and sporulation, respectively, of the isolates of A. alternata.

Root Growth, Nutrition and Yield of Maize with Applied Different Limestone Particle Size in the Cerrado Soil

The limestone with smaller particle size provides rapid correction of soil acidity. However, the limestone with large particles can promote bigger root growth, and may still have a residual effect on the soil. The aim of this study was to evaluate the residual effect of the application and incorporation of different limestone with a particle size bigger than 0.30 mm in root growth, nutrition and yield of maize in Cerrado soil. A randomized completed block utilized in this experiment, with five treatments and four replications. The grain sizes of dolomitic limestone incorporated into the Oxisol were: 0 (control, no-lime), 2.00-0.82 mm, 0.82-0.56 mm, 0.56-0.30 mm, 0.30-0.20 mm, in doses of 6.5 t·ha-1, 3.9 t·ha-1, 2.6 t·ha-1 and 1.3 t·ha-1 respectively. The limestone applied in introduction no-tillage. The maize were evaluated of root attributes, nutrition and grain yield in two years 2009 and 2010. The use of limestone particle size of 2.00-0.82 mm, and the quantity of 6.5 t·ha-1 applied to the soil and incorporated showed elongation and root growth of maize thin depth of 20-40 cm in the soil. In that, same proposed management of the limestone was the highest maize grain yield in the first year. The rooting characteristics evaluated correlated with leaf Ca and Cu and maizegrain yield.

Root Growth, Nutrition and Yield of Maize with Applied Finely Limestone in Surface of Cerrado Soil

The surface applies lime to correcting soil acidity in no-tillage and promotes root development and yield of maize. However, limestone with a particle size smaller than 0.30 mm cannot promote this effect. The aim of this study was to determine the root attributes, nutrition and productivity of maize with limestone ground in no-tillage. The experimental design was randomized blocks with five treatments and four replications. The treatments consisted of different particle sizes of limestone applying superficially to the soil under NT 0) control, without lime, 1) 0.30 mm to 0.20 mm 2) 0.20 mm to 0.10 mm, 3) 0, 10 mm to 0.05 mm 4) 0.05 mm to 0.01 mm. Attributes root, leaf nutrition and grain yield of maize were evaluated in two years 2009 and 2010. The elongation of roots in a 20-40 cm depth was greater when using limestone with particle size between 0.30 mm and 0.20 mm. The root length of maize plants correlated with the levels of Mn in maize leaves. The root development promoted by liming effect was not reflected in the productivity of maize.