In Arabidopsis thaliana, the seeds are contained within a silique, which is itself a photosynthetic organ in the early stages of development and undergoes a programme of senescence prior to dehiscence. A transcriptional analysis of the silique wall was undertaken to identify changes in gene expression during senescence and to

selleck compound library correlate these events with ultrastructural changes. The study revealed that the most highly up-regulated genes in senescing silique wall tissues encoded seed storage proteins, and the significance of this finding is discussed. Global transcription profiles of senescing siliques were compared with those from senescing Arabidopsis leaf or petal tissues using microarray datasets and metabolic pathway analysis software (MapMan). In all three tissues, members of NAC and WRKY transcription factor families were up-regulated, but components of the shikimate and cell-wall biosynthetic pathways were down-regulated during senescence. Expression of genes encoding ethylene biosynthesis and action showed more similarity between senescing siliques and petals than between senescing siliques and leaves. Genes involved in autophagy were highly expressed in the late stages of death of all plant tissues studied, but not always during the preceding remobilization phase of senescence. Analyses showed that, during GDC-0973 mouse senescence, silique wall tissues exhibited more transcriptional features in common with petals

than with leaves. The shared and distinct regulatory events associated with senescence in the three organs are evaluated and discussed.”
“BACKGROUND: Mixing in unbaffled vessel with multiple-turbine impellers was studied. The mixing time and mixing power were evaluated in relation to the distance between impellers and the number of impellers. RESULTS: It has been confirmed that frequency of oscillation has no influence on the mixing time and mixing power values or on drag and added mass coefficients. The coefficients

were greater when distance between impellers was smaller. Moreover added mass coefficient was dependent on Reynolds number (ni > 2). Compared with unidirectional mixing conditions, for systems with one type of impeller, the power requirement was about 38% higher for forward-reverse Pitavastatin mixing. Despite the fact that the power demand was greater, the mixing time was not shorter, but about 30% higher than unidirectional mixing in a baffled vessel. However, the forward-reverse mixing mode exhibits a higher level of homogeneity which it achieved faster than unidirectional mixing. CONCLUSION: The power requirements and mixing time for forward-reverse mixing mode were higher in comparison with unidirectional mixing. Despite this, higher values of homogeneity were achieved faster. Higher levels of shear rate and better homogeneity indicate that forward-reverse mixing can be beneficial for multi-phase mixing in vessels with multiple impellers.