Based on so far revealed features of these mutants and pharmacological compounds, these results confirmed cGMP as a Ca(2+)-mobilizing second messenger for apoplastic auxin whose perception and transduction would implicate a seven-transmembrane receptor – G protein – guanylyl cyclase unit at the guard cell plasma membrane. (C) 2010 Elsevier

Masson SAS. All rights reserved.”
“The morphology and molecular mechanisms see more of animal photoreceptor cells and eyes reveal a complex pattern of duplications and co-option of genetic modules, leading to a number of different light-sensitive systems that share many components, in which clear-cut homologies are rare. On the basis of molecular and morphological findings, I discuss the functional requirements for vision and how these have constrained the evolution of eyes. The fact that natural selection on eyes acts through the consequences of visually guided behaviour leads to a concept

of task-punctuated evolution, where sensory systems evolve by a sequential acquisition of sensory tasks. I identify SNX-5422 in vivo four key innovations that, one after the other, paved the way for the evolution of efficient eyes. These innovations are (i) efficient photopigments, (ii) directionality through screening pigment, (iii) photoreceptor membrane folding, and (iv) focusing optics. A corresponding evolutionary sequence is suggested, starting at non-directional monitoring of ambient luminance and leading to comparisons of luminances within a scene, first by a scanning mode and later by parallel spatial channels in imaging eyes.”
“P>Under natural conditions, it is common for plants to experience water deprivation PARP activity (drought) for periods of days or longer. Plants respond to drought stress by reconfiguring their transcriptome activity. Transcriptome

changes in response to drought are dynamic, and are shaped by mitigating factors like time during the diurnal cycle. To date, analyses of drought-induced transcriptome remodelling have concentrated on dynamic changes induced by rapid desiccation, or changes at a single time point following gradual water stress. To gain insights into the dynamics of transcriptome reconfiguration in response to gradual drying of the soil, the drought-induced transcriptomes of Arabidopsis thaliana were examined at four time points over a single diel period – midday, late day, midnight, and pre-dawn. Transcriptome reconfigurations were induced by drought in advance of changes to relative water content, leaf water loss, and chlorophyll content. Comparative analyses support the hypothesis that the drought-responsive transcriptomes were shaped by invocation of distinct hormonal and stress response pathways at different times of the day. While a core set of genes were drought responsive at multiple time points throughout the day, the magnitude of the response varied in a manner dependent on the time of day.