Tackling plant phosphate starvation by the roots

Plant responses to phosphate deprivation encompass a wide range of strategies, varying from altering root system architecture, entering symbiotic interactions to excreting root exudates for phosphorous release, and recycling of internal phosphate. These processes are tightly controlled by a complex network of proteins that are specifically upregulated upon phosphate starvation. Although the different effects of phosphate starvation have been intensely studied, the full extent of its contribution to altered root system architecture remains unclear. In this review, we focus on the effect of phosphate starvation on the developmental processes that shape the plant root system and their underlying molecular pathways

Winning or not losing? The impact of non-pain goat focus on attentional bias to learned pain signals

Background and aims Insights into the nature of cognitive bias, including attentional bias to threat signals, are considered pivotal to understanding (chronic) pain and related distress. It has been put forward that attention to pain-related threat is normally dynamic and relates to the motivational state of the individual. In this experiment we aimed (i) to replicate the finding that attentional bias for pain signals in healthy participants can be reduced when a non-pain goal is pursued, and (ii) to extend this finding by taking into account the outcome focus of the non-pain goal. We hypothesised that the reduction in attentional bias for pain signals by concurrent non-pain goal pursuit would be stronger with non-pain prevention goals than with promotion goals. Methods Healthy university students performed an attentional bias task (i.e. spatial cueing task) containing visual cues that signalled the possible occurrence of a painful stimulus (electrocutaneous stimulus at tolerance level) or its absence, in combination with a non-pain goal task (i.e. digit naming task). The non-pain goal was either related to acquiring a positive outcome (gaining money depending on digit-naming performance; promotion goal group, n=31) or related to avoiding a negative outcome (losing money; prevention goal group, n=31). A standard attentional bias task served as the control condition (control group, n=31). Results Spatial cueing effects were larger for pain cues than for no-pain cues, indicating attentional bias for pain signals. The pattern of results suggests that this effect was indeed reduced in the goal groups as compared to the control group, but there was no significant group difference. Conclusions We found no statistically-significant evidence for the impact of non-pain goal pursuit or outcome focus on pain-related attentional bias. At best, there were indications of a reduced attentional bias for pain signals with non-pain goal pursuit that was either promotion- or prevention focused. Implications These data add to the small but growing body of literature on the assumed relevance of motivational context in explaining variations in attentional bias. The results trigger new questions on the nature and assessment of pain-related attentional bias, and more specifically attentional bias for fear-conditioned pain signals (versus safety signals), from a motivational perspective.status: publishe

Lateral root inducible system in Arabidopsis and maize

Lateral root development contributes significantly to the root system, and hence is crucial for plant growth. The study of lateral root initiation is however tedious, because it occurs only in a few cells inside the root and in an unpredictable manner. To circumvent this problem, a Lateral Root Inducible System (LRIS) has been developed. By treating seedlings consecutively with an auxin transport inhibitor and a synthetic auxin, highly controlled lateral root initiation occurs synchronously in the primary root, allowing abundant sampling of a desired developmental stage. The LRIS has first been developed for Arabidopsis thaliana, but can be applied to other plants as well. Accordingly, it has been adapted for use in maize (Zea mays). A detailed overview of the different steps of the LRIS in both plants is given. The combination of this system with comparative transcriptomics made it possible to identify functional homologs of Arabidopsis lateral root initiation genes in other species as illustrated here for the CYCLIN B1; 1 (CYCB1; 1) cell cycle gene in maize. Finally, the principles that need to be taken into account when an LRIS is developed for other plant species are discussed

Winning or not losing? The impact of non-pain goat focus on attentional bias to learned pain signals:The impact of non-pain goal focus on attentional bias to learned pain signals

BACKGROUND AND AIMS: Insights into the nature of cognitive bias, including attentional bias to threat signals, are considered pivotal to understanding (chronic) pain and related distress. It has been put forward that attention to pain-related threat is normally dynamic and relates to the motivational state of the individual. In this experiment we aimed (i) to replicate the finding that attentional bias for pain signals in healthy participants can be reduced when a non-pain goal is pursued, and (ii) to extend this finding by taking into account the outcome focus of the non-pain goal. We hypothesised that the reduction in attentional bias for pain signals by concurrent non-pain goal pursuit would be stronger with non-pain prevention goals than with promotion goals. METHODS: Healthy university students performed an attentional bias task (i.e. spatial cueing task) containing visual cues that signalled the possible occurrence of a painful stimulus (electrocutaneous stimulus at tolerance level) or its absence, in combination with a non-pain goal task (i.e. digit naming task). The non-pain goal was either related to acquiring a positive outcome (gaining money depending on digit-naming performance; promotion goal group, n=31) or related to avoiding a negative outcome (losing money; prevention goal group, n=31). A standard attentional bias task served as the control condition (control group, n=31). RESULTS: Spatial cueing effects were larger for pain cues than for no-pain cues, indicating attentional bias for pain signals. The pattern of results suggests that this effect was indeed reduced in the goal groups as compared to the control group, but there was no significant group difference. CONCLUSIONS: We found no statistically-significant evidence for the impact of non-pain goal pursuit or outcome focus on pain-related attentional bias. At best, there were indications of a reduced attentional bias for pain signals with non-pain goal pursuit that was either promotion- or prevention focused. IMPLICATIONS: These data add to the small but growing body of literature on the assumed relevance of motivational context in explaining variations in attentional bias. The results trigger new questions on the nature and assessment of pain-related attentional bias, and more specifically attentional bias for fear-conditioned pain signals (versus safety signals), from a motivational perspective