ROP/RAC GTPases are master regulators of cell polarity in plants, implicated in the regulation of diverse signaling cascades including cytoskeleton organization, vesicle trafficking, and Ca(2+) gradients [1-8]. The involvement of ROPs in differentiation processes is yet unknown. Here we show the identification of a novel ROP/RAC effector, designated interactor of constitutive active ROPs 1 (ICR1), that interacts with GTP-bound ROPs. ICR1 knockdown or silencing leads to cell deformation and loss of root stem-cell population. Ectopic expression of ICR1 phenocopies activated ROPs, inducing cell deformation of leaf-epidermis-pavement and root-hair cells [3, 5, 6, 9]. ICR1 is comprised of coiled-coil domains and forms complexes with itself and the exocyst vesicle-tethering complex subunit SEC3 [10-13]. The ICR1-SEC3 complexes can interact with ROPs in vivo. Plants overexpressing a ROP- and SEC3-noninteracting ICR1 mutant have a wild-type phenotype. Taken together, our results show that ICR1 is a scaffold-mediating formation of protein complexes that are required for cell polarity, linking ROP/RAC GTPases with vesicle trafficking and differentiation.

Ancient fermented food has been studied based on recipes, residue analysis, and ancient-DNA techniques and reconstructed using modern domesticated yeast. Here, we present a novel approach based on our hypothesis that enriched yeast populations in fermented beverages could have become the dominant species in storage vessels and their descendants could be isolated and studied today. We developed a pipeline of yeast isolation from clay vessels and screened for yeast cells in beverage-related and non-beverage-related ancient vessels and sediments from several archaeological sites. We found that yeast cells could be successfully isolated specifically from clay containers of fermented beverages. The findings that genotypically the isolated yeasts are similar to those found in traditional African beverages and phenotypically they grow similar to modern beer-producing yeast strongly suggest that they are descendants of the original fermenting yeast. These results demonstrate that modern microorganisms can serve as a new tool in bio-archaeology research. IMPORTANCE So far, most of the study of ancient organisms has been based mainly on the analysis of ancient DNA. Here we show that it is possible to isolate and study microorganisms—yeast in this case—from ancient pottery vessels used for fermentation. We demonstrate that it is highly likely that these cells are descendants of the original yeast strains that participated in the fermentation process and were absorbed into the clay matrix of the pottery vessels. Moreover, we characterized the isolated yeast strains, their genomes, and the beer they produced. These results open new and exciting avenues in the study of domesticated microorganisms and contribute significantly to the fields of bio- and experimental archaeology that aim to reconstruct ancient artifacts and products.

34Ancient fermented food has been studied based on recipes, residue analysis and ancient-DNA 35 techniques and reconstructed using modern domesticated yeast. Here, we present a novel 36 approach. We hypothesize that enriched yeast populations in fermented beverages could have 37 become the dominant species in storage vessels and the descendants of these yeast could be 38 isolated and studied long after. To this end, using a pipeline of yeast isolation from clay vessels 39 developed here, we screened for yeast cells in beverage-related and non-related ancient vessels 40 and sediments, from several archeological sites. We found that yeast cells could be successfully 41 isolated specifically from clay containers of fermented beverages. Genomic analysis revealed that 42 these yeast are similar to those found in traditional African beverages. Phenotypically, they grow 43 similar to modern-beer producing yeast. Both strongly suggesting that they are descendants of 44 the original fermenting yeast. These findings provide modern microorganisms as a new tool in 45 bio-archeology. 46Importance 47 So far, most of the study of ancient organisms was based mainly on the analysis of ancient DNA. 48Here we show that it is possible to isolate and study microorganisms, yeast in this case, from 49 thousands of years old clay vessels, used for fermentation. We demonstrate that it is highly likely 50 that these cells are descendants of the original yeast strains which participated in the fermentation 51 process and were absorbed into the pottery vessels. Moreover, we characterize the isolated yeast 52 their genome and the beer they produce. These results open new and exciting avenues in the 53 study of domesticated microorganisms and contribute significantly to the fields of bio and 54 experimental -archeology that aims to reconstruct ancient artifacts and products.55 56 57 58 109 5containers. In contrast, we could not isolate any live yeast from the control vessels which were 110 filled with filtered beer, nor were yeast cells detected by electron microscopy (Fig. 1A, left panel).

No abstract

Background Changes in neuromuscular ability in middle age (MA) may lead to deterioration of postural control. The aim of this study was to investigate the anticipatory response of the peroneus longus muscle (PL) to landing after a single-leg drop-jump (SLDJ), and its postural response after an unexpected leg-drop in MA and young adults. A second aim was to investigate the influence of neuromuscular training on PL postural responses in both age groups. Methods Twenty-six healthy MA (55.3 ± 4 years) and 26 healthy young adults (26.3 ± 3.6 years) participated in the study. Assessments were performed before (T0) and after (T1) PL EMG biofeedback (BF) neuromuscular training. Subjects performed SLDJ, and PL EMG activity in preparation for landing (% of flight time) was calculated. To measure PL time to activation onset and time to peak activation in response to an unexpected leg-drop, subjects stood on a customized trapdoor device that produced a sudden 30° ankle inversion. Results Before training, the MA group showed significantly shorter PL activity in preparation for landing compared to the young adults (25.0% vs. 30.0%, p = 0.016), while after training there was no difference between the groups (28.0% vs. 29.0%, p = 0.387). There were no differences between groups in peroneal activity after the unexpected leg-drop before and after training. Conclusions Our results suggest that automatic anticipatory peroneal postural responses are decreased at MA, whereas reflexive postural responses appear to be intact in this age group. A short PL EMG-BF neuromuscular training may have an immediate positive effect on PL muscle activity at MA. This should encourage the development of specific interventions to ensure better postural control in this group. Trial registration ClinicalTrials.gov NCT05006547.