RESUMO
Barley (Hordeum vulgare) is an important global cereal crop and a model in genetic studies. Despite advances in characterising barley genomic resources, few mutant studies have identified genes controlling root architecture and anatomy, which plays a critical role in capturing soil resources. Our phenotypic screening of a TILLING mutant collection identified line TM5992 exhibiting a short-root phenotype compared with wild-type (WT) Morex background. Outcrossing TM5992 with barley variety Proctor and subsequent SNP array-based bulk segregant analysis, fine mapped the mutation to a cM scale. Exome sequencing pinpointed a mutation in the candidate gene HvPIN1a, further confirming this by analysing independent mutant alleles. Detailed analysis of root growth and anatomy in Hvpin1a mutant alleles exhibited a slower growth rate, shorter apical meristem and striking vascular patterning defects compared to WT. Expression and mutant analyses of PIN1 members in the closely related cereal brachypodium (Brachypodium distachyon) revealed that BdPIN1a and BdPIN1b were redundantly expressed in root vascular tissues but only Bdpin1a mutant allele displayed root vascular defects similar to Hvpin1a. We conclude that barley PIN1 genes have sub-functionalised in cereals, compared to Arabidopsis (Arabidopsis thaliana), where PIN1a sequences control root vascular patterning.
RESUMO
The root system of plants is a vital part for successful development and adaptation to different soil types and environments. A major determinant of the shape of a plant root system is the formation of lateral roots, allowing for expansion of the root system. Arabidopsis thaliana, with its simple root anatomy, has been extensively studied to reveal the genetic program underlying root branching. However, to get a more general understanding of lateral root development, comparative studies in species with a more complex root anatomy are required. Here, by combining optimized clearing methods and histology, we describe an atlas of lateral root development in Brachypodium distachyon, a wild, temperate grass species. We show that lateral roots initiate from enlarged phloem pole pericycle cells and that the overlying endodermis reactivates its cell cycle and eventually forms the root cap. In addition, auxin signaling reported by the DR5 reporter was not detected in the phloem pole pericycle cells or young primordia. In contrast, auxin signaling was activated in the overlying cortical cell layers, including the exodermis. Thus, Brachypodium is a valuable model to investigate how signaling pathways and cellular responses have been repurposed to facilitate lateral root organogenesis.
RESUMO
INTRODUCTION: The aim of this study was to examine the association between the injury mechanism and repair type with outcomes in patients with traumatic inferior vena cava injuries. METHODS: This is a retrospective analysis of the ACS-TQIP database (2017-2020), including patients with traumatic IVC injuries. Patients were stratified by injury mechanism and type of repair and compared. RESULTS: Out of 1334 patients, 5 â% underwent endovascular repair while 95 â% had an open procedure. Overall, 74.7 â% sustained a penetrating injury. On multivariable regression analysis, the type of repair was not associated with mortality and morbidity for patients with penetrating injuries. However, among patients with blunt injuries, endovascular repair was associated with lower odds of in-hospital mortality (aOR:0.35, p â= â0.020) and non-venous thromboembolism (VTE) morbidity (aOR:0.41, p â= â0.015), and higher odds of VTE complications (aOR:6.74, p â< â0.001). CONCLUSIONS: Although the type of repair did not impact morbidity and mortality in patients with penetrating injuries, endovascular repair was identified as the only modifiable predictor of reduced non-VTE morbidity and mortality in patients with blunt injuries.