Racial differences in systemic sclerosis disease presentation: a European Scleroderma Trials and Research group study

Objectives. Racial factors play a significant role in SSc. We evaluated differences in SSc presentations between white patients (WP), Asian patients (AP) and black patients (BP) and analysed the effects of geographical locations.Methods. SSc characteristics of patients from the EUSTAR cohort were cross-sectionally compared across racial groups using survival and multiple logistic regression analyses.Results. The study included 9162 WP, 341 AP and 181 BP. AP developed the first non-RP feature faster than WP but slower than BP. AP were less frequently anti-centromere (ACA; odds ratio (OR) = 0.4, P < 0.001) and more frequently anti-topoisomerase-I autoantibodies (ATA) positive (OR = 1.2, P = 0.068), while BP were less likely to be ACA and ATA positive than were WP [OR(ACA) = 0.3, P < 0.001; OR(ATA) = 0.5, P = 0.020]. AP had less often (OR = 0.7, P = 0.06) and BP more often (OR = 2.7, P < 0.001) diffuse skin involvement than had WP.AP and BP were more likely to have pulmonary hypertension [OR(AP) = 2.6, P < 0.001; OR(BP) = 2.7, P = 0.03 vs WP] and a reduced forced vital capacity [OR(AP) = 2.5, P < 0.001; OR(BP) = 2.4, P < 0.004] than were WP. AP more often had an impaired diffusing capacity of the lung than had BP and WP [OR(AP vs BP) = 1.9, P = 0.038; OR(AP vs WP) = 2.4, P < 0.001]. After RP onset, AP and BP had a higher hazard to die than had WP [hazard ratio (HR) (AP) = 1.6, P = 0.011; HR(BP) = 2.1, P < 0.001].Conclusion. Compared with WP, and mostly independent of geographical location, AP have a faster and earlier disease onset with high prevalences of ATA, pulmonary hypertension and forced vital capacity impairment and higher mortality. BP had the fastest disease onset, a high prevalence of diffuse skin involvement and nominally the highest mortality

Noninvasive 3D Root Imaging

The influence of roots on plant productivity has often been neglected because of the difficulties to access and monitor the root system architecture and function. The goals of this work are to establish methods to noninvasively image 3D root system architecture (RSA) in 3D, to identify structural and functional root traits, to monitor the development of plant root traits during development and, in particular, to identify traits of resource efficient roots. Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) are two modalities which enable observing structural and functional properties of roots growing in soil in a noninvasive manner. The existing 4.7T MRI System has been shown to produce 3D images with a high root to soil contrast [1]. Due to the installed prototypic robot system these data sets can be acquired automatically, including measurements during the night and on weekends, leading to a considerable amount of raw data. To enable calculation of RSA traits and their development over time, a software tool has been developed capable of extracting the RSA from the MRI measurement data automatically. Methods to manually correct the automatically extracted RSA have been implemented. Typical root traits calculated from the extracted RSA are shown, including a comparison to an invasive method (WinRhizo).Functional information, in particular of carbon transport, of intact root systems can be obtained by positron emission tomography (PET). Radioactively labelled [11C]-CO2 is taken up by photosynthesis and radiolabelled metabolites (tracer) are eventually transported into the root system. The existing PET system (PlanTIS [1]) is used for test experiments though its detection sensitivity is too low to characterize transport properties. To overcome the drawbacks of PlanTIS, a new PET system (phenoPET) has been developed together with Philips Photon Counting and two institutes at Forschungszentrum Jülich (ZEA-1 and ZEA-2). The phenoPET is currently being assembled and will be delivered in 2015. Compared to PlanTIS, the new phenoPET system will provide higher sensitivity and a larger field of view, two important factors to enable functional phenotyping.Literature:[1] Jahnke et al.: Combined MRI–PET dissects dynamic changes in plant structures and functions. The Plant Journal (2009) 59, 634–64

Water uptake of main root segments in a multiple compartment root container

IntroductionThe root hydraulic conductances, and how they are affected by root anatomy and or root aging, are currently poorly understood, despite the importance of the hydraulic conductivities for water uptake, especially in drought environments. Here we describe a multi compartment container that reduces root intermingling and minimizes water movement between soil compartments. Additionally, a Magnetic Resonance Imaging (MRI) compatible soil water sensor was developed which can be inserted into each compartment for soil water monitoring.MethodsWe constructed a multi compartment container (up to 13 compartments) filled with quartz sand and mixed with sieved loamy soil taken from an agricultural plot (9:1). MRI was used to quantify root development within each compartment as was the local amount of soil water in each compartment. The soil water content was also monitored using home designed soil water sensors which readings used to adjust the water content in each compartment during growth. Results and discussionUsage of this soil mix allowed visualization of a major fraction of Brachypodium laterals. Maize plant growth was not obviously changed by the multi compartment container during 6 weeks of growth. Root development was successfully measured within each compartment and the water content was monitored at different growth stages using optimized MRI protocols. During growth the soil water content for each compartment could be adjusted according to the readings of the soil water sensors that were also found not to diminish MRI image quality.ConclusionThe combination of a multi compartment container, MRI measurements of roots and soil water and the use of newly designed soil water sensors, allows the monitoring of root water uptake of individual root segments. This combination is therefore promising to study the effects of root age and anatomy on water uptake and the effects of nutrients on growth of different root classes

Spatio-Temporal Variation in Water Uptake in Seminal and Nodal Root Systems of Barley Plants Grown in Soil

The spatial and temporal dynamics of root water uptake in nodal and seminal roots are poorly understood, especially in relation to root system development and aging. Here we non-destructively quantify 1) root water uptake and 2) root length of nodal and seminal roots of barley in three dimensions during 43 days of growth. We developed a concentric split root system to hydraulically and physically isolate the seminal and nodal root systems. Using magnetic resonance imaging (MRI), roots were visualized, root length was determined, and soil water depletion in both compartments was measured. From 19 days after germination and onwards, the nodal root system had greater water uptake compared to the seminal root system due to both greater root length and greater root conductivity. At 29 days after germination onwards, the average age of the seminal and nodal root systems was similar and no differences were observed in water uptake per root length between seminal and nodal root systems, indicating the importance of embryonic root systems for seedling establishment and nodal root systems in more mature plants. Since nodal roots perform the majority of water uptake at 29 days after germination and onwards, nodal root phenes merit consideration as a selection target to improve water capture in barley and possibly other crops

Spatially Resolved Root Water Uptake Determination Using a Precise Soil Water Sensor

To answer long-standing questions about how plants use and regulate water, an affordable, noninvasive way to determine localroot water uptake (RWU) is required. Here, we present a sensor, the soil water profiler (SWaP), which can determine local soilwater content (u) with a precision of 6.10 25 cm 3 $cm 23 , an accuracy of 0.002 cm 3$ cm 23 , a temporal resolution of 24 min, and aone-dimensional spatial resolution of 1 cm. The sensor comprises two copper sheets, integrated into a sleeve and connected to acoil, which form a resonant circuit. A vector network analyzer, inductively coupled to the resonant circuit, measures theresonance frequency, against which u was calibrated. The sensors were integrated into a positioning system, which measuresu along the depth of cylindrical tubes. When combined with modulating light (4-h period) and resultant modulating planttranspiration, the SWaP enables quantification of the component of RWU distribution that varies proportionally with total plantwater uptake, and distinguishes it from soil water redistribution via soil pores and roots. Additionally, as a young, growingmaize (Zea mays) plant progressively tapped its soil environment dry, we observed clear changes in plant-driven RWU and soilwater redistribution profiles. Our SWaP setup can measure the RWU and redistribution of sandy-soil water content withunprecedented precision. The SWaP is therefore a promising device offering new insights into soil–plant hydrology, withapplications for functional root phenotyping in nonsaline, temperature-controlled conditions, at low cost