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Managing ecosystems to sequester soil carbon requires a thorough understanding of complex soil processes. Here, we integrate these soil processes through the metaphor of a game—one that moves through multiple dimensions (from macro‐aggregates to micropores and clay particles) and scales (from centimeters to nanometers) of the soil. The rules of the game are based on current understanding of soil carbon persistence, which differs from the classic humus concept of molecular complexity. The game's objective is to win points, by keeping "tokens" (plant‐derived organic compounds) within the soil organic matter for as long as possible. The game begins when tokens enter different "pool‐levels" (plant litter, particulate organic matter, dissolved organic matter, and mineral‐associated organic matter) of the soil, either directly or after metabolic transformation by soil biota. Points are lost through either respiration by soil biota or leaching. We invite readers to play this game and explore different natural ecosystems and land‐use scenarios to better comprehend complex soil processes. [ABSTRACT FROM AUTHOR]

Biochar is being used with increasing frequency as a soil remediator. However, its impact depends on soil limitations, biochar source and concentration applied. We studied Guadua chacoensis bamboo biochar as a saline-alkaline soil amendment. Aqueous solutions with 0, 2.5 and 5% of bamboo biochar (BC) were used to determine their influence on seed germination rate and radicle length in two horticultural species moderately tolerant to salinity and alkalinity: arugula (Eruca sativa) and radish (Raphanus sativus). Also, we amended a saline-alkaline soil with 0, 0.5 and 2.5% of BC to evaluate its effect on plant height, leaf and root biomass of both horticultural crops. The application of 2.5 and 5% BC solution decreased arugula germination in 3.14% and 5.2%, respectively, compared to 0% BC. The addition of BC decreased radicle length in both species and such reduction was more significant with the higher BC concentration. The addition of 0.5% and 2.5% BC as amendment in a saline-alkaline soil decreased arugula height in 27.32% and 50.33%, respectively, compared to 0% BC, resulting in smaller plants with less leaf and root biomass. The BC amendment did not affect leaf biomass, but 2.5% BC reduced root biomass in 53.85% compared to 0% BC. These results seem to be influenced not only by the BC inherent characteristics but also by the increase in soil pH, caused by the addition of biochar. Further studies may evaluate the impact of BC addition with different properties on saline-alkaline soils, and its use as an amendment in the remediation of acid soils. [ABSTRACT FROM AUTHOR]

Crucial to our understanding of plant ecology is the consideration of the eco‐physiological responses and constraints of plant–fungal symbioses throughout the native distribution range of their host.We examined key eco‐physiological roles of two co‐occurring fungal symbionts [Epichloë endophytes and arbuscular mycorrhizal fungi (AMF)] in the endemic grass Hordeum comosum across a wide bioclimatic gradient and contrasting grazing severity. We sampled H. comosum plants along four humid‐to‐arid transects in Patagonia, Argentina, covering its entire distribution range and determined Epichloë presence, AMF root colonization, nitrogen and phosphorus concentration, intrinsic water‐use efficiency (iWUE, the ratio of photosynthesis to stomatal conductance) and 18O‐enrichment of cellulose in shoots.Root colonization by AMF increased with Epichloë presence. All plants hosted Epichloë in the humid range of the gradient, but symbioses occurrence decreased towards arid sites which also displayed severe grazing symptoms at site level.Symbiosis with Epichloë correlated positively with shoot nitrogen concentration in the centre of the distribution range, and with shoot phosphorus concentration across the entire distribution range.The site‐level relationship of AMF colonization with 18O‐enrichment and iWUE suggested that mycorrhiza boosted stomatal conductance in humid environments but curbed it in arid environments.While the interpretation of interactions and potential causalities from observational studies should be done with caution, this study demonstrates distinct correlations between plant–fungal symbiont associations and key resource parameters (phosphorus, nitrogen and iWUE vs. 18O‐enrichment). Such correlations may suggest particular functional roles for these symbionts in the ecology of their host plant. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Remediation of saline-sodic soils used for cattle breeding is particularly challenging due to the limited alternatives. We hypothesize that introducing salt tolerant and productive forage in a lowland halophytic steppe, typical of saline-sodic soils, increases belowground biomass inputs and activity, generating a series of positive effects on soil biological and chemical properties, and aggregate stability – an accepted indicator of soil degradation resistance. Under natural environmental conditions, we found that the introduction of Panicum coloratum (panicum) increased belowground biomass almost three times, the abundance of mites tended to be greater and that of springtails was 9.4 kg−1 contrasting with none found in the halophytic steppe, after 7 years. The concentration of Ca2+ and Mg2+ increased 26% and 54%, respectively, and that of Na+ was reduced 31% compared with the halophytic steppe. Soil pH decrease 5% and electrical conductivity decreased 37% (changing from moderate to very slightly saline) in panicum compared to the halophytic steppe. However, in panicum, mineral-associated organic matter (MAOM) and aggregate stability decreased 22% and 26%, respectively. We concluded that, although biological and chemical properties improved, aggregate stability – an early indicator of soil recovery – decreased, which was likely determined by MAOM reduction in saline-sodic soils. [ABSTRACT FROM AUTHOR]

BACKGROUND: The effect of plant size (seedlings versus young plants versus adult plants) on the phenotypic level of glyphosate resistance and selection intensity (SI) in Sorghum halepense with and without a reduced glyphosate translocation resistance mechanism was evaluated. RESULTS: Resistance parameters [the 50% lethal dose (LD50) and the dose required to cause a 50% reduction in plant growth (GR50)] in adult plants were notably higher than in seedlings regardless of the resistance status. However, under similar plant size increases, populations comprised of glyphosate‐resistant (R) individuals showed higher survival and growth when glyphosate treated compared with glyphosate‐susceptible (S) plants. An increase in SI was always evident with increasing glyphosate doses. However, the rate of increase in SI was higher under glyphosate selection of young R and S plants, followed by seedlings and adult R and S plants. However, in conditions of R seedlings coexisting with adult S plants under glyphosate treatment (1000–4000 g ha−1), selection against glyphosate resistance was observed. CONCLUSION: Any increase in size from the seedling stage of R plants translates into an amplification of resistance. Depending on the particular size combinations of spatially coexisting R and S plants, selection for glyphosate resistance may be faster, slower or even not evident. © 2018 Society of Chemical Industry Depending on the particular size combination of spatially coexisting glyphosate‐resistant (R) and susceptible (S) plants, the intensity of glyphosate selection may increase or decrease under increasing glyphosate doses. [ABSTRACT FROM AUTHOR]

Waterlogging imposes severe stress to the plant, and the interplay between root and aerial organs in the adjustment to this stress is poorly understood. A set of recombinant inbred lines ( RILs) of L otus japonicus ( Gifu B-129 × Miyakojima MG-20) was subjected to control and waterlogging conditions for 21 d, and 12 traits related to leaf physiological functioning, root aerenchyma formation, shoot and root morphology, and dry mass accumulation were assessed to generate phenomic networks. The phenomic network became more complex under waterlogging as a result of the incorporation of root aerenchyma and dark-adapted Fv/ Fm. Significant waterlogging-induced variation was found for stomatal conductance, dark-adapted Fv/ Fm and aerenchyma. The RILs with stronger induction of aerenchyma in response to waterlogging tended to show reduced negative impact of this stress on root growth but suffered average impact on shoot growth. The RILs that retained higher stomatal conductance under waterlogging tended to retain higher dark-adapted Fv/ Fm and shoot growth under waterlogging conditions but showed average impact on root traits. We propose a model where, although the stress experienced by the roots during waterlogging is transmitted to the shoot, shoots and roots deal with waterlogging in a less interdependent manner than often assumed. [ABSTRACT FROM AUTHOR]

Symbiosis between cool-season grasses and vertically transmitted fungal endophytes are common and significantly impact on ecosystem function. This makes the understanding of the underlying mechanisms to symbiotic individuals frequency in local populations much more interesting. Most studies have been focused on the differential fitness between symbiotic and non-symbiotic counterparts (relative fitness), barely considering other mechanisms. We performed a microcosms experiment to evaluate whether grazing alters the dynamics of the endophyte Neotyphodium occultans in the annual grass Lolium multiflorum by simultaneously modifying the relative fitness and the endophyte efficiency to be transmitted from host plants to seeds. Grazing was simulated by means of clipping and trampling on symbiotic and non-symbiotic plants growing separately, in soils obtained from paddocks, differing in their agronomic management history (natural grassland vs. ryegrass promotion). Seed production showed a complex pattern as it depended on the symbiotic status of the plants, the level of grazing and the agro-ecological context. Grazed plants produced three times fewer seeds than ungrazed plants only in microcosms with endophyte-symbiotic plants in soils from ryegrass promotion. Endophyte benefits on seed production were exclusively observed in ungrazed plants in the same soil. Symbiotic plants produced symbiotic and non-symbiotic seeds in all the treatments. While the production of non-symbiotic seeds by these plants was not affected by grazing and the soil, grazing reduced the production of symbiotic seeds in both contexts. Grazing negative effect on the density of fully infected spikes determined a significant increment in the transmission failures which were not modified by agro-ecological contexts. Therefore, grazing can modulate symbiosis dynamics through reducing seed production and endophyte transmission efficiency. Transmission has been disregarded, but it is a context-dependent process that could lead to a gradual reduction in the symbiotic plants frequency in a population if the mutualism effectiveness does not outweigh transmission failures. [ABSTRACT FROM AUTHOR]

Background: Mycophenolate mofetil (MMF) is a largely used immunosuppressive agent in the prevention of transplant rejection and lupus nephritis. Its use has been extended to other immune-mediated diseases (ID)., Aim: To assess the off-label use of MMF, its performance as a glucocorticoid sparing agent, the therapeutic response, and its adverse effects., Material and Methods: A retrospective study was performed. One hundred-seven patients aged 58 ± 16 years (83% females) who received MMF for ID in off label uses between 2016 and 2018 were included. The study variables were cause of MMF indication, sex, age, use as a first- or second-line treatment and maintenance dosing. The cumulative doses of glucocorticoids six months before and after MMF indication were compared., Results: MMF was used as a second-line therapy in 66 patients (62%). The mean maintenance dose of MMF was 1,500 ± 540 mg/day. Prednisone cumulative doses were 3,908 ± 2,173 and 1,672 ± 1,083 milligrams six months before and six months after starting MMF, respectively (p < 0.01). Adverse effects were identified in 21 (20%) cases, none of them serious., Conclusions: Mycophenolate has a favorable response profile as a second line immunosuppressive agent. It is effective as a glucocorticoid sparing drug. The safety profile is also favorable as adverse effects were scanty and mild.

Background: The effect of plant size (seedlings versus young plants versus adult plants) on the phenotypic level of glyphosate resistance and selection intensity (SI) in Sorghum halepense with and without a reduced glyphosate translocation resistance mechanism was evaluated., Results: Resistance parameters [the 50% lethal dose (LD 50 ) and the dose required to cause a 50% reduction in plant growth (GR 50 )] in adult plants were notably higher than in seedlings regardless of the resistance status. However, under similar plant size increases, populations comprised of glyphosate-resistant (R) individuals showed higher survival and growth when glyphosate treated compared with glyphosate-susceptible (S) plants. An increase in SI was always evident with increasing glyphosate doses. However, the rate of increase in SI was higher under glyphosate selection of young R and S plants, followed by seedlings and adult R and S plants. However, in conditions of R seedlings coexisting with adult S plants under glyphosate treatment (1000-4000 g ha -1 ), selection against glyphosate resistance was observed., Conclusion: Any increase in size from the seedling stage of R plants translates into an amplification of resistance. Depending on the particular size combinations of spatially coexisting R and S plants, selection for glyphosate resistance may be faster, slower or even not evident. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)