Browsing by Author "Hauser, E"

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Open Access
GxE interactions between FOXO genotypes and drinking tea are significantly associated with prevention of cognitive decline in advanced age in China.
(J Gerontol A Biol Sci Med Sci, 2015-04) Zeng, Y; Chen, H; Ni, T; Ruan, R; Feng, L; Nie, C; Cheng, L; Li, Y; Tao, W; Gu, J; Land, KC; Yashin, A; Tan, Q; Yang, Z; Bolund, L; Yang, H; Hauser, E; Willcox, DC; Willcox, BJ; Tian, X; Vaupel, JW
Logistic regression analysis based on data from 822 Han Chinese oldest old aged 92+ demonstrated that interactions between carrying FOXO1A-266 or FOXO3-310 or FOXO3-292 and tea drinking at around age 60 or at present time were significantly associated with lower risk of cognitive disability at advanced ages. Associations between tea drinking and reduced cognitive disability were much stronger among carriers of the genotypes of FOXO1A-266 or FOXO3-310 or FOXO3-292 compared with noncarriers, and it was reconfirmed by analysis of three-way interactions across FOXO genotypes, tea drinking at around age 60, and at present time. Based on prior findings from animal and human cell models, we postulate that intake of tea compounds may activate FOXO gene expression, which in turn may positively affect cognitive function in the oldest old population. Our empirical findings imply that the health benefits of particular nutritional interventions, including tea drinking, may, in part, depend upon individual genetic profiles.
Open Access
Interaction Between the FOXO1A-209 Genotype and Tea Drinking Is Significantly Associated with Reduced Mortality at Advanced Ages.
(Rejuvenation Res, 2016-06) Zeng, Y; Chen, H; Ni, T; Ruan, R; Nie, C; Liu, X; Feng, L; Zhang, F; Lu, J; Li, J; Li, Y; Tao, W; Gregory, SG; Gottschalk, W; Lutz, MW; Land, KC; Yashin, A; Tan, Q; Yang, Z; Bolund, L; Ming, Q; Yang, H; Min, J; Willcox, DC; Willcox, BJ; Gu, J; Hauser, E; Tian, X; Vaupel, JW
On the basis of the genotypic/phenotypic data from Chinese Longitudinal Healthy Longevity Survey (CLHLS) and Cox proportional hazard model, the present study demonstrates that interactions between carrying FOXO1A-209 genotypes and tea drinking are significantly associated with lower risk of mortality at advanced ages. Such a significant association is replicated in two independent Han Chinese CLHLS cohorts (p = 0.028-0.048 in the discovery and replication cohorts, and p = 0.003-0.016 in the combined dataset). We found the associations between tea drinking and reduced mortality are much stronger among carriers of the FOXO1A-209 genotype compared to non-carriers, and drinking tea is associated with a reversal of the negative effects of carrying FOXO1A-209 minor alleles, that is, from a substantially increased mortality risk to substantially reduced mortality risk at advanced ages. The impacts are considerably stronger among those who carry two copies of the FOXO1A minor allele than those who carry one copy. On the basis of previously reported experiments on human cell models concerning FOXO1A-by-tea-compounds interactions, we speculate that results in the present study indicate that tea drinking may inhibit FOXO1A-209 gene expression and its biological functions, which reduces the negative impacts of FOXO1A-209 gene on longevity (as reported in the literature) and offers protection against mortality risk at oldest-old ages. Our empirical findings imply that the health outcomes of particular nutritional interventions, including tea drinking, may, in part, depend upon individual genetic profiles, and the research on the effects of nutrigenomics interactions could potentially be useful for rejuvenation therapies in the clinic or associated healthy aging intervention programs.
Open Access
Loss of deep roots limits biogenic agents of soil development that are only partially restored by decades of forest regeneration
(Elementa, 2018-01-01) Billings, SA; Hirmas, D; Sullivan, PL; Lehmeier, CA; Bagchi, S; Min, K; Brecheisen, Z; Hauser, E; Stair, R; Flournoy, R; De Richter, DB
© 2018 The Author(s). Roots and associated microbes generate acid-forming CO2 and organic acids and accelerate mineral weathering deep within Earth's critical zone (CZ). At the Calhoun CZ Observatory in the USA's Southern Piedmont, we tested the hypothesis that deforestation-induced deep root losses reduce root- and microbially-mediated weathering agents well below maximum root density (to 5 m), and impart land-use legacies even after ∼70 y of forest regeneration. In forested plots, root density declined with depth to 200 cm; in cultivated plots, roots approached zero at depths >70 cm. Below 70 cm, root densities in old-growth forests averaged 2.1 times those in regenerating forests. Modeled root distributions suggest declines in density with depth were steepest in agricultural plots, and least severe in old-growth forests. Root densities influenced biogeochemical environments in multiple ways. Microbial community composition varied with land use from surface horizons to 500 cm; relative abundance of root-associated bacteria was greater in old-growth soils than in regenerating forests, particularly at 100-150 cm. At 500 cm in old-growth forests, salt-extractable organic C (EOC), an organic acid proxy, was 8.8 and 12.5 times that in regenerating forest and agricultural soils, respectively. The proportion of soil organic carbon comprised of EOC was greater in old-growth forests (20.0 ± 2.6%) compared to regenerating forests (2.1 ± 1.1) and agricultural soils (1.9 ± 0.9%). Between 20 and 500 cm, [EOC] increased more with root density in old-growth relative to regenerating forests. At 300 cm, in situ growing season [CO2] was significantly greater in old-growth forests relative to regenerating forests and cultivated plots; at 300 and 500 cm, cultivated soil [CO2] was significantly lower than in forests. Microbially-respired δ13C-CO2 suggests that microbes may rely partially on crop residue even after ∼70 y of forest regeneration. We assert that forest conversion to frequently disturbed ecosystems limits deep roots and reduces biotic generation of downward-propagating weathering agents.
Open Access
Persistent anthropogenic legacies structure depth dependence of regenerating rooting systems and their functions
(Biogeochemistry, 2020-02-01) Hauser, E; Richter, DD; Markewitz, D; Brecheisen, Z; Billings, SA
© 2020, Springer Nature Switzerland AG. Biotically-mediated weathering helps to shape Earth’s surface. For example, plants expend carbon (C) to mobilize nutrients in forms whose relative abundances vary with depth. It thus is likely that trees’ nutrient acquisition strategies—their investment in rooting systems and exudates—may function differently following disturbance-induced changes in depth of rooting zones and soil nutrient stocks. These changes may persist across centuries. We test the hypothesis that plant C allocation for nutrient acquisition is depth dependent as a function of rooting system development and relative abundances of organic vs. mineral nutrient stocks. We further posit that patterns of belowground C allocation to nutrient acquisition reveal anthropogenic signatures through many decades of forest regeneration. To test this idea, we examined fine root abundances and rooting system C in organic acid exudates and exo-enzymes in tandem with depth distributions of organically- and mineral-bound P stocks. Our design permitted us to estimate C tradeoffs between organic vs. mineral nutrient benefits in paired forests with many similar aboveground traits but different ages: post-agricultural mixed-pine forests and older reference hardwoods. Fine roots were more abundant throughout the upper 2 m in reference forest soils than in regenerating stands. Rooting systems in all forests exhibited depth-dependent C allocations to nutrient acquisition reflecting relative abundances of organic vs. mineral bound P stocks. Further, organic vs. mineral stocks underwent redistribution with historic land use, producing distinct ecosystem nutritional economies. In reference forests, rooting systems are allocating C to relatively deep fine roots and low-C exudation strategies that can increase mobility of mineral-bound P stocks. Regenerating forests exhibit relatively shallower fine root distributions and more diverse exudation strategies reflecting more variable nutrient stocks. We observed these disparities in rooting systems’ depth and nutritional mechanisms even though the regenerating forests have attained aboveground biomass stocks similar to those in reference hardwood forests. These distinctions offer plausible belowground mechanisms for observations of continued C sink strength in relatively old forests, and have implications for soil C fates and soil development on timescales relevant to human lifetimes. As such, depth-dependent nutrient returns on plant C investments represent a subtle but consequential signal of the Anthropocene.