BackgroundGlyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a central enzyme in glycolysi, we performed genome-wide identification of GAPDH genes in wheat and analyzed their structural characteristics and expression patterns under abiotic stress in wheat.ResultsA total of 22 GAPDH genes were identified in wheat cv. Chinese spring; the phylogenetic and structure analysis showed that these GAPDH genes could be divided into four distinct subfamilies. The expression profiles of GAPDH genes showed tissue specificity all over plant development stages. The qRT-PCR results revealed that wheat GAPDHs were involved in several abiotic stress response.ConclusionsWheat carried 22 GAPDH genes, representing four types of plant GAPDHs (gapA/B, gapC, gapCp and gapN). Whole genome duplication and segmental duplication might account for the expansion of wheat GAPDHs. Expression analysis implied that GAPDHs play roles in plants abiotic stress tolerance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2527-3) contains supplementary material, which is available to authorized users.

On the Loess Plateau of China, deep rooted, fast-growing species, such as caragana (Caragana korshinskii Kom.), are widely used in afforestation projects. High planting densities and soil water consumption has led to soil desiccation and degradation. We conducted a two-year (2002 to 2003) field experiment assessing the effect of caragana planting density on plant growth and hydrological processes at the Shanghuang Eco-Experimental station. Caragana canopy interception, surface runoff, soil loss, and changes in plant growth and soil water content were determined for five planting densities ranging from 16 to 87 shrubs 100 m -2 (1,076 ft -2 ). Increases in the caragana canopy within the growing season and greater planting densities resulted in higher canopy interception and in lower runoff and soil loss. The soil water carrying capacity for the caragana amounted to 72 shrubs100 m -2 when rainfall approaches the long-term average. A sustainable, managed planting density is required that will balance soil water losses due to runoff, the plant's water requirements, and the water supply. In cases where soil desiccation has already occurred, conservation management plans should attempt to recharge the soil water in order to reverse soil degradation.

Non-native plantation can effectively conserve soil and water and improve ecological environment，but soil desiccation occurs and then changes to severe desiccation in most forest and grass lands of water-limited regions, which causes soil degradation, vegetation decline and crop failure, so it is necessary to regulate the changed relationship between plant growth and soil water. However, there is a lack of a universally accepted theory to provide guidance of sustainable use of soil water resources and sustainable management of forest and sustainable produce of crop in such regions. The theory of regulating the relationship between plant growth and soil water in water-limited regions includes the Soil Water Resources Use Limit by Plant ( SWRULP) and Soil Water Carrying Capacity for Vegetation(SWCCV). The SWCCV is the population in a plant population or density of indicator plants in a plant community when the soil water supply is equal to soil water consumption in the root zone and a given time, and changes with plant community type, location and time. The degree of coverage, productivity and benefits of a plant community when population quantity of an indicator plant equals SWCCV should be the theoretical basis for ensuring sustainable use of soil water resources and sustainable development of forest.

The maximum infiltration depth and soil water supply must be evaluated in order to estimate the soil water resource use limit by plants and soil water carrying capacity for vegetation, and realize the sustainable use of soil water resources. However, there is no non-destructive method to estimate maximum infiltration depth and soil water supply. We conducted a simulated infiltration experiment and a long-term fixed-position investigation in situ in artificial Caragana shrubland at the Guyuan Eco-experimental Station in the semiarid Loess Plateau. The results showed that infiltration depth for one rain event was equal to the distance from the surface to the crossover point between the two soil water distribution curves with soil depth before a rain event and after the rain event. The soil water supply for one rainfall event was the difference in the soil water resources in the soil layers from maximum infiltration depth that occurred after a long period, and could be estimated by a series of two-curve methods. A maximum infiltration depth of 2.9 m occurred in the artificial Caragana shrubland. The results provide a foundation for controlling soil degradation and sustainable use of soil water resources in water-limited regions.

BackgroundThis study aimed to assess ethnic differences in health-related quality of life (HRQoL) among the rural elderly, and to examine the influence of ethnic culture, residential segregation and socioeconomic development on HRQoL.MethodsA total of 6,511 rural elderly aged 60 years and older from 5,541 households in 116 villages across eight ethnic groups in Guangxi Zhuang Autonomous region were selected and assessed for HRQoL. The EQ-5D index values were calculated based on the Chinese Time Trade-Off values set. The EQ-5D descriptive system scores, visual analogue scale scores, and index values were described by ethnic group. The EQ-5D index was modeled against ethnic culture, residential segregation and socioeconomic development using villages as random effects.ResultsThe median (IQR) of HRQoL among all the ethnic groups was 0.88 (0.80, 0.96). Pain/discomfort was the most prevalent problem, followed by anxiety/depression. After controlling for sociodemographic characteristics, a significant difference in HRQoL among ethnic groups persisted, but this was not true for residential segregation.ConclusionSocial welfare and health policies designed to improve the health of the rural elderly should focus more on older, female, less-educated, Yao minority individuals as well as lower-income households.