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Abiotic stress caused by unsuitable environmental changes brings serious impacts on the growth and development of sorghum, resulting in significant loss in yield and quality every year. Phospholipase D is one of the key enzymes that catalyze the hydrolysis of phospholipids, and participates in plants response to abiotic stresses and phytohormones, whereas as the main producers of Phosphatidic acid (PA) signal, the detailed information about Phospholipase D associated (SbPLD) family in sorghum has been rarely reported. This study was performed to identify the PLD family gene in sorghum based on the latest genome annotation and to determine the expression of PLDs under abiotic stresses by qRT-PCR analysis. In this study, 13 PLD genes were identified in sorghum genome and further divided into 7 groups according to the phylogenetic analysis. All sorghum PLD family members harbored two conserved domains (HDK1&2) with catalytic activity, and most members contained a C2 domain. In ζ subfamily, C2 domain was replaced by PX and PH domain. The exon–intron structure of SbPLD genes within the same subfamily was highly conservative. The tissue specific expression analysis revealed different expression of SbPLD genes in various developmental stages. High level expression of SbPLDα3 was observed in almost all tissues, whereas SbPLDα4 was mainly expressed in roots. Under abiotic stress conditions, SbPLD genes responded actively to NaCl, ABA, drought (PEG) and cold (4 °C) treatment at the transcriptional level. The expression of SbPLDβ1 was significantly up-regulated, while the transcription of SbPLDζ was suppressed under various stress conditions. In addition, SbPLDβ1 and SbPLDδ2 were predicted to be the target genes of sbi-miR159 and sbi-miR167, respectively. This study will help to decipher the roles of PLDs in sorghum growth and abiotic stress responses. [ABSTRACT FROM AUTHOR]

Methylenetetrahydrofolatereductase (MTHFR) is an important enzyme involved in folate metabolism and DNA synthesis. Although a number of studies have examined the association of the MTHFR C677T and A1298C polymorphisms with susceptibility to rheumatoid arthritis (RA), the conclusions are controversial. A comprehensive literature search using PubMed, Embase, the Cochrane Library, CNKI and Wanfang databases was conducted for relevant studies on the association between MTHFR polymorphisms and RA risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed- and random-effect models. In total, 1854 cases and 1689 controls from 12 studies and 1525 cases and 1455 controls from 10 studies were included for the C677T and A1298C polymorphisms, respectively. Pooled results indicated that both C677T and A1298C polymorphisms were associated with RA susceptibility (C677T: TT vs. CC, OR = 1.31, 95% CI = 1.02-1.67, P = 0.032; TC vs. CC, OR = 1.32, 95% CI = 1.02-1.70, P = 0.032; TT + TC vs. CC, OR = 1.38, 95% CI = 1.07-1.78, P = 0.014; T vs. C, OR = 1.29, 95% CI = 1.06-1.57, P = 0.011; A1298C: CC vs. CA + AA: OR = 1.58, 95% CI = 1.20-2.06, P = 0.001). Further stratification based on ethnicity and geographic region indicated an association between the MTHFR C677T SNP and the risk of RA in Caucasian and patients in Africa. However, there is no evidence of significant association between A1298C polymorphism and RA risk in Caucasian or population in Africa. This meta-analysis indicates that MTHFR C677T and A1298C polymorphisms could be predictors of risk of RA and warrants validation in large and well-designed prospective studies. [ABSTRACT FROM AUTHOR]

It is well known that carbonates inhibit heavy metals transferring from soil to plants, yet the mechanism is poorly understood. Based on the Yangtze River delta area, we investigated bioaccumulation of Ni and Cd in winter wheat as affected by the presence of carbonates in soil. This study aimed to determine the mechanism through which soil carbonates restrict transport and plant uptake of heavy metals in the wheat cropping system. The results indicate that soil carbonates critically influenced heavy metal transfer from soil to plants and presented a tipping point. Wheat grains harvested from carbonates-depleted (due to severe leaching) soils showed Ni and Cd concentrations 2-3 times higher than those of the wheat grains from carbonates-containing soils. Correspondingly, the incidence of Ni or Cd contamination in the wheat grain samples increased by about three times. With the carbonate concentration >1% in soil, uptake and bioaccumulation of Ni and Cd by winter wheat was independent with the soil pH and carbonate content. The findings suggest that soil carbonates play a critical role in heavy metal transfer from soil to plants, implying that monitoring soil carbonate may be necessary in addition to soil pH for the evaluating soil quality and food safety. [ABSTRACT FROM AUTHOR]