Vegetation response to extreme climate events on the Mongolian Plateau from 2000 to 2010

Climate change has led to more frequent extreme winters (aka, dzud) and summer droughts on the Mongolian Plateau during the last decade. Among these events, the 2000–2002 combined summer drought–dzud and 2010 dzud were the most severe on vegetation. We examined the vegetation response to these extremes through the past decade across the Mongolian Plateau as compared to decadal means. We first assessed the severity and extent of drought using the Tropical Rainfall Measuring Mission (TRMM) precipitation data and the Palmer drought severity index (PDSI). We then examined the effects of drought by mapping anomalies in vegetation indices (EVI, EVI2) and land surface temperature derived from MODIS and AVHRR for the period of 2000–2010. We found that the standardized anomalies of vegetation indices exhibited positively skewed frequency distributions in dry years, which were more common for the desert biome than for grasslands. For the desert biome, the dry years (2000–2001, 2005 and 2009) were characterized by negative anomalies with peak values between �1.5 and �0.5 and were statistically different (P \u3c 0:001) from relatively wet years (2003, 2004 and 2007). Conversely, the frequency distributions of the dry years were not statistically different (p \u3c 0:001) from those of the relatively wet years for the grassland biome, showing that they were less responsive to drought and more resilient than the desert biome. We found that the desert biome is more vulnerable to drought than the grassland biome. Spatially averaged EVI was strongly correlated with the proportion of land area affected by drought (PDSI \u3c �1) in Inner Mongolia (IM) and Outer Mongolia (OM), showing that droughts substantially reduced vegetation activity. The correlation was stronger for the desert biome (R2 D 65 and 60, p \u3c 0:05) than for the IM grassland biome (R2 D 53, p \u3c 0:05). Our results showed significant differences in the responses to extreme climatic events (summer drought and dzud) between the desert and grassland biomes on the Plateau

Expression and characterization of recombinant human alpha-antitrypsin in transgenic rice seed

Human alpha-antitrypsin (AAT) is the most abundant circulating protease inhibitor in the human plasma. It is produced in the liver and exerts a primary physiological role as inhibitor for the neutrophil elastase in the lung. Individuals with one or several gene mutations in AAT causing reduction of the protein are related to lung, liver and pancreatic emphysema diseases and are treated lifelong with infusions of human plasma-derived AAT. Due to shortage of plasma and low expression levels of recombinant AAT in conventional gene expression systems, we explored the possibility to produce recombinant AAT in rice grains (Oryza sativa AAT, OsrAAT). An expression level of up to 2.24 g/kg brown rice and a final recovery of purified 0.366 g/kg OsrAAT has been obtained. OsrAAT has the same secondary structure and protease inhibitory activity as plasma-derived AAT (pAAT), but was highly heterogeneous with regard to glycan modifications. Thus 32.8% of OsrAAT were glycosylated and 67.2% were free of glycans as determined by MALDI-MS. Of the N-glycan structures 64.8% were vacuole-specific paucimannosidic molecules. Immune electron microscopy located OsrAAT in the endoplasmic reticulum lumen as precursor-accumulating (PAC)-like vesicle structures. The pharmacokinetic study indicated that the half-life of OsrAAT was prolonged, while the clearance rate was faster than that of pAAT in vivo. The results demonstrate that rice endosperm is a promising system to express this biopharmaceutical protein.Peer reviewed: YesNRC publication: Ye

Assessment of the immunogenicity of residual host cell protein impurities of OsrHSA

<div><p>Human serum albumin (HSA) is the most abundant protein in human plasma and is widely used at high doses for treating various diseases. Recombinant HSA is an alternative approach to plasma-derived HSA, providing increased safety and an unlimited supply. However, the safety of the residual host cell proteins (HCPs) co-purified with <i>Oryza sativa</i> HSA (OsrHSA) remains to be determined. An animal system was used to assess the immunogenicity of OsrHSA and its residual HCPs. Low immunogenicity and immunotoxicity of the residual HCPs at a dose of 25 μg/kg, equivalent to 25 times the clinical dosage of HSA, were observed. An anti-drug-antibody (ADA) analysis revealed that anti-HSA, anti-OsrHSA or anti-HCP antibodies developed with a low frequency in pHSA and OsrHSA treatments, but the titers were as low as 1.0–2.0. Furthermore, the titer and the incidence of the specific antibodies were not significantly different between the pHSA and OsrHSA groups, indicating that OsrHSA presents similar immunogenicity to that of pHSA. More importantly, no cytokines were stimulated after the administration of OsrHSA and the residual HCPs, suggesting that there was no risk of a cytokine storm. These results demonstrated that the residual HCPs from OsrHSA have low immunogenicity, indicating that the rice endosperm is one of the best hosts for plant molecular pharming.</p></div

Differentiating anthropogenic modification and precipitation-driven change on vegetation productivity on the Mongolian Plateau

Context: The Mongolian Plateau, comprising Inner Mongolia, China (IM) and Mongolia (MG) is undergoing consistent warming and accelerated land cover/land use change. Extensive modifications of water-limited regions can alter ecosystem function and processes; hence, it is important to differentiate the impacts of human activities and precipitation dynamics on vegetation productivity. Objectives: This study distinguished between human-induced and precipitation-driven changes in vegetation cover on the plateau across biome, vegetation type and administrative divisions. Methods: Non-parametric trend tests were applied to the time series of vegetation indices (VI) derived from MODIS and AVHRR and precipitation from TRMM and MERRA reanalysis data. VI residuals adjusted for rainfall were obtained from the regression between growing season maximum VI and monthly accumulated rainfall (June–August) and were used to detect human-induced trends in vegetation productivity during 1981–2010. The total livestock and population density trends were identified and then used to explain the VI residual trends. Results The slope of precipitation-adjusted EVI and EVI2 residuals were negatively correlated to total livestock density (R2 = 0.59 and 0.16, p \u3c 0.05) in MG and positively correlated with total population density (R2 = 0.31, p \u3c 0.05) in IM. The slope of precipitation-adjusted EVI and EVI2 residuals were also negatively correlated with goat density (R2 = 0.59 and 0.19, p \u3c 0.05) and sheep density in MG (R2 = 0.59 and 0.13, p \u3c 0.05) but not in IM. Conclusions Some administrative subdivisions in IM and MG showed decreasing trends in VI residuals. These trends could be attributed to increasing livestock or population density and changes in livestock herd composition. Other subdivisions showed increasing trends residuals, suggesting that the vegetation cover increase could be attributed to conservation efforts

The titers and incidence of antibodies against OsrHSA, pHSA and HCP.

<p>The titers and incidence of antibodies against OsrHSA, pHSA and HCP.</p

The incidence of pathological changes in target organs in different treatments at D15 and D42.

<p>The incidence of pathological changes in target organs in different treatments at D15 and D42.</p

The changes in T-lymphocyte subsets at D15 and D42.

<p>Panel A shows CD4+ T cells, panel B shows CD8+ T cells, and panel C shows the ratio of CD4+/CD8+ T cells. The data are presented as the mean ± SD (n = 5). "*" Indicates a statistically significant difference according to ANOVA and Dunnett’s test (<i>P</i>≤0.05).</p

The changes in CRP, CIC and C3 levels at D15 and D42.

<p>Panel A is CRP, panel B is CIC, and panel C is C3. Data are presented as the mean ± SD (n = 5); "*" Indicates a statistically significant difference according to ANOVA and Dunnett’s test (<i>P</i>≤0.05).</p

Proportion of vegetated area in the Mongolian Plateau covered by < − 1 standardized anomalies of EVI and EVI2 during June–July–August (JJA) in summer and January–February (JF) land surface temperature anomalies in winter

<p><b>Table 1.</b>  Proportion of vegetated area in the Mongolian Plateau covered by < − 1 standardized anomalies of EVI and EVI2 during June–July–August (JJA) in summer and January–February (JF) land surface temperature anomalies in winter. Summer droughts of 2001 and 2009 and <em>dzud</em> of 2010 are highlighted in bold. </p> <p><strong>Abstract</strong></p> <p>Climate change has led to more frequent extreme winters (aka, <em>dzud)</em> and summer droughts on the Mongolian Plateau during the last decade. Among these events, the 2000–2002 combined summer drought–<em>dzud</em> and 2010 <em>dzud</em> were the most severe on vegetation. We examined the vegetation response to these extremes through the past decade across the Mongolian Plateau as compared to decadal means. We first assessed the severity and extent of drought using the Tropical Rainfall Measuring Mission (TRMM) precipitation data and the Palmer drought severity index (PDSI). We then examined the effects of drought by mapping anomalies in vegetation indices (EVI, EVI2) and land surface temperature derived from MODIS and AVHRR for the period of 2000–2010. We found that the standardized anomalies of vegetation indices exhibited positively skewed frequency distributions in dry years, which were more common for the desert biome than for grasslands. For the desert biome, the dry years (2000–2001, 2005 and 2009) were characterized by negative anomalies with peak values between −1.5 and −0.5 and were statistically different (<em>P</em> < 0.001) from relatively wet years (2003, 2004 and 2007). Conversely, the frequency distributions of the dry years were not statistically different (<em>p</em> < 0.001) from those of the relatively wet years for the grassland biome, showing that they were less responsive to drought and more resilient than the desert biome. We found that the desert biome is more vulnerable to drought than the grassland biome. Spatially averaged EVI was strongly correlated with the proportion of land area affected by drought (PDSI <− 1) in Inner Mongolia (IM) and Outer Mongolia (OM), showing that droughts substantially reduced vegetation activity. The correlation was stronger for the desert biome (<em>R</em>² = 65 and 60, <em>p</em> < 0.05) than for the IM grassland biome (<em>R</em>² = 53, <em>p</em> < 0.05). Our results showed significant differences in the responses to extreme climatic events (summer drought and <em>dzud</em>) between the desert and grassland biomes on the Plateau.</p