Conversion to soy on the Amazonian agricultural frontier increases streamflow without affecting stormflow dynamics

Large‐scale soy agriculture in the southern Brazilian Amazon now rivals deforestation for pasture as the region's predominant form of land use change. Such landscape‐level change can have substantial consequences for local and regional hydrology, but these effects remain relatively unstudied in this ecologically and economically important region. We examined how the conversion to soy agriculture influences water balances and stormflows using stream discharge (water yields) and the timing of discharge (stream hydrographs) in small (2.5–13.5 km²) forested and soy headwater watersheds in the Upper Xingu Watershed in the state of Mato Grosso, Brazil. We monitored water yield for 1 year in three forested and four soy watersheds. Mean daily water yields were approximately four times higher in soy than forested watersheds, and soy watersheds showed greater seasonal variability in discharge. The contribution of stormflows to annual streamflow in all streams was low (<13% of annual streamflow), and the contribution of stormflow to streamflow did not differ between land uses. If the increases in water yield observed in this study are typical, landscape‐scale conversion to soy substantially alters water‐balance, potentially altering the regional hydrology over large areas of the southern Amazon.     

Mapping QTLs for tissue culture response in soybean (Glycine max (L.) Merr.)

Hempseed is rich in polyunsaturated fatty acids (PUFAs), which have potential as therapeutic compounds for the treatment of neurodegenerative and cardiovascular disease. However, the effect of hempseed meal (HSM) intake on the animal models of these diseases has yet to be elucidated. In this study, we assessed the effects of the intake of HSM and PUFAs on oxidative stress, cytotoxicity and neurological phenotypes, and cholesterol uptake, using Drosophila models. HSM intake was shown to reduce H₂O₂ toxicity markedly, indicating that HSM exerts a profound antioxidant effect. Meanwhile, intake of HSM, as well as linoleic or linolenic acids (major PUFA components of HSM) was shown to ameliorate Aβ42-induced eye degeneration, thus suggesting that these compounds exert a protective effect against Aβ42 cytotoxicity. On the contrary, locomotion and longevity in the Parkinson’s disease model and eye degeneration in the Huntington’s disease model were unaffected by HSM feeding. Additionally, intake of HSM or linoleic acid was shown to reduce cholesterol uptake significantly. Moreover, linoleic acid intake has been shown to delay pupariation, and cholesterol feeding rescued the linoleic acid-induced larval growth delay, thereby indicating that linoleic acid acts antagonistically with cholesterol during larval growth. In conclusion, our results indicate that HSM and linoleic acid exert inhibitory effects on both Aβ42 cytotoxicity and cholesterol uptake, and are potential candidates for the treatment of Alzheimer’s disease and cardiovascular disease.     

Phospholipid and triacylglycerol profiles modified by PLD suppression in soybean seed

Phospholipase D (PLD) is capable of hydrolyzing membrane phospholipids, producing phosphatidic acid. To alter phospholipid profiles in soybean seed, we attenuated PLD enzyme activity by an RNA interference construct using the partial sequence from a soybean PLDα gene. Two transgenic soybean lines were established by particle inflow gun (PIG) bombardment by co‐bombarding with pSPLDi and pHG1 vectors. The lines were evaluated for the presence and expression of transgenes thoroughly through the T₄ generation. PLD‐suppressed soybean lines were characterized by decreased PLDα enzyme activity and decreased PLDα protein both during seed development and in mature seeds. There was no change in total phospholipid amount; however, the PLD‐attenuated transgenic soybean seed had higher levels of di18 : 2 (dilinoleoyl)‐phosphatidylcholine (PC) and ‐phosphatidylethanolamine (PE) in seeds than the non‐transgenic lines. The increased polyunsaturation was at the expense of PC and PE species containing monounsaturated or saturated fatty acids. In addition to increased unsaturation in the phospholipids, there was a decrease in unsaturation of the triacylglycerol (TAG) fraction of the soybean seeds. Considering recent evidence for the notion that desaturation of fatty acids occurs in the PC fraction and that the PC → DAG (diacylglycerol) → TAG pathway is the major route of TAG biosynthesis in developing soybean seed, the current data suggest that PLDα suppression slows the conversion of PC to TAG. This would be consistent with PLD playing a positive role in that conversion. The data indicate that soybean PLD attenuation is a potentially useful approach to altering properties of edible and industrial soybean lecithin.     

Production of monoclonal antibodies with a controlled N‐glycosylation pattern in seeds of Arabidopsis thaliana

Seed‐specific expression is an appealing alternative technology for the production of recombinant proteins in transgenic plants. Whereas attractive yields of recombinant proteins have been achieved by this method, little attention has been paid to the intracellular deposition and the quality of such products. Here, we demonstrate a comparative study of two antiviral monoclonal antibodies (mAbs) (HA78 against Hepatitis A virus; 2G12 against HIV) expressed in seeds of Arabidopsis wild‐type (wt) plants and glycosylation mutants lacking plant specific N‐glycan residues. We demonstrate that 2G12 is produced with complex N‐glycans at great uniformity in the wt as well as in the glycosylation mutant, carrying a single dominant glycosylation species, GnGnXF and GnGn, respectively. HA78 in contrast, contains additionally to complex N‐glycans significant amounts of oligo‐mannosidic structures, which are typical for endoplasmic reticulum (ER)‐retained proteins. A detailed subcellular localization study demonstrated the deposition of both antibodies virtually exclusively in the extracellular space, illustrating their efficient secretion. In addition, although a KDEL‐tagged version of 2G12 exhibited an ER‐typical N‐glycosylation pattern, it was surprisingly detected in protein storage vacuoles. The different antibody variants showed different levels of degradation with hardly any degradation products detectable for HA78 carrying GnGnXF glycans. Finally, we demonstrate functional integrity of the HA78 and 2G12 glycoforms using viral inhibition assays. Our data therefore demonstrate the usability of transgenic seeds for the generation of mAbs with a controlled N‐glycosylation pattern, thus expanding the possibilities for the production of optimally glycosylated proteins with enhanced biological activities for the use as human therapeutics.     

放射性粒子125I联合TACE治疗兔VX2肝肿瘤的实验研究

目的:通过研究不同活度的125I粒子以及联合TACE治疗兔VX2肝移植癌的疗效及其病理基础,探讨125I粒子组织间植入治疗肝癌的有效性。方法:建立兔VX2肝癌模型。60只肝癌模型兔随机分成5组,对照组(A组)植入空白剂量(0mCi)125I粒子,B组植入1.0mCi125I粒子,C组植入0.7mCi125I粒子,D组植入0.4mCi125I粒子,E组植入0.7mCi125I粒子+TACE。观察植入前后各组肿瘤体积并计算抑瘤率,切除肿瘤组织及周围正常组织进行常规病理检查。结果:各治疗组肿瘤大小在治疗前后比较具有统计学差异(P<0.01),均小于同期对照组(A组)(P<0.01)。在不同观察时期抑瘤率差别均有统计学意义(P<0.05),各个组间抑瘤率差异在治疗后2周最为明显(P<0.01),但均高于D组(P<0.01)。治疗后6周病理提示D组部分组织内仍可见少量肿瘤细胞,而其余各治疗组均未见明显的肿瘤细胞残存,B组对周围肝组织损伤较大,C组、E组适中。总体疗效E组优于其余各治疗组。结论:125I粒子联合TACE治疗肝癌效果明显优于单一的治疗方案,是肝癌目前较为理想的治疗方案,其中单个粒子活度以0.7mCi左右较为适宜。     

Bacterial blight pathogen concentration in cotton seeds; its role in seed quality parameters of fuzzy and acid delinted seeds

Abstract

The adverse effects of increasing concentration of Xanthomonas axonopodis pv. malvacearum on cotton seed quality parameters, seedling dry weight and on defense-related enzyme, Phenylalanine Ammonia Lyase (PAL) were studied. Different concentrations of pathogen (1×10² to 1×10⁸ CFU/ml) were treated on both fuzzy and acid delinted seeds and subjected to the standard blotter method to study the effect of the pathogen on seed quality parameters. The seedling symptom test following the roll towel method, the modified germination test to study the blight incidence and the field emergence test were carried out to discover the field planting value and disease incidence under laboratory and field conditions. From these experiments, it was found that the decrease in the seed quality parameters like seed germination, seedling vigour, and the dry weight of seedlings when X. axonopodis pv. malvacearum concentration was increased. Whereas the bacterial blight incidence increased with an increase in pathogen concentration, in both greenhouse and field conditions. Phenylalanine ammonia lyase activity was found to increase along with the pathogen concentrations, but total phenol content decreased as pathogen concentration increased. The effect of X. axonopodis pv. malvacearum load on seed quality parameters, PAL enzyme activity of fuzzy and acid delinted cotton seeds are discussed in the present study.     

Prevalence and control of wheat (Triticum aestivum L.) seed borne fungi in farmer-saved seeds

High incidence of diseases associated with the use of seeds saved from previous harvests as desire of maintaining local varieties with special attributes is of increased concern in wheat industry worldwide. Prevalent of seed-borne fungi in farmer-saved seeds and seed dressing fungicides to prevent infection from seeds to seedlings was studied in Northern Tanzania. One hundred and thirty five untreated farmer-saved seed lots were collected randomly from farmers. Alternaria alternata, Bipolaris sorokiniana, Drechslera tritici, Fusarium graminearum, Fusarium moniliforme, Aspergillus flavus, Cladosporium sphaerospermum, Epicoccum purpurascens, Pyricularia oryzae and Penicillium corylophilum were fungi isolated in farmer-saved seeds. Mean seed infection was 29% causing average grain yield loss of 1.2 mt/ha^?1. Seed dressing with Metalaxy plus (Methyl carboxaitide), Mancozeb (Manganase-zinc salt) and Baytan (Chlorophenoxy ethanol) increased seed germination by 14, 13 and 17%, respectively, and grain yield by 28, 20 and 18%, respectively. Farmer-saved seeds were heavily infected by fungi with low grain yield performance.     

Molecular characterization of Rhizoctonia solani isolates the incitant of soybean root rot

Rhizoctonia solani isolates used in this investigation were identified as anastomosis-4 (AG-40), collected from different localities from Assiut governorate in Egypt. Pathogenicity test of seven isolates of R. solani was evaluated on soybean Giza 111 cultivar under greenhouse conditions. All tested isolates were able to infect soybean plants causing root rot with different degrees of severities, isolate No. 1, 2 and 3 showed significantly highest root rot severity, while isolate No. 5 gave the lowest percentage of root rot rating. The sodium dodecyl sulphate polyacrylamide gel electrophoresis patterns were used to compare three isolates of R. solani. There are no variations among R. solani isolates except a few exceptions according to their protein patterns. DNA markers obtained from all isolates showed genetic similarity among different isolates obtained from different geographical regions barring few exceptions. Correlation between DNA patterns of R. solani isolates and their virulence was detected, but no correlation with anastomosis groups (AG).     

Genetic diversity of non-pathogenic Clavibacter strains isolated from tomato seeds

Clavibacter michiganensis subsp. michiganensis (Cmm) is a seed-transmitted, quarantine pathogen which causes bacterial wilt and canker of tomato. Despite efforts to prevent seed contamination, new introductions are regularly detected, associated with new regions of tomato seed production. It seems as if the expanding diversity of Cmm also challenges the limited host range.