Germination of peanut kernels to enhance resveratrol biosynthesis and prepare sprouts as a functional vegetable

Bioactive benefits of resveratrol in the diets have attracted extensive interests of the public. Peanut is one of the potent natural sources of resveratrol. In this study, germination of peanut kernels to enhance resveratrol biosynthesis and preparation of sprouts as a functional vegetable was conducted. When the rehydrated kernels of three peanut cultivars were germinated at 25 degrees C and relative humidity 95% in dark for 9 days, resveratrol contents increased significantly from the range of 2.3 to 4.5 microg/g up to the range of 11.7 to 25.7 mug/g depending upon peanut cultivar. In comparison with the sprout components, resveratrol contents were highest in the cotyledons, slightly lower in the roots, and not detected in the stems. When the sprouts were heated in boiling water for 2 min, resveratrol contents varied in a limited range. Methanol extracts of the freeze-dried sprouts exhibited potent 1,1-diphenyl-2-picryl-hydrazyl scavenging activity and antioxidative potency against linoleic acid oxidation. These activities increased with an increase of germination time. After 9 days of germination, total free amino acid, sucrose, and glucose contents increased significantly while crude protein contents decreased and the large sodium dodecyl sulfate polyacrylamide gel electrophoresis protein molecules of the kernels were extensively degraded. From a practical viewpoint, it is of potency to prepare peanut sprouts as a functional vegetable.     

机械脱壳时花生仁损伤特征及规律

为深入研究机械脱壳过程中花生仁损伤机理和规律,改进花生脱壳机的设计,以辽宁省花生主产地花生品种为对象,运用微型电子拉压试验机、体视显微系统,研究了花生仁外形特征、损伤特征与规律,并进行了不同品种花生仁、不同加载速率、不同受压部位的相关力学特性试验。研究结果表明：不同品种、不同受压部位的花生仁破碎力差异显著,四粒红和花育23在加载速率为10 mm/min时的正压和侧压下平均破碎力分别为106.2、96.6 N和79.8、58.3 N;加载速率不同时,花生仁的破碎变形量和最大破碎载荷都随着加载速率的增大而减小。     

花生根、茎中白藜芦醇含量影响因素

为了获得含白藜芦醇较多的花生根、茎作为提取白藜芦醇的原料。该文考察了华东不同地区、不同品种、不同采收时间以及采后存放、提取环境对花生根、茎中的白藜芦醇含量的影响。结果表明:白藜芦醇富集在花生根表皮,木质部含量较少;不同生长环境、不同品种对花生中白藜芦醇的含量影响较大;同一品种,采收时间越晚,白藜芦醇含量越高。采收后的花生根霉变会提高其中的白藜芦醇含量;花生中白藜芦醇在酸性条件下较为稳定,而碱性条件下易变性。采用合适品种的晚收花生根在酸性条件下提取可得到白藜芦醇含量较高的原料。     

花生植株白藜芦醇提取工艺优化

为了提高花生的综合利用价值,开发天然白藜芦醇新原料,对花生中的白藜芦醇提取工艺进行了研究。通过对花生叶、茎、根和壳中白藜芦醇含量的比较,选出含量最高的花生根为提取原料,并从5种提取方法中选出纤维素酶法作为花生根白藜芦醇的提取方法。通过单因素试验和正交试验对酶法提取花生根白藜芦醇酶解工艺进行了优化。结果表明:最佳的酶解条件为酶用量为1.6mg/g,酶解温度为45℃,酶解pH值为4.5,反应时间为60min,底物浓度为15%,在此条件下白藜芦醇的提取率是传统提取工艺的2倍。     

花生芽白藜芦醇大孔树脂纯化工艺及抑菌功效

为分离纯化花生芽中具有潜在抑菌活性的白藜芦醇化合物及研究其抑菌功效,提高花生的综合利用价值。该研究通过静态吸附-解吸试验,从16种不同型号大孔树脂中确定白藜芦醇较佳纯化树脂,并对其动态吸附-解吸条件优化,采用倍比稀释法、抑菌生长曲线及细胞膜通透性变化评价纯化物对鼠伤寒沙门氏菌的抑制作用。结果表明：LSA-40大孔树脂为花生芽白藜芦醇较佳纯化树脂,其吸附条件为：上样浓度120.00 μg/mL,速率1.00 mL/min,pH值4.2,上样量8.00 mL/g;解吸条件为：80%乙醇溶液,pH值6.6,流速1.00 mL/min,白藜芦醇纯度可达84.0%;利用紫外光谱、傅里叶红外光谱、超高效液相色谱串联质谱对纯化后样品进行鉴定分析,发现纯化物中主要成分为白藜芦醇及其衍生物;纯化物对鼠伤寒沙门氏菌抑制作用结果表明其最小抑菌浓度为250 μg/mL,在此浓度下可显著增加细胞膜通透性（P<0.01）,破坏细胞壁完整性,造成胞内蛋白质严重泄露,最终导致鼠伤寒沙门氏菌死亡。该研究可为花生资源综合深度利用及天然抑菌剂的开发提供一定理论参考。     

非生物胁迫下植物水通道蛋白的应答与调控

【目的】水分不仅是细胞中各类生命物质合成的必需底物,而且也参与植物体内的养分代谢和渗透平衡的调节。植物中水分的跨膜转运主要是由水通道蛋白(AQPs)所介导的,因此,无论是在植物整体水平还是细胞水平上,水分的吸收以及跨细胞膜系统的转运对于植物的生长发育都是至关重要的。近年来,水通道蛋白作为调节水分的吸收与转运的关键,已成为植物营养与分子生物学特别关注和研究的热点之一。本文从水通道蛋白的种类结构,底物特异性,基因表达特征和调控机制四个方面对水通道蛋白转运水分的机理和转运水分过程中对胁迫的响应机制进行了详细阐述;从水通道蛋白的水分运输和渗透调节功能及其养分运输功能两方面说明了水通道蛋白在植物生长过程中的生理作用;阐述了光照、干旱和低温与水通道蛋白功能之间的关系,明确了水通道蛋白通过表达量的增加或者降低来响应相应环境条件的变化。【主要机理】水通道蛋白通过保持一定结构及对底物运输的特异性来实现对水分的高效运输,通过调整基因的表达量和翻译后修饰等过程实现对水分的高效转运;同时,水通道蛋白可以通过水分的运输实现植物渗透平衡的调节,对部分小分子养分的吸收等功能更是实现了对植物生理和养分吸收的调节;另外,水通道蛋白不仅可以提高植物的抗旱、抗盐能力,对低温胁迫也有一定的响应,还可以与多类逆境胁迫蛋白发生相互作用,共同调节植物的水分和渗透平衡,提高植物应对逆境胁迫的能力,表明植物水通道蛋白对非生物胁迫下的应答机制有待于进一步探索,为植物水通道蛋白的应用研究提供科学的理论支持与材料支撑。     

Plant growth-promoting rhizobacteria-alleviators of abiotic stresses in soil: A review

With the continuous increase in human population,there is widespread usage of chemical fertilizers that are responsible for introducing abiotic stresses in agricultural crop lands.Abiotic stresses are major constraints for crop yield and global food security and therefore require an immediate response.The implementation of plant growth-promoting rhizobacteria(PGPR)into the agricultural production system can be a profitable alternative because of its efficiency in plant growth regulation and abiotic stress management.These bacteria have the potential to promote plant growth and to aid in the management of plant diseases and abiotic stresses in the soil through production of bacterial phytohormones and associated metabolites as well as through significant root morphological changes.These changes result in improved plant-water relations and nutritional status in plants and stimulate plants’defensive mechanisms to overcome unfavorable environmental conditions.Here,we describe the significance of plant-microbe interactions,highlighting the role of PGPR,bacterial phytohormones,and bacterial metabolites in relieving abiotic environmental stress in soil.Further research is necessary to gather in-depth knowledge on PGPR-associated mechanisms and plant-microbe interactions in order to pave a way for field-scale application of beneficial rhizobacteria,with the aim of building a healthy and sustainable agricultural system.Therefore,this review aims to emphasize the role of PGPR in growth promotion and management of abiotic soil stress with the goal of developing an eco-friendly and cost-effective strategy for future agricultural sustainability.     

Localized production of phytoalexins by peanut (Arachis hypogaea) kernels in response to invasion by Aspergillus species

Peanuts respond to fungal infection by synthesizing phytoalexins, most of which are antibiotic stilbenes. The mechanism and dynamics of phytoalexin formation in the peanut have not been studied. One of the most popular peanut cultivars in the southeastern United States, Georgia Green, was investigated for its ability to produce phytoalexins in response to infection by soil fungal strains. The experimental design allowed for study of phytoalexin production in peanut kernels layer-by-layer. The layers were dissected from different depths of the kernel starting from the infected area down to healthier tissues. Six peanut phytoalexins, trans-resveratrol, trans-arachidin-1, trans-arachidin-2, trans-arachidin-3, trans-3-isopentadienyl-4,3',5'-trihydroxystilbene, and SB-1, were detected in the kernel slices and quantitated. All of the fungal strains triggered phytoalexin production; however, the composition of phytoalexins varied significantly by layer. After incubation for 24 h, tissues remote from the infected area produced almost exclusively trans-resveratrol, whereas closer to the infected area tissues synthesized all six phytoalexins. In all of the experiments, after 48 h of fungal growth, deeper layers produced all tested phytoalexins. There was a significant difference in phytoalexin production elicited by some fungal isolates. No association was observed between phytoalexin production and toxigenic potential of fungal strains that elicited the production in mature peanut kernels.     

Role of methylotrophic bacteria in managing abiotic stresses for enhancing agricultural production

Abiotic stresses are a significant factor that considerably limits plant growth and productivity. Methylotrophs are an essential group of bacteria that utilize volatile carbon compounds, are prolific colonizers of different plant parts, and play a vital role in plant growth promotion(PGP) under stress conditions.Numerous rhizospheric and phyllosphere methylotrophs have been reported to exhibit PGP activities with superior stress-tolerating capacity against drought,heavy metal, salinity, high and...     

The role of potassium in alleviating detrimental effects of abiotic stresses in plants

Plants exposed to environmental stress factors, such as drought, chilling, high light intensity, heat, and nutrient limitations, suffer from oxidative damage catalyzed by reactive oxygen species (ROS), e.g., superoxide radical (O₂equation/tex2gif-sup-1.gif^–), hydrogen peroxide (H₂O₂) and hydroxyl radical (OHequation/tex2gif-sup-4.gif). Reactive O₂ species are known to be primarily responsible for impairment of cellular function and growth depression under stress conditions. In plants, ROS are predominantly produced during the photosynthetic electron transport and activation of membrane‐bound NAD(P)H oxidases. Increasing evidence suggests that improvement of potassium (K)‐nutritional status of plants can greatly lower the ROS production by reducing activity of NAD(P)H oxidases and maintaining photosynthetic electron transport. Potassium deficiency causes severe reduction in photosynthetic CO₂ fixation and impairment in partitioning and utilization of photosynthates. Such disturbances result in excess of photosynthetically produced electrons and thus stimulation of ROS production by intensified transfer of electrons to O₂. Recently, it was shown that there is an impressive increase in capacity of bean root cells to oxidize NADPH when exposed to K deficiency. An increase in NADPH oxidation was up to 8‐fold higher in plants with low K supply than in K‐sufficient plants. Accordingly, K deficiency also caused an increase in NADPH‐dependent O₂equation/tex2gif-sup-6.gif^– generation in root cells. The results indicate that increases in ROS production during both photosynthetic electron transport and NADPH‐oxidizing enzyme reactions may be involved in membrane damage and chlorophyll degradation in K‐deficient plants. In good agreement with this suggestion, increases in severity of K deficiency were associated with enhanced activity of enzymes involved in detoxification of H₂O₂ (ascorbate peroxidase) and utilization of H₂O₂ in oxidative processes (guaiacol peroxidase). Moreover, K‐deficient plants are highly light‐sensitive and very rapidly become chlorotic and necrotic when exposed to high light intensity. In view of the fact that ROS production by photosynthetic electron transport and NADPH oxidases is especially high when plants are exposed to environmental stress conditions, it seems reasonable to suggest that the improvement of K‐nutritional status of plants might be of great importance for the survival of crop plants under environmental stress conditions, such as drought, chilling, and high light intensity. Several examples are presented here emphasizing the roles of K in alleviating adverse effects of different abiotic stress factors on crop production.     

基于同心轴圆筒式电容传感器的花生仁水分无损检测技术

为了实现花生仁含水率的快速准确检测,设计了以MSP430单片机为控制芯片的花生仁含水率检测仪,利用圆筒式电容传感器、温度传感器和称质量传感器分别检测花生仁的电容、温度和容积密度,通过信号检测调理电路进行测量信号电容到频率的转换,单片机进行数据处理后计算出花生仁含水率,在液晶屏上显示检测结果,并将检测数据存储到内存卡中。进一步研究了含水率、温度和容积密度对频率的影响规律,建立了描述含水率与差频、温度的数学模型,并验证了基于电容法检测花生含水率的可行性和模型的可靠性。试验表明,在含水率6.4%~18.2%、温度10~40℃范围内,该检测仪的测量相对误差绝对值小于0.5%。该研究为快速无损检测花生仁含水率提供了参考。     

A modified chemical procedure for rapid determination of glucosamine and its application for estimation of mold growth in peanut kernels and koji.

One-step hydrolysis of chitin to release glucosamine for quantitation was achieved by combining a chitin-containing sample (10-200 mg of sample size) in a test tube with 1 mL of 10 M HCl followed by vacuum treatment for 10 min, incubation at 28 degrees C for 30 min, replenishment with 3 mL of deionized water, nitrogen flushing, screw capping, and heat treatment at 140 degrees C for 60 min. A phosphate buffer solution (pH 12.5, 0.2 M) was effective in pH stabilization and enhancing colorimetric determination of glucosamine content. When the modified procedure was applied to analyze glucosamine content in the mycelia of various molds, glucosamine content varied mainly depending on mold species. In estimations of mold growth of the uninoculated peanut kernels incubated under a humidified condition for 5 weeks, cooked rice and soybean inoculated with conidia of Aspergillus oryzae for koji preparation, logarithms of the internal mold populations and glucosamine contents both increased with increases of incubation time. The modified procedure provided a rapid and reliable estimation of mold growth in various substrates.     

Ecogeographic analysis of pea collection sites from China to determine potential sites with abiotic stresses

Pea (Pisum sativum L.) is grown widely throughout China and has undergone natural selection throughout its agricultural range over 2,000 years. Here we characterize collection site habitats to develop an understanding of the key selection pressures likely to be imposed by each environment to facilitate the investigation of specific adaptation. We characterized 240 collection sites of 529 pea landraces, across 25 provinces and 3 municipalities of China comprising the main pea cropping regions for climatic variables. Multivariate analyses showed that collection sites tended to cluster along geographic and abiotic stress clines. Spring sown sites and winter sown sites were clearly separated into 6 and 7 habitat type clusters respectively. In addition, regions which experience extreme abiotic stresses of frost, drought and high temperature in the reproductive period for pea landraces, were identified as targets for germplasm to be tested for respective tolerances to these stresses.     

外源钙缓解花生低温光合障碍的调控机制

[目的]北方春季低温冷害是限制花生生产的主要环境因素之一,钙素营养可提升花生耐冷性和光合碳同化作用,本研究进一步探究外源钙缓解花生低温光合障碍的调控机制.[方法]以花生品种'小白沙'为试验材料,在人工气候室内进行了盆栽培养试验.设常温喷清水对照(夜温/昼温为20℃/28℃,幼苗叶面喷清水);在低温胁迫(夜温/昼温为9℃...     

Oxidation of resveratrol catalyzed by soybean lipoxygenase

In this work the oxidative degradation of resveratrol catalyzed by lipoxygenase-1 (LOX-1) has been studied. The process has been characterized by spectroscopic and polarographic measurements. The oxidation of resveratrol was dependent on the concentration of resveratrol and the enzyme. When resveratrol was incubated in the presence of lipoxygenase at pH 9.0, the reaction displayed a k(M) value of 18.6 x 10(-)(6) M and a catalytic efficiency (k(cat)/k(M)) of 4.3 x 10(4) s(-)(1) M(-)(1). These values are close to those shown by the enzyme when linoleic acid is used as the substrate. The effect of lipoxygenase inhibitors on the lipoxygenase-catalyzed resveratrol oxidation was also evaluated. The rate of resveratrol oxidation was markedly decreased by the presence of NDGA in the incubation mixture. From HPLC measurements, it can be deduced that resveratrol is oxidatively decomposed to a complex mixture of products similar to those obtained when the molecule is oxidized by hydrogen peroxide.     

分步酶解制备花生短肽的研究

为了高效制备花生短肽,在花生蛋白Alcalase酶水解的研究基础上,进一步采用N120P酶水解花生蛋白并对各种影响因素进行了系统地研究;建立了短肽得率与各种影响因素的回归模型;确定出了N120P继续酶解花生蛋白Alcalase酶解物制备花生短肽的最佳工艺参数为pH值6.0,水解时间65 min,水解温度57℃,酶与底物比2061 U/g,。在此条件作用下,体系中短肽得率为89.01%,比Alcalase 单独酶解提高10.86个百分点;水解度为23.76%,平均肽链长度为4.21。经高效液相色谱测定,大部分水解产物的相对分子质量小于1000。     

Timing and rate of iron chelate application to correct chlorosis of peanut

The timing and rate of application of iron (Fe) chelates (seques‐trene 138 Fe) to correct Fe chlorosis of peanut grown on calcareous soils was studied for three seasons (1985–87) in seven experiments. It was found that the biological yield of peanut increased up to the highest rate of chelate used (8 g/m²). However, under the existing prices of the chelate and peanuts, application is financially untenable above 4 g/m². The time of chelate application should not be at sowing, but after the crop becomes chlorotic. Even though the yield differences between early application at branching, 25 to 30 days after emergence, and an application at anthesis, 45 to 50 days after emergence, was small, the trend in yield and size of nuts favored the earlier application. Therefore, it is recommended that the application of the Fe chelate be at the early stages of plant development, particularly in cases of severe chlorosis.     

Cadmium found in peanut (Arachis hypogaea L.) kernels mainly originates from root uptake rather than shell absorption from soil

Roots and shells are two potential organs through which peanut plants absorb cadium (Cd) from soils; however, the relative contributions of the two uptake pathways (root uptake and shell absorption) to kernel Cd accumulation and their translocation characteristics are poorly understood. In this study, the relative contributions of the two pathways to Cd accumulation in two peanut cultivars, Xianghua2008 (XH) and Yueyou43 (YY), were accurately assessed by labeling rooting and podding zone soils with ¹¹³Cd and ¹¹³Cd isotopes (0.3 mg kg^-1 dry soil), respectively, in a split-pot design. The results showed that approximately 96% of the Cd accumulated in the peanut kernels was derived from root uptake, while only 4% originated from shell absorption. Only 1% of the Cd accumulated in whole peanut plants was attributed to shell absorption, of which 41%–44% was retained in shells and 56%–59% was translocated to kernels. In contrast, the Cd absorbed by roots was efficiently translocated into all plant organs, of which 80%–84% was distributed in shoots. Although YY accumulated 1.3 times more Cd in whole plants than XH, the relative contributions of the two pathways to Cd accumulation in each plant organ were barely affected by peanut cultivars. Due to the strong retention effect of shells, shell-derived Cd was approximately 2 times higher than root-derived Cd in shells. These results would improve the understanding of Cd accumulation processes in peanut plants, revealing that the root uptake pathway contributes predominantly to the Cd concentration in peanut kernels, based on which strategies and technology for the reduction of Cd in peanut plants could be designed and developed.     

Physical characteristics of corn kernels as influenced by nitrogen fertilization

Abstract

Physical characteristics of corn (Zea mays L.) kernels influence end‐use. Agronomic practices including nitrogen (N) fertilization may influence kernel hardness. The objective of this study was to determine if com endosperm characteristics influence the effect of N fertilization on kernel hardness and breakage susceptibility. In 1988, six corn hybrids differing for endosperm were grown at two locations in Ohio and with two N rates (34 and 200 kg/ha). Kernels of the waxy hybrid were denser less susceptible to breakage than its near‐isogeneic normal counterpart. Soft kernels weighted less and were less dense than hard kernels, but these two hybrid classifications did not differ for breakage susceptibility. Hard kernels possessed a greater resistance to grinding than soft kernels. Increasing N fertilizer rate increased resistance to grinding and reduced susceptibility to breakage of both soft and hard endosperm types. Fertilization with N not only affects corn grain yield, but also affects physical characteristics that are important to end‐users.