Anti-inflammatory and Analgesic Effects of Extract from Roots and Leaves of Citrullus lanatus

Objective To study anti-inflammatory and analgesic effects of extract from the roots and leaves of Citrullus lanatus and assess their acute toxicity in animals. Methods The mouse model with ear edema induced by xylene and the rat model with paw edema or granuloma by carrageenin or cotton pellet were used for anti-inflammatory effects of the extract. Effects of the extract on analgesia was tested respectively by measuring the latency of mice licking hind foot from hot plates and by counting the times of body twisting in response to acetic acid. The acute toxicity of the extract was determined with the method of Bliss. Results The extract significantly inhibited the ear edema, granuloma hyperplasia, and paw edema. It significantly lifted the pain threshold on mouse hot-plate responses and reduced their writhing times. During the 7 d observation period in its acute toxicity assay, no apparent toxic reaction was shown and all mice survived at a dose of 87 g extract per kg body weight. Conclusion The extract could protecte mice/rates from inflammation and analgesia, and may be safe as an orally administered natural product for humans.

Suboptimal Temperature Acclimation Enhances Chilling Tolerance by Improving Photosynthetic Adaptability and Osmoregulation Ability in Watermelon

The temperature drop of plants from the optimal requirements can increase tolerance to severe chilling stress. Photosynthesis and osmoregulators were analyzed during chilling stress to explore the adaptation mechanisms that underlie the induction of chilling tolerance in response to suboptimal temperature. The relationships of these processes to suboptimal temperature acclimation in watermelon were then determined.Suboptimal temperature-acclimated watermelon plants demonstrated tolerance during chilling stress, as indicated by the decreased electrolyte leakage and malondialdehyde accumulation compared with those non-acclimated watermelon plants. Chilling-induced photoinhibition and reduction in CO2 assimilation rate were alleviated after suboptimal temperature acclimation. The xanthophyll cycle level was enhanced by improving thermal dissipation ability and avoiding light damage. Consequently, the chilling tolerance of suboptimal temperature-acclimated watermelon plants was enhanced. The osmoregulation ability induced by suboptimal temperature acclimation protected watermelon plants against chilling injury because of the accumulation of small molecular substances, such as soluble sugar and proline. The protein levels of Rubisco activase(ClRCA) and the gene expression of the Benson–Calvin cycle simultaneously increased in suboptimal temperature-acclimated watermelon plants during chilling stress. Chilling tolerance in watermelon plants induced by suboptimal temperature acclimation is associated with enhanced photosynthetic adaptability and osmoregulation ability.

Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

Watermelon peel residues were used to produce a new biochar by dehydration method.The new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI)ions from aqueous solution has been investigated.Three biochars,Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,were made from watermelon peel via dehydration with 50%sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_(2) or Triethylenetetramine(TETA)to give Melon-BO-TETA.The prepared biochars were characterized by BET,BJH,SEM,FT-IR,TGA,DSC and EDAX analyses.The highest removal percentage of Cr(VI)ions was 69%for Melon-B,98%for Melon-BO-NH_(2) and 99%for Melon-BO-TETA biochars of 100 mg·L^(−1) Cr(VI)ions initial concentration and 1.0 g·L^(−1) adsorbents dose.The unmodified biochar(Melon-B)and modified biochars(Melon-BO-NH_(2) and Melon-BO-TETA)had maximum adsorption capacities(Q_(m))of 72.46,123.46,and 333.33 mg·g^(−1),respectively.The amination of biochar reduced the pore size of modified biochar,whereas the surface area was enhanced.The obtained data of isotherm models were tested using different error function equations.The Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,respectively.The adsorption rate was primarily controlled by pseudo-second–order rate model.Conclusively,the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption process.The adsorption for the Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.

武汉市设施西瓜种植土壤健康评价指标初步构建

对武汉市主要农业生产区设施西瓜[Citrullus lanatus(Thunb.)Matsum.&Nakai]土壤(0~20 cm)和农产品进行取样,并检测土壤理化指标和微生物数量及农产品品质指标。结果表明,研究区域内土壤酸碱度空间变异较大,pH在4.91~7.16;土壤有机质含量变化范围在9.43~30.75 g/kg;种植土壤的硝态氮含量非常丰富,有效磷和速效钾含量均处于较高水平;土壤容重和紧实度较为接近,土壤田间持水量因种植方式的不同存在一定差异;设施栽培土壤中真菌数量变化不大,而细菌和放线菌数量浮动较明显。通过主成分分析方法对武汉市设施西瓜土壤的健康评价指标进行筛选,初步选择了pH、速效钾含量、有机质含量、硝态氮含量、田间持水量和细菌含量等指标作为评价指标。

鄂州市土壤墒情变化规律与西瓜种植区土壤水分评价指标

为定量评估鄂州市西瓜(Citrullus lanatus L.)种植区土壤含水量和科学管控水分,利用鄂州市2015—2020年的气象资料及墒情监测数据,分析了鄂州市土壤墒情变化规律,初步建立西瓜土壤墒情评价指标体系,并选取日平均气温、7 d平均气温、日降水量、7 d累积降水量、相对湿度、平均风速和日照时数7个气象因子进行主成分分析。结果表明,鄂州市表层土壤墒情受降水量、平均气温、日照时数影响较大,平均风速对土壤水分变化影响不大;主成分分析预报模型能较好地预报土壤水分,达到乙级预报标准,可用于预报作业。采用该评价指标体系,西瓜种植区可以在生长周期内适当调整水分的供给,促进植株的生长,提高果实品质,还能节约有限的水资源。

^(60)Co-γ射线辐射西瓜种子对叶片光合色素含量和气体交换参数的影响

以12个不同千粒重的西瓜(Citrullus lanatus)品种干种子为试验材料,设置6个^(60)Co-γ射线剂量辐射处理,研究不同辐射剂量对西瓜种子的影响,并通过大田试验观察辐射材料的性状表现(开花期及果实性状)。结果表明,西瓜种子经^(60)Co-γ射线辐射后,叶片中的叶绿素a、类胡萝卜素含量随着辐射剂量的增大总体呈先增加后减小的趋势,叶绿素b含量及气孔导度、净光合速率、蒸腾速率总体随着辐射剂量的增加而减少;^(60)Co-γ射线辐射对不同千粒重西瓜干种子的敏感性由强到弱依次为大种子、小种子、中等种子;不同基因型西瓜种子辐射敏感性由强到弱依次为杂交种子、常规种子。

^(60)Co-γ射线辐射对西瓜蔓长、分枝数及开花期的影响

为了探索^(60)Co-γ射线辐射对西瓜[Citrullus lanatus(Thunb.)Matsum.&Nakai]开花期及果实性状的影响,选取千粒重不同的12个西瓜品种种子为材料,设置6个剂量辐射处理,研究不同辐射剂量对西瓜种子开花期及果实性状的影响。研究发现,西瓜蔓长对^(60)Co-γ射线辐射敏感,开花期对其不敏感。400 Gy条件下西瓜分枝数与对照差异达显著水平;800 Gy条件下对西瓜开花期抑制作用明显;西瓜种子适宜的^(60)Co-γ射线辐射剂量为400~600 Gy,不同千粒重西瓜种子的蔓长对^(60)Co-γ射线辐射的敏感性为大种子>小种子>中等种子,分枝数对^(60)Co-γ射线辐射的敏感性为小种子强于中等种子,开花期对^(60)Co-γ射线辐射的敏感性为大种子>小种子=中等种子。

西瓜‘SM1’高效遗传转化体系的构建

为构建高效的西瓜再生和遗传转化体系,本研究以西瓜‘SM1’材料子叶节为外植体,研究不同激素配比对子叶节再生的影响。在此基础上,通过农杆菌介导法导入外源基因,研究潮霉素浓度、农杆菌侵染时间、共培养时间等因素对遗传转化效率的影响,建立遗传转化体系。结果表明,‘SM1’不定芽分化最佳培养基为MS+6-BA 1.0 mg/L+IAA 0.1 mg/L,不定芽分化率为91.7%。最优遗传转化组合为农杆菌侵染时间15 min,共培养3 d,之后进行选择培养。外植体不定芽分化潮霉素最适浓度为10 mg/L,最适生根培养基为1/2MS+6-BA 0.1 mg/L+NAA 0.01 mg/L。通过潮霉素筛选和PCR鉴定,获得12株阳性转化株系,转化率为6.5%。本研究建立了高效西瓜‘SM1’再生及遗传转化体系,为进一步开展基因功能研究及西瓜遗传改良提供了技术支撑。

基于极端个体GBS测序初步定位西瓜果形基因

西瓜果形是西瓜重要的外观性状,本研究利用以椭圆形品系K2和圆形品系L1为亲本的F2群体(351个个体),进行了西瓜果实宽、长及果形指数遗传和相关分析。结果表明果实宽度和果实长度呈典型正态分布,而果形指数分布上则出现双峰且圆果型∶椭圆果型接近于3∶1,说明在果形指数存在主效基因调控。果实宽度与果实长度、果实长度与果形指数呈极显著正相关,相关系数分别为0.427、0.669;果实宽度与果形指数呈极显著负相关,相关系数为-0.377。通过GBS(Genotyping-by-sequencing)分型技术对群体中果形指数大于1.4的10株个体和果形指数小于1.1的10株个体进行了基因分型,结合表型进行关联分析,将西瓜果形基因定位到了3号染色体的26.80~27.33 Mb区段内,并预测了14个候选基因。本研究结果为进一步精细定位果形基因打下基础。

西瓜种子不同发育时期内源激素含量变化

为揭示西瓜种子发育过程中内源激素调节机制,本研究以种子大小差异明显的‘LQ06’和‘XinA’西瓜栽培品种为研究材料,采用酶联免疫吸附测定法分析两者种子在不同发育时期内吲哚乙酸(IAA)、赤霉素(GA3)、脱落酸(ABA)和玉米素核苷(ZR)四种内源激素含量的动态变化规律。结果表明:在西瓜种子发育过程中,种子长度及百粒重均呈不典型的单S型曲线变化趋势;西瓜果实在开花后26 d就已基本达到成熟果实的大小,种子长度和百粒重在开花后8~12 d内迅速上升,12 d后种子长度不再发生剧烈变化,后期百粒重由于种子内部有机物质的积累还会继续上升。在开花后6 d时,两品系种子中IAA和ABA含量最高,在8~12 d内迅速上升,待22 d种子基本发育成熟后,略微下降至平稳状态;ZR和GA3则一直微量存在于种子整个发育过程中,且变化动态差异较大。ABA的含量在种子开花后的8~12 d内上升较快,并且IAA+GA3+ZT/ABA的值在6~12 d内呈下降趋势。本研究发现,种子发育是一个受多种激素互相协调共同调控的过程,种子的快速发育主要在开花后的8~12 d内发生,在该过程中种皮大小初步形成,并且高含量的ABA对于种子前期发育极为重要。研究结果为揭示西瓜种子发育过程中激素调节机制提供参考依据。

西瓜种子不同发育时期内源激素含量变化

为揭示西瓜种子发育过程中内源激素调节机制,本研究以种子大小差异明显的‘LQ06’和‘XinA’西瓜栽培品种为研究材料,采用酶联免疫吸附测定法分析两者种子在不同发育时期内吲哚乙酸(IAA)、赤霉素(GA3)、脱落酸(ABA)和玉米素核苷(ZR)四种内源激素含量的动态变化规律。结果表明:在西瓜种子发育过程中,种子长度及百粒重均呈不典型的单S型曲线变化趋势;西瓜果实在开花后26 d就已基本达到成熟果实的大小,种子长度和百粒重在开花后8~12 d内迅速上升,12 d后种子长度不再发生剧烈变化,后期百粒重由于种子内部有机物质的积累还会继续上升。在开花后6 d时,两品系种子中IAA和ABA含量最高,在8~12 d内迅速上升,待22 d种子基本发育成熟后,略微下降至平稳状态;ZR和GA3则一直微量存在于种子整个发育过程中,且变化动态差异较大。ABA的含量在种子开花后的8~12 d内上升较快,并且IAA+GA_(3)+ZR/ABA的值在6~12 d内呈下降趋势。本研究发现,种子发育是一个受多种激素互相协调共同调控的过程,种子的快速发育主要在开花后的8~12 d内发生,在该过程中种皮大小初步形成,并且高含量的ABA对于种子前期发育极为重要。研究结果为揭示西瓜种子发育过程中激素调节机制提供参考依据。

Mutation in the gene encoding 1-aminocyclopropane-1-carboxylate synthase 4 (CitACS4) led to andromonoecy in watermelon

Summary Although it has been reported previously that ethylene plays a critical role in sex determination in cucurbit species, how the andromonoecy that carries both the male and hermaphroditic flowers is determined in watermelon is still unknown. Here we showed that the watermelon gene 1-aminocyclopropane-1-carboxylate syn- thase 4 CCitACS4）, expressed specifically in carpel primor- dia, determines the andromonoecy in watermelon. Among four single nucleotide polymorphism （SNPs） and one lnDel identified in the coding region of CitACS4, the C364W mutation located in the conserved box 6 was co- segregated with andromonoecy. Enzymatic analyses showed that the C364W mutation caused a reduced activity in CitACS4. We believe that the reduced CitACS4 activity may hamper the programmed cell death in stamen primordia, leading to the formation of hermaphroditic flowers.

High-throughput Sequencing Reveals vsiRNAs Derived from Cucumber green mottle mosaic virus-infected Watermelon

Cucumber green mottle mosaic virus(CGMMV) is a member of the genus Tobamovirus, and is a serious pathogen of Cucurbitaceae crops. Virusderived small interfering RNAs(vsi RNAs), which are processed by Dicer-like and Argonaute proteins as well as RNA-dependent RNA polymerase,mediate the silencing of viral genomic RNA and host transcripts. To identify the CGMMV derived vsi RNAs and reveal interactions between CGMMV and watermelon host plant, deep sequencing technology was used to identify and characterize the vsi RNAs derived from CGMMV in infected watermelon plants in present study. A total of 10 801 368 vsi RNA reads representing 71 583 unique s RNAs were predicted in CGMMVinoculated watermelon plants. The CGMMV vsi RNAs were mostly 21 or 22 nt long. The majority of the CGMMV vsi RNAs(i.e., 91.7%) originated from the viral sense strand. Additionally, uracil was the predominant 5′-terminal base of vsi RNAs. Furthermore, the putative targets and functions of some of the CGMMV vsi RNAs were predicted and investigated. The results enhance our understanding of the interaction between CGMMV and the host watermelon and provide molecular basis for CGMMV resistance improvement in watermelon and other Cucurbitaceae crops.

西瓜减数分裂相关基因ClSPO11-1的互作蛋白筛选

减数分裂是有性生殖的关键过程。Ⅱ型拓扑异构酶SPO11是在植物减数分裂过程中起重要作用的一类酶,然而,该类酶在减数分裂过程中的具体分子作用机制目前尚有待鉴定。本研究以西瓜花蕾cDNA为模板,首次克隆获得西瓜拓扑异构酶基因ClSPO11-1的CDS全长1095 bp,编码394个氨基酸。为了进一步研究ClSPO11-1基因的功能及作用机制,本研究运用酵母双杂交技术,以ClSPO11-1作为诱饵蛋白,筛选西瓜混合cDNA表达文库,初步获得2个与ClSPO11-1互作的候选蛋白,分别是激酶相互作用家族蛋白(Cla014788)和酪氨酸磷酸酶(Cla008661)。本研究结果为进一步阐明ClSPO11-1在西瓜减数分裂中的具体分子机理提供了重要线索及依据。