亚麻籽粒中主要脂肪酸和蛋白质积累过程研究

以亚麻品种82(50)为材料,研究了亚麻籽粒中主要脂肪酸、蛋白质和糖积累的规律,结果表明:在亚麻籽粒发育成熟的过程中,棕榈酸、亚油酸含量持续下降,当籽粒完全成熟时降至最低;油酸和亚麻酸含量持续增加,当籽粒完全成熟时含量最高;硬脂酸在籽粒发育10～25d,其含量逐渐提高,以后逐渐下降。蛋白质随着籽粒发育成熟其含量持续提高,且蛋白质含量的提高主要发生在籽粒发育成熟的30d以前。总糖随籽粒发育成熟含量迅速下降,当种子完全成熟时降至最低。     

甘肃胡麻地方种质资源品质特性研究

对甘肃省116份胡麻地方品种的重要品质指标———粗脂肪、硬脂酸、棕榈酸、油酸、亚油酸、亚麻酸含量和碘值进行测定,并根据这些品质指标对供试品种进行聚类分析。结果显示:(1)供试品种粗脂肪含量平均值为37.48%,变异系数3.8%;硬脂酸、油酸含量平均值分别为5.32%和29.05%,变异系数分别为19.5%和11.6%;棕榈酸、亚麻酸、亚油酸含量平均值分别为5.9%、48.76%、10.95%,变异系数分别为8.4%、8%、8%;平均碘价175.60,变异系数2.76%;(2)聚类分析结果显示,116个品种聚为7大类,其中:b亚组群硬脂酸和油酸含量最高,而亚麻酸含量最低;d亚组群品种亚麻酸含量最高;e亚组群粗脂肪含量和碘价最高,油酸含量最低;f亚组群硬脂酸含量最低;g亚组群棕榈酸含量最高,碘价最低。     

不同种源山桐子果实脂肪酸组成变异分析

以采自11个种源的山桐子为材料,测定其果实脂肪酸的组成及其变异情况,结果表明：山桐子果实中不饱和脂肪酸含量较高,尤以亚油酸含量最高,11个种源的平均值为63．58％,且种源间差异显著,分宜、宜昌种源亚油酸相对含量明显高于其他9个种源;饱和脂肪酸以棕榈酸为主,11个种源山桐子果实棕榈酸差异显著,且以平武种源最高;其余脂肪酸含量均较低,变异幅度较大;种子中棕榈酸和棕榈烯酸含量明显高于果肉,而亚油酸、亚麻酸及硬脂酸含量明显低于果肉,油酸含量相近：果实不饱和脂肪酸含量依次为果肉〉全果〉种子,且变异系数及相对极差均较小,尤以果肉中最小;除硬脂酸外,山桐子果实中其他4种主要脂肪酸组分受海拔等地理环境的影响均较小。     

张掖市不同海拔地区5个胡麻品种品质特性比较分析

胡麻是甘肃省主要经济作物之一,海拔2 400 m以下的河西地区为甘肃高产区。为探明张掖不同海拔高度对胡麻品质特性的影响和不同胡麻品种的最佳种植区域,利用近红外品质分析仪,分析了张掖市4个不同海拔地区5个胡麻品种的常规品质指标、饱和脂肪酸和不饱和脂肪酸的含量差异。结果表明：蛋白质、粗脂肪、膳食纤维、棕榈酸、十七碳酸、豆蔻酸、二十四碳酸、油酸和α-亚麻酸含量的品种和海拔间互作效应极显著(P<0.01);山嵛酸、棕榈油酸、顺-11-二十碳一烯酸、亚油酸、γ-亚麻酸和顺-11,14,17-二十碳三烯酸含量随海拔高度不同,变化较小,稳定性好。在高含油量育种目标的基础上,兼顾高三大主要不饱和脂肪酸（α-亚麻酸、油酸和亚油酸）、低两大饱和脂肪酸（棕榈酸和硬脂酸）以及高蛋白质等其他品质育种目标的角度考虑,在张掖市甘州区、高台县巷道镇和民乐县三堡镇、民乐县六坝镇,最适宜种植的胡麻品种分别是5-9812-2-1、09-3-11、张亚2号。不同海拔高度对胡麻各品质指标具有重要影响,张掖市作为优质胡麻籽生产基地,可利用不同胡麻品种适宜种植区域不同,大力发展胡麻籽品质育种和胡麻籽综合开发等。     

不同含水量大葱种子贮藏后的脂肪代谢研究

将大葱种子干燥成1．8％-10．5％的不同含水量后。在50℃、35℃、20℃和-18℃条件下密闭贮存16个月。通过对棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸含量的研究,结果表明,随着贮存温度的升高,种子中棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸含量不断升高,但在20℃和-18℃的差异不明显。在50℃下含水量为1．8％～6．6％的种子。5种脂肪酸含量明显大于含水量为7．4％-10.5％的种子。     

沙棘种子高积累碳十八不饱和脂肪酸的多基因协同调控机制

为探讨沙棘种子油高积累碳十八不饱和脂肪酸的多基因协同作用机制,以近缘低油沙棘品系‘绥棘1号’和高油品系‘新俄3号’6个不同发育期的种子为材料,利用气相色谱飞行时间质谱法测定种子油脂肪酸组份,采用qRT-PCR方法分析不饱和脂肪酸合成积累相关基因KAR、FATB、Δ9 D、KASⅡ、SAD、FAD2、FAD3、FAD7和FAD8的表达模式,验证多基因表达对碳十八不饱和脂肪酸积累的影响。结果表明:(1)‘绥棘1号’和‘新俄3号’种子油均高积累碳十八不饱和脂肪酸,分别占总脂肪酸的87.71%和88.68%;种子发育期间,油酸相对含量一直呈上升趋势,亚油酸相对含量短时下降后上升趋稳,而亚麻酸相对含量则呈先上升后下降趋稳。(2)FATB基因下调表达协同Δ9 D基因低表达,使C16∶0-ACP转化为棕榈酸和棕榈油酸的代谢减弱,而KAR和KASⅡ基因的相对上调表达,促进了硬脂酸合成,为碳十八不饱和脂肪酸的合成积累了较多前体。(3)SAD基因的持续高表达催化硬脂酸去饱和为油酸,且持续上升的SAD/FATB基因表达比直接提高了脂肪酸的去饱和速率;FAD2、FAD3、FAD7和FAD8基因在亚油酸和亚麻酸快速合成期间同时出现明显的表达量峰值,进而促进油酸逐步去饱和为亚油酸和亚麻酸。研究认为,沙棘种子油高积累碳十八不饱和脂肪酸源于FATB和Δ9 D基因的低表达及KAR、KASⅡ、SAD、FAD2、FAD3、FAD7和FAD8基因的协同高表达,本研究结果为进一步理解种子油中碳十八不饱和脂肪酸的合成积累提供了理论依据,对改良植物油脂的不同脂肪酸比具有重要意义。     

乌桕梓油和桕脂的脂肪酸组成研究

运用色谱-质谱分析方法,鉴定乌桕梓油和桕脂的脂肪酸成分.分析结果,野生乌桕和栽培乌桕在脂肪酸组成上相同;梓油除了含常见的亚麻酸、亚油酸、油酸、棕榈酸和硬脂酸之外,还含有不常见的2,4-癸二烯酸和8-羟基-5,6-辛二烯酸;桕脂含棕榈酸、油酸、硬脂酸和亚油酸.两者的主要差异在于蜡质层厚度和核的大小及其油脂含量的不同.     

乌桕梓油和桕脂的脂肪酸组成研究

运用色谱-质谱分析方法,鉴定乌桕梓油和桕脂的脂肪酸成分.分析结果,野生乌桕和栽培乌桕在脂肪酸组成上相同;梓油除了含常见的亚麻酸、亚油酸、油酸、棕榈酸和硬脂酸之外,还含有不常见的2,4-癸二烯酸和8-羟基-5,6-辛二烯酸;桕脂含棕榈酸、油酸、硬脂酸和亚油酸.两者的主要差异在于蜡质层厚度和核的大小及其油脂含量的不同.     

不同加工工艺对真空油炸花生品质特性的影响

探讨了不同加工工艺对真空油炸（VF）花生品质特性的影响,结果表明：与对照相比,浸泡处理使VF花生制品容重显著下降;冷冻处理可以增加制品得率和酥脆度,提高商品性,不造成对制品理化指标的显著影响;蒸煮处理对制品的理化指标均无显著影响;随着真空油炸温度的升高,花生制品的容重、得率、脂肪、油酸呈升高趋势,亚油酸、棕榈酸呈现下降趋势。与原料相比,经浸泡、蒸煮和冷冻处理后,VF花生制品的脂肪、油酸、山梨酸、硬脂酸、花生酸含量显著升高,亚油酸、棕榈酸、组氨酸、脯氨酸含量显著下降,而蛋白质及必需氨基酸等指标变化较小。相关性分析表明,脂肪、蛋白质、油酸、亚油酸、Arg、Leu、容重、得率等理化指标之间呈现显著或极显著相关关系。     

苹果种籽中脂肪酸组分分析

用气相色谱-质谱联用技术分析5个品种苹果籽中脂溶性成分的结果表明：苹果籽中脂溶性成分的提出率为26．6％;以亚油酸、油酸、棕榈酸、硬脂酸、花生酸为主,亚油酸和油酸含量最高。     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。