Effect of Nutrient Restriction and Compensation on Weight,Serum Indexes and Gene Expression of Chest Fat Adipokines in Mongolian Lamb

To study the effect of nutrient restriction and compensation on weight,serum indexes and gene expression of chest fat adipokine in Mongolian lamb,thirty male lambs were randomly divided into control group (20.26 kg± 3.63 kg) and feed restricted group (21.29 kg±3.00 kg).The experiment lasted for 120 days,including 60 days for feed restriction and 60 days for compensatory feed.At the end of each stage,five lambs from each group were slaughtered and chest fat was collected.Serum concentration of triglycerides,non-esterified fatty acids (NEFA),total cholesterol were measured.Quantitative Real-time PCR were used to determine Adiponectin,Visfatin,PPAR-γ and ACC genes expression.The results showed that:①The lamb body weight of restricted group kept maintain level and that of control group showed a increase tendency.During the compensatory period,the average daily gain (ADG) of restricted group was significantly higher than control group (P< 0.05).②During the restriction period,serum triglycerides concentration of lambs in restricted group was significantly decreased at day 30 and 60 (P< 0.05),and NEFA concentration was significantly increased at day 30 (P< 0.05).After 60 days of nutritional compensation,all serum parameters we tested were not significantly different between restrict group and control group (P >0.05).③During the restriction period,PPAR-γ and ACC gene expression in restricted group were significantly lower than that of control group (P< 0.05),while no significant differences were found during the compensation period (P>0.05).Adiponectin and Visfatin genes expression in chest fat was not significantly changed throughout the experiment (P >0.05).We could know that nutritional restriction reduced fatty acid synthesis and adipocyte differentiation ability,adipose tissue was mobilized energy metabolism,and total cholesterol was recoveried growth on the compensation.However,the ACC and PPAR-γ genes in restricted group were significantly decreased with the body weight increased rapidly during the compensatory stage.Adiponectin and Visfatin were not significantly different between restricted and compensatory stages.     

A non-ACC pathway for ethylene biosynthesis in Botrytis cinerea

Premature softening and tissue senescence occur in kiwifruit infected with Botrytis cinerea. While ethylene production is enhanced in infected fruit and B. cinerea produces ethylene on defined media in vitro the source of ethylene in this pathosystem is unclear. Ethylene production by B. cinerea was enhanced when methionine or ∝-keto-methylthiobutyric acid (KMBA) was added to a defined (modified Pratts) medium. Although 1-aminocyclopropane-1-carboxylic acid (ACC) did not stimulate ethylene production, ∝-aminooxyacetic acid (AOA) was inhibitory suggesting a role for a pyridoxal phosphate mediated enzyme reaction down stream from the methionine/KMBA stimulated ethylene biosynthetic pathway. Cobalt chloride (Co²⁺) was inhibitory, but after a 4-d lag period ethylene production from B. cinerea cultures containing methionine and Co²⁺ reached the same level as those without Co²⁺. [U ¹⁴C] methionine was converted to ¹⁴C-ethylene with high efficiency indicating that it is a direct precursor, while [2,3 ¹⁴C]-ACC did not yield radioactively labelled ethylene. These results suggest that the ethylene biosynthetic pathway in B. cinerea does not involve ACC as a precursor and that the enzyme responsible for synthesising ethylene is similar to, but different from, ACC oxidase from higher plants. The ethylene biosynthetic pathway in B. cinerea is yet to be determined.     

间隙升温处理对芒果内源多胺和ACC含量的影响

紫花芒果在冷害低温中贮藏，对其进行间隙升温处理。结果表明：芒果发唾冷害以后，其内源ＳＰＤ和ＳＰＭ含量显著增加，但内源ＰＵＴ和ＣＡＤ含量的变化不显著；冷害还导致了ＡＣＣ的累积。间隙升温处理显著地减轻了芒果的冷害，延迟了多胺及ＡＣＣ含量的上升。     

小麦胆色素原脱氨酶的电泳性质分析

经反应红１２０亲和层析纯化的小麦胆色素原脱氨酶（Ｐｏｒｐｈｏｂｉｌｉｎｏｇｅｎ ｄｅａｍｉｎａｓｅ,ＰＢＧＤ,ＥＣ．４,３,１,８）,在ＳＤＳ－ＰＡＧＥ和ＩＥＦ－ＰＡＧＥ上均显示一条带,表明已ＰＢＧＤ纯化至均一,它的亚基分子量３６ＫＤ,ｐＩ为４．８。酶活性染色呈一条带,表明无同工酶存在。ＰＡＧＥ显示两条带,证明小麦幼苗中存在酶与底物结合的中间物。脲梯度电泳呈现之字形,在４ｍｏｌ／Ｌ的脲浓度下可使酶     

反义ACC氧化酶基因的导入对番茄乙烯生成的抑制作用

将反向克隆的ＡＣＣ氧化酶基因通过Ｔｉ质粒导入到番茄基因组中，转基因番茄植株叶片和果实中ＡＣＣ氧化酶活性和乙烯产生速率均受到显著抑制，显示出反义基因能抑制靶基因（ＡＣＣ氧化酶）的表达。子代抗性标记基因的分离结果表明呈单基因遗传。     

黄河蜜甜瓜1-氨基环丙烷1-羧酸合成酶基因片段的克隆和反义载体的构建

从伤诱导的黄河蜜甜瓜(Cucumismelocv.Huanghemi)成熟果实的中果皮组织中分离总RNA,经反转录和PCR扩增得到974bp的cDNA片段,克隆到质粒载体pGEM-3zf,经测序与Genbank中甜瓜1-氨基环丙烷1-羧酸合成酶(1-amino-cyclopropane-1-carboxylieacidsynthase,ACS)基因同源性为99%。克隆片段经双酶切消化,反向插入到植物表达载体pBI121的35S启动子和NOS终止子之间,构建成ACS基因的反义表达载体。     

PG,ACC,乙烯对番茄果实成熟的影响

番茄果实在成熟过程中硬度下降迅速，ＰＧ活性急剧上升，表现出显著的负相关；用ＡＣＣ和乙烯利处理绿熟期果实，结果乙烯促进了正常番茄和ａｌｃ番茄果实成熟进程，其ＰＧ活性也升高，而外源乙烯和ＡＣＣ不影响ｎｏｒ基因突变体果实的成熟进程。ＡＣＣ和ＰＧ无直接关系。     

The effect of humidity in plantain ripening

An examination of the coordination of ripening changes in plantain fruits (Musa AAB, cultivar ‘Apem’) showed that water stress had no effect on the respiratory rate at the climacteric maximum nor on the time between initiation and maximum. Similarly, water stress had little or no effect on the coordination of changes in CO₂ and C₂H₄ evolution, although it slightly increased the magnitude of C₂H₄ production and of the ACC content of the pulp. Stressed and unstressed fruits showed similar synchronised ripening changes after 2 and 3 days from the commencement of the climacteric. However, after 1 day, peel colouration, pulp softening and total soluble solids were less in stressed than in unstressed fruits. The results are discussed in the light of reported work on dessert bananas (Musa AAA cultivars).     

黄瓜性别决定相关基因在不同性型黄瓜种质基因组中的分布

根据已有的决定黄瓜雌性的ACC合酶基因CS-ACS1G,与黄瓜性型有关的ACC氧化酶基因CS-ACO2、CS-ACO3,与黄瓜雌性相关的乙烯受体基因CS-ETR2和CS-ERS的序列,通过设计特异引物,对不同性型黄瓜品种基因组DNA进行扩增。结果表明,5个基因在本试验所用的不同性型黄瓜品种的基因组中均能被检测到,说明这5个性别决定相关基因在本试验中不具有雌性特异性。通过PCR克隆在全雌性黄瓜品种G5224中获得了长度为1 124 bp的ACC合酶基因序列。BLAST分析表明,本试验所获得的ACC合酶基因序列和Trebitsh公布的CS-ACS1G基因序列的同源程度为99 %,表明PCR扩增产物确实为CS-ACS1G基因。此基因在基因组中表现不具雌性特异性的现象与多数研究者的结论相悖。