木本植物营养贮藏蛋白质研究进展

本文根据最新的国内外研究资料对木本植物营养贮藏蛋白质的分类、定位、生化特性和生理功能等方面进行了全面的综述;着重论述了林木营养贮藏蛋白质的合成、转移、降解机理及基因表达与调控等方面的最新研究进展;对有待进一步研究的领域也进行了分析和讨论。     

种子贮藏蛋白合成与调节的研究进展

种子贮藏蛋白的合成机制是目前生物化学、农业、食品工业及生物技术极为关心及重点研究的课题之一,本文对贮藏蛋白及其基因、贮藏蛋白的合成、翻译后的修饰及合成的调节等最新研究进展,进行了较详细的讨论。     

贮藏条件对川硬皮肿腿蜂存活率的影响

在相对湿度为50%~70%的条件下,设置5个温度梯度,将川硬皮肿腿蜂SclerodermasichuanensisXiao雌成蜂分别进行直接贮藏和定期补充15%蜂蜜水后贮藏,并对该蜂在不同条件下的贮藏存活率进行了比较。结果表明,贮藏温度和补充营养对川硬皮肿腿蜂雌成蜂的存活率有显著影响,其中6~15℃下贮藏相同时间的蜂存活率较高,比较适合该蜂的贮藏,而在12℃贮藏相同时间的供试蜂存活率最高,最适该蜂的贮藏。除此之外,在贮藏期间适时添加补充营养也能大大延长川硬皮肿腿蜂雌成蜂的贮藏寿命,但补充营养对该蜂存活率的影响大小与贮藏温度有关。     

银杏营养贮藏蛋白质的亚细胞定位

在电子显微镜下,对银杏(Ginkgo biloba L.)枝条营养贮藏蛋白质的超微结构特征及在亚细胞水平的定位进行了系统研究.结果表明:银杏营养贮藏蛋白质主要存在于韧皮薄壁细胞的液泡内.银杏韧皮薄壁细胞内的营养贮藏蛋白质在细胞质内合成,由内质网膨大的槽库、质膜内折或高尔基体小泡发育形成贮藏蛋白质的液泡.液泡蛋白质主要以不定形块状、絮状或颗粒状形态存在.贮藏蛋白质在整个越冬期一直保持高含量,直到翌年春季萌芽时,贮藏蛋白质迅速转移再利用.随着新梢的生长,到了夏末秋初,又重新开始积累贮藏蛋白质.     

PENG Fang-Ren银杏营养贮藏蛋白质的亚细胞定位(英文)

在电子显微镜下,对银杏(GinkgobilobaL.)枝条营养贮藏蛋白质的超微结构特征及在亚细胞水平的定位进行了系统研究。结果表明:银杏营养贮藏蛋白质主要存在于韧皮薄壁细胞的液泡内。银杏韧皮薄壁细胞内的营养贮藏蛋白质在细胞质内合成,由内质网膨大的槽库、质膜内折或高尔基体小泡发育形成贮藏蛋白质的液泡。液泡蛋白质主要以不定形块状、絮状或颗粒状形态存在。贮藏蛋白质在整个越冬期一直保持高含量,直到翌年春季萌芽时,贮藏蛋白质迅速转移再利用。随着新梢的生长,到了夏末秋初,又重新开始积累贮藏蛋白质。     

杨树新梢积累营养贮藏蛋白质的细胞学研究

采用光学显微镜和电子显微镜技术,对杨树新梢中的营养贮藏蛋白质进行了细胞学鉴定。在用戊二醛固定的标本中,营养贮藏蛋白质呈颗粒状,积累在中央大液泡里。在新梢伸长生长时期,新梢茎的基部已积累了营养贮藏蛋白质,在伸长生长刚停止,中上部的叶片近成熟时,整个新梢的茎都有营养贮藏蛋白质的积累,其中,以新梢基部的茎最为丰富。营养贮藏蛋白质优先在次生韧皮部的韧皮薄壁细胞和韧皮射线薄壁细胞中积累,在新梢伸长生长停止后,新梢基部茎的木质部中也积累了相当数量的营养贮藏蛋白质,主要分布在初生木质部和内侧次生木质部的各种生活的薄壁细胞中。新梢较早地积累营养贮藏蛋白质是热带树木和温带树木的一个共同特点,对于树木的氮代谢和树木当年的生长发育可能具有重要的调控作用。     

银杏营养贮藏蛋白质的亚细胞定位

在电子显微镜下,对银枵（Ginkgo biloba L.）枝条营养贮藏蛋白质的超微结构特征及在亚细胞水平的定位进行了系统研究。结果表明：银杏营养贮藏蛋白质主要存在于韧皮薄壁细胞的液泡内。银杏韧皮薄壁细胞内的营养贮藏蛋白质在细胞质内合成,由内质网膨大的槽库、质膜内折或高尔基体小泡发育形成贮藏蛋白质的液泡。液泡蛋白质主要以不定形块状、絮状或颗粒状形态存在。贮藏蛋白质在整个越冬期一直保持高含量,直到翌年春季萌芽时,贮藏蛋白质迅速转移再利用。随着新梢的生长,到了夏末秋初,又重新开始积累贮藏蛋白质。     

贮藏条件对鱼肉品质的影响研究进展

综述了鱼肉在不同贮藏条件下的品质变化，以及不同处理方式对贮藏品质的影响的研究进展，旨在为改善鱼肉的贮藏条件和更深入的研究提供科学依据。 关键词：鱼肉；储藏；营养品质；理化品质；保质期     

苹果类胡萝卜素研究进展

类胡萝卜素是苹果果实色泽形成的一个重要影响因子，其种类和含量决定果实是否具有良好的外观和丰富的营养。本文综述了近年来有关苹果果实类胡萝卜素方面的研究进展，并对苹果类胡萝卜素的种类和含量，苹果发育和贮藏过程中类胡萝卜素含量的变化规律，生物合成途径中相关基因的表达，以及环境因子对类胡萝卜素积累的影响等方面进行了阐述。     

1-MCP、壳聚糖和臭氧在鲜切果蔬保鲜技术中的研究进展

鲜切果蔬因其新鲜、营养和方便的优点而日益受到消费者喜爱,但鲜切果蔬在经过清洗、去皮、切分等工序后,其产品组织结构受到损伤,从而导致组织褐变、微生物侵染及营养损失等问题的出现,严重缩短了鲜切产品的货架期。因此,对鲜切果蔬贮藏保鲜技术的研究已经成为近年来农产品贮藏与加工领域的热点。本综述简述了1-甲基环丙烯、壳聚糖和臭氧,这3种化学保鲜方法在鲜切果蔬中的研究现状,期待能为鲜切果蔬保鲜技术的深入研究提供参考依据。     

植物营养贮存蛋白及其生物学功能研究进展

植物营养贮存蛋白(vegetative storage proteins )是广泛存在于植物营养组织且含量丰富的蛋白, 最初是作为植物氮源的临时贮存形式而被人们认识。然而, 不同植物中的营养贮存蛋白的生化来源和生物学特性并不相同, 并且除了营养贮存功能外, 更重要的是这类蛋白在植物防御中也承担着多种多样的重要角色, 或具有抗虫活性, 或能够抑制病原细菌和病原真菌的生长, 或参与植物防御过程中的信号转导等。对植物营养贮存蛋白在植物防御中作用机制的深入研究将使这类蛋白在新型生物农药的开发和植物抗病基因工程中具有广阔的应用前景。     

植物营养贮存蛋白及其生物学功能研究进展

植物营养贮存蛋白（vegetative storage proteins）是广泛存在于植物营养组织且含量丰富的蛋白，最初是作为植物氮源的临时贮存形式而被人们认识。然而，不同植物中的营养贮存蛋白的生化来源和生物学特性并不相同，并且除了营养贮存功能外，更重要的是这类蛋白在植物防御中也承担着多种多样的重要角色，或具有抗虫活性，或能够抑制病原细菌和病原真菌的生长，或参与植物防御过程中的信号转导等。对植物营养贮存蛋白在植物防御中作用机制的深入研究将使这类蛋白在新型生物农药的开发和植物抗病基因工程中具有广阔的应用前景。     

Soybean vegetative storage protein structure and gene expression

Depodded soybean (Glycine max [L] Merr. cv Williams) plants accumulate high levels of a glycoprotein in their leaves that has many features of a storage protein. The protein is found in all vegetative tissues which have been examined but not in the seeds. Translation in vitro indicated that elevated mRNA levels were at least partially responsible for the specific increase in vegetative storage protein. cDNA clones were isolated and sequenced, and an amino acid sequence was predicted. Although the amino acid composition is similar to that of seed storage proteins, no sequence similarity could be detected. Northern blot hybridization confirmed a large increase in vegetative storage protein mRNA in leaves of depodded plants. The vegetative storage proteins are represented by about four gene copies in the haploid genome.     

Wheat vegetative nitrogen compositional changes in response to reduced reproductive sink strength

N redistribution patterns and the N composition of vegetative tissues above the peduncle node of wheat (Triticum aestivum L.) plants with altered reproductive sink strength were evaluated to determine the role of vegetative storage proteins in the temporary storage of excess N destined for export. The degree of leaf senescence symptoms (loss of chlorophyll, total N, and ribulose-1,5-bisphosphate carboxylase/oxygenase) were initially reduced, but the complete senescence of vegetative tissues proceeded even for plants completely lacking reproductive sinks. Plants with 50% less sink strength than control plants with intact spikes redistributed vegetative N to the spike almost as effectively as the control plants. Plants without reproductive sinks exported less N from the flag leaf and had flag leaf blades and peduncle tissues with higher soluble protein and α-NH₂ amino acid levels than control plants. An abundant accumulation of polypeptides in the soluble protein profiles of vegetative tissues was not evident in plants with reduced sink strength. Storage of amino acids apparently accommodates any excess N accumulated by vegetative tissues during tissue reproductive growth. Any significant role of vegetative storage proteins in the N economy of wheat is unlikely.     

Clonal variation in apical growth and content in vegetative storage proteins in Populus

Summary Apical shoot growth and storage protein content in various poplar species and clones were followed in trees growing in the field and in micropropagated plants cultivated in the growth chamber under a controlled environment. In autumn a 32 kD and a 36 kD vegetative storage protein accumulate in wood, bark and roots of poplar and comprise together about 25% of the soluble proteins. In spring, at the time of dormancy break, the storage proteins are degraded and 3 weeks after budburst these proteins are no longer immunologically detectable. As in autumn, short day exposure of black cottonwood plants (Populus trichocarpa Torr. and Gray) induces cessation of apical growth and accumulation of the 32 kD and 36 kD vegetative storage proteins in all clones studied. In order to simulate spring conditions, short day induced plants were transferred back to long days. Like the situation in spring, budburst and storage protein degradation occurred considerably earlier in clone 9/60 than in clone Muhle Larsen. The latter clone accumulates both in winter and after short day exposure more storage proteins than the former. Furthermore two P. trichocarpa clones differ qualitatively in storage protein content: they possess an additional 34 kD polypeptide which cross-reacts with the anti-32 kD antibody. In conclusion, apical shoot growth and the capacity to synthesize storage proteins can be easily followed in micropropagated poplar cultivated in the growth chamber under inducing photoperiods. This offers the major advantage of independence from the annual growth cycle. Within one species considerable clonal variance in storage protein content and in the induction times needed for dormancy and dormancy break were observed. The suitability of storage protein content and apical growth as early selection traits in breeding programs focusing on nitrogen efficient poplar and clones adapted to specific latitudes will be discussed.     

Combined expression of S-VSPalpha in two different organelles enhances its accumulation and total lysine production in leaves of transgenic tobacco plants

Soybean vegetative storage proteins (S-VSPs) accumulate to high levels in vacuoles of both wild types and heterologous plants. Here it is shown that directing S-VSPalpha to two different organelles-chloroplasts and vacuoles-in a single transgenic plant significantly increased its accumulation. Accumulation of S-VSPalpha in heterologous plants correlated with total soluble lysine. Using this approach with essential amino-acid-rich transgene proteins may lead to a breakthrough in improving plant nutritional quality.