内源激素对落叶果树芽休眠的调控

在落叶果树芽的休眠过程中,内源激素是一个非常重要的影响因子。本文对落叶果树芽休眠期间内源激素的变化动态,及其这种变化与落叶果树芽休眠的诱导、终止和调控的关系,以及其中的内在机制作了综述。     

落叶果树芽休眠调控研究进展

在自然条件下 ,温带落叶果树为了适应冬季的低温 ,芽在外表上停止生长的现象 ,称为芽的休眠。休眠是一个十分复杂的现象 ,关于落叶果树芽的休眠及其调控机理 ,目前人们还不清楚。随着近年来设施栽培面积的不断增大 ,休眠问题成为研究领域的一个热点 ,并已取得了很大进展。1　芽休眠的分类　　迄今为止 ,休眠的分类尚未规范化 ,根据不同的标准 ,可将其划分为不同的种类和休眠阶段。1 1　按照芽休眠的生理活性划分　a 自然休眠(naturaldormancyorspontaneousdormancy) ,是指即使给予适宜生长的外部环境条件芽仍不能萌发生长 ,而需要经过一定的…     

温度对落叶果树休眠解除影响的研究进展

温度是影响落叶果树芽休眠解除最主要的因素,直接关系到促成栽培的成败.现综述不同温度类型对落叶果树芽休眠解除的影响,以期对设施栽培提供理论依据.     

葡萄休眠芽上鳞片的作用

多年生的果树常常一边在叶腋里形成腋芽,一边枝条向前伸长。一般落叶果树在温带其腋芽从夏末到秋季进休入眠,冬季遭遇低温后休眠被打破,早春萌发生长。目前有许多研究者正在研究木本植物芽的休眠,但是,在芽的休眠及发芽生理方     

‘翠冠’梨花芽休眠期碳水化合物变化及其相关基因表达研究

 以‘翠冠’梨（Pyrus pyrifolia Nakai）花芽为试材,连续两年研究了其在休眠过程中的碳水 化合物含量变化及编码α–淀粉酶、β–淀粉酶和α–葡聚糖磷酸化酶等碳水化合物代谢相关基因的表达 模式。两年的结果显示,随着‘翠冠’梨花芽休眠的加深,可溶性糖含量逐渐下降,11 月15 日降到最低。 此后,在内休眠及其解除过程中可溶性糖含量呈上升趋势。花芽中淀粉含量随着休眠的加深逐渐下降, 最低含量出现的时间在年度间有所不同。随着休眠开始解除,淀粉含量逐渐增加,在完全解除前达到最 大值,其后则逐渐下降。‘翠冠’梨花芽的PpAMY、PpBAM1、PpBAM2 和PpPHS 在内休眠阶段均出现一 个表达高峰,然后逐渐下降直到内休眠完全解除前。之后,除PpBAM2 外,其余3 个基因再次上调表达。 ‘翠冠’梨花芽休眠期间,淀粉含量的变化与PpAMY、PpBAM1、PpBAM2 和PpPHS 的表达变化之间存 在联系,由此推测这些基因可能参与了‘翠冠’梨花芽休眠期碳水化合物代谢的调控。     

落叶果树芽自然休眠诱导的研究进展

落叶果树芽的自然休眠诱导是一个理论和实践上都很重要但至今还未弄清楚的问题。重点阐述了自然休眠诱导和冷适应的关系、诱导休眠的自然环境因素、激素与休眠诱导的关系、休眠诱导期间芽与邻近组织的竞争、休眠诱导期间顶端分生组织的动力学及休眠诱导期间发生的某些重要的生理活动和休眠诱导的分子生物学等方面的内容,并指出了今后休眠诱导研究的重点问题。     

茶树CsAIL的克隆及在不同休眠阶段的表达分析

从茶树不同休眠状态腋芽转录组中筛选出一条差异表达基因,经全长克隆和同源性分析证实该基因为与多年生植物休眠的形成和解除密切相关的AINTEGUMEN-LIKE(AIL)的同源基因,命名为CsAIL。生物信息分析表明,该基因包含1个1 872 bp的开放阅读框,编码623个氨基酸。编码的蛋白质分子质量为69.2kD,理论等电点为6.6,是一种非分泌性蛋白;该蛋白有两个保守的AP2结构域,是植物中特有的广泛参与生长发育调节的AP2亚家族成员。亚细胞定位预测CsAIL蛋白不存在于叶绿体或者线粒体中,可能定位于其他细胞器;经同源性分析,在‘云抗十号’和‘舒茶早’全基因水平上分别鉴定了11个和12个AIL同源基因。系统进化树及序列保守性分析显示,Cs AIL与‘云抗十号’CSA001743.1和‘舒茶早’TEA027750.1的进化关系最近,与已知的拟南芥AIL蛋白处于不同分支,但具有典型的保守结构域和已知的重要氨基酸位点。启动子序列分析显示该基因可能受生理节律、光及多种激素等信号共同调控。CsAIL在茶树顶芽、腋芽和茎中的表达量较高,叶片中较低,花中几乎不表达。在茶树冬季类休眠和生理休眠阶段,该基因的表达量在叶和越冬芽中均逐渐下调并维持在较低水平;在生态休眠及萌动阶段显著上调。分析其可能的下游调控基因CsCYCD3.2和CsCYCD6.1的表达,二者与Cs AIL的表达模式高度一致,与越冬芽的休眠状态存在高度关联。本研究表明,CsAIL可能是参与茶树休眠调控的关键基因,与CsCYCDs共同在茶树年休眠—生长循环中发挥作用。     

梨芽内休眠分子调控机制研究进展

多年生木本植物芽休眠是植物生长发育过程中的一种可见生长暂时停止的现象,是植物经过长期演化而获得的一种对环境及季节性变化的生物学适应性。对梨芽内休眠分子机制研究的最新进展进行了综述,阐述了梨休眠的建立与解除过程的调控因素,介绍了梨内休眠过程重要转录因子DAM的发现及其参与的分子网络调控模式,并对有关休眠机制未来的研究方向提出了展望。     

植物花青素基因的克隆及应用——文献综述

评述了近十年来有关植物花青素的基因克隆研究进展及其应用前景。植物花青素代谢途径及其主要酶类的作用之研究已较为成熟，一大批调控植物花色的结构基因与调节基因已被克隆。利用外源基因导入、反义基因及共抑制原理已培育出了新色系观赏植物品种。用基因工程的方法培育蓝色月季的工作正在进行。利用结构基因和调节基因为创造新花色、植物体彩化、植物生长发育及研究植物的花青素代谢等开辟了广阔前景     

The influence of fruiting on the bud sprouting and flower induction responses to chilling in Citrus

Summary

The effect of chilling temperatures on bud sprouting and flower formation was compared on fruiting and non-fruiting ‘Owari’ satsuma mandarin (Citrus unshiu Marc) trees. On non-fruiting trees, bud dormancy was weak, and a significant proportion of buds were able to sprout at high temperatures without being chilled. Separate effects of low temperatures on bud sprouting and flower induction were demonstrated. On fruiting trees these two effects of low temperatures were also demonstrated on summer-flush buds, but not on older (spring-flush) buds. The spring-flush buds from fruiting trees scarcely sprouted without being chilled. These buds required a longer chilling period for dormancy release than for flower induction, and it was not possible to separate the effect of low temperature on flower induction from the effect on dormancy release. The presence of fruit reduced flower formation by reducing bud sprouting. Furthermore, fruit had a direct inhibitive effect on vernalization which resulted in increased formation of vegetative shoots. The effect of fruit and low temperature on flowering was unrelated to carbohydrate accumulation in the leaves or the roots.     

Simultaneous down-regulation of DORMANCY-ASSOCIATED MADS-box6 and SOC1 during dormancy release in Japanese apricot (Prunus mume) flower buds

In temperate deciduous fruit crops such as Prunus spp., bud endodormancy is an important physiological phase affecting the timing of blooming and subsequent fruit development. Japanese apricot (Prunus mume) bears unmixed flower buds, separate from vegetative buds, that bloom slightly more than a month before vegetative bud burst. Seasonal expression of Prunus mume DORMANCY ASSOCIATED MADS-box genes (PmDAMs) has previously been analyzed only in vegetative buds, with an association between these genes and flower bud endodormancy release not yet confirmed. In this study, we performed a seasonal expression analysis of PmDAM1–6 genes in flower buds of two Japanese apricot genotypes – namely, high-chill and low-chill cultivars. The analysis revealed that PmDAM3, PmDAM5, and PmDAM6 expressions are closely associated with dormancy release in both flower and vegetative buds. In addition, a yeast two-hybrid screening demonstrated that PmDAM6 can interact in yeast with the homolog of Arabidopsis SOC1 (PmSOC1). Synchronized expression patterns were detected in PmDAM6 and PmSOC1 during dormancy release in flower buds of the two genotypes. Taken together, these results suggest that the dimer of PmDAM6 and PmSOC1 may play a role in the regulation of dormancy transition and blooming time in Japanese apricot flower buds.     

影响南京甜樱桃坐果的关键时期

研究不同生育期的生态条件对甜樱桃花芽分化和坐果的影响,确定导致南京地区（年均温 > 15 ℃）甜樱桃坐果率低的关键时期,将郑州的一部分4年生盆栽结果甜樱桃运至南京生长1年后,然后将郑州和南京两地的盆栽苗分别在落叶期、休眠结束后进行双向位置交换,采用石蜡切片法观察花芽和胚囊形态发育,并在果实着色期观察坐果率。结果显示：全生育期在郑州、落叶期由郑州运至南京、休眠结束后由郑州运至南京、全生育期在南京、落叶后由南京运至郑州的‘早红宝石’甜樱桃坐果率分别为38.2%、14.7%、12.9%、8.9%和31.7%;无胚囊的比例分别为41.5%、55.6%、57.7%、74.5%和50.0%;全生育期在郑州和落叶后由郑州运至南京休眠结束后再运回郑州的甜樱桃‘萨米脱’的坐果率分别为13.9%和18.8%。结果表明：影响南京地区甜樱桃坐果的关键时期应是春季开花坐果期;而对于一些能满足需冷量的品种,休眠期对坐果率的影响不大;夏季花芽分化期的高温影响花芽分化进程及分化质量。     

不同需冷量桃休眠相关DAM基因表达特性及激素调控的响应分析

以"南山甜桃"(需冷量200 h)、"瑞光51号"(需冷量400 h)和"春美"(需冷量600 h)为试材,从大量落叶期开始至花芽萌动期间,约每15 d采样一次,RT-PCR分析DAM基因在不同冷量积累时期花芽中的表达量,PLC-MS-MS测定相同时期吲哚乙酸(IAA)、脱落酸(ABA)和玉米素(ZT)含量变化,以期了解不同需冷量桃休眠过程中DAM基因的表达特性及激素的调控机理。结果表明:DAM基因在不同需冷量桃休眠过程中的表达趋势一致,随着休眠的深入,"春美"中DAM基因的表达水平呈先升后降趋势;"南山甜桃"和"瑞光51号"在进入休眠期以后DAM基因表达水平急剧下降,与低温积累量呈负相关。"春美"中DAM基因表达量明显高于"瑞光51号"和"南山甜桃"。"春美"中DAM基因表达水平比"南山甜桃"和"瑞光51号"开始下调约晚30 d,但"瑞光51号"和"南山甜桃"中DAM基因下调的时间一致。IAA、ZT在不同需冷量桃休眠过程中的含量变化差异不显著,ABA含量变化差异显著,可能在休眠解除过程中起重要调控作用。     

落叶果树需冷量及其机理研究进展

落叶果树需冷量的准确估算是果树栽培尤其是果树促成栽培中的一个关键因素,直接关系到果树促成栽培的成败。综合有关文献,介绍了落叶果树需冷量的概念、估算方法、研究现状、生物学机制和存在问题。低温可以诱导休眠,休眠解除需要低温积累,从植物生理学和分子生物学角度阐述了落叶果树需冷量的机理。并对缩短落叶果树自然休眠期的可能途径从育种、施用外源化学药剂、环境调控3个方面进行了初步探讨。     

The influence of autumn temperature on flowering time and cropping of Pyrus communis cv. Conference

The influence of autumn temperatures on flowering and cropping date was examined for Pyrus communis cv. Conference. Warming potted trees in both October and November delayed bud development and the date of blossoming, relative to unheated control and field-grown trees. The later the warming treatment was applied in the autumn, the more the flowering date was delayed. The delay in flowering date is suggested to be due to an increase in bud dormancy in response to a reduction in winter chilling. Mean fruit yields and fruit number per tree were greater in trees warmed during October compared with unheated control trees, but declined with heating in November. Some evidence is presented which suggests that flower number per cluster may decline with warming. Both the initial and final set increased with warming. Fruit set was also likely to have been influenced by treatment differences in fruit number per tree. The results of this work are discussed in relation to attempts to provide a physiological understanding of recently reported effects of temperature on the year-to-year variation in cv. Conference cropping.     

Effects of fruit load on flower bud initiation and development in peach

Summary

This study aims to quantify the effects of fruit crop-load on flowering and to determine the relationships between flowering and phloem sap carbohydrate and nitrogen content fractions from budding to dormancy in ‘Zincal 5’ nectarine. Fruit load significantly reduced the number of flowers per tree both indirectly, by reducing the number of shoots per tree and the number of nodes per shoot, and directly, by reducing the number of floral buds per node. The intensity of the response depended on the number of fruits developed per tree. Trees that kept all fruits up to senescence flowered 35% less than trees thinned by hand to 40% of fruits at pit hardening, and 55% less than trees completely thinned in bloom by hand. Trees that kept all fruits had significantly lower glucose and sorbitol contents in the phloem sap of mixed branches up to harvest date and full vegetative growth, respectively, but no significant relationships were found between the concentrations of these carbohydrates and flowering intensity in the following Spring. Sucrose and fructose did not show any significant difference in regard to crop-load. In fibrous roots, starch content was not related to fruit load up to dormancy, indicating that starch content is not associated with flower bud induction and differentiation. The nitrate-nitrogen fraction was significantly higher, and the ammonium-nitrogen fraction was significantly lower, in trees that tended to flower less, suggesting some disturbance in nitrate reduction in these trees.     

Next generation sequencing reveals the potential functions of the genes involved in controlling several important commercial traits in peach (Prunus persica (L). Batsch) fruits

Next-generation sequencing techniques provide a new insight into the genetic bases of the most important commercial traits in fruit trees. The genomic deep sequencing results of peach cultivar ‘Xiaobaitao’ and its bud variation type ‘Jinliuzaohong’ are reported here. The numbers of detected Single nucleotide polymorphisms (SNPs) in wild type and in mutant were 591,485 and 593,484, with that of InDel as 113,934 and 115,065, respectively. Interestingly, the numbers of SNPs and InDels that differentiate ‘Jinliuzaohong’ from ‘Xiaobaitao’ were 50,217 and 19,368, respectively. The number of genes with non-synonymous mutation was 887, which involved in 109 pathways. The authors found dozens of genes involved in the important commercial traits of peach fruit which are of variations in Coding sequence (CDS) regions, including 3 NAC family genes, i.e. NAC66, NAC68, and NAC78. The relevant commercial traits of peach fruit include colour coverage, maturity date, fruit size, and sugar content. A phylogenetic tree of homological NAC proteins indicated relationship among the species. Genome sequence data suggested that a series of genes and several genetic pathways were likely involved in the formation of the important traits in peach fruits. The findings provide new evidence for the functions of the candidate genes controlling peach fruit traits which were proposed previously by researchers using QTL analysis.