植物自交不亲和基因研究进展

自交不亲和性的研究是植物生殖生物学和分子生物学研究的热点之一,对自交不亲和基因和蛋白质的深入研究是解析自交不亲和性机理的关键.对控制孢子体自交不亲和性和配子体自交不亲和性的S基因及其蛋白质产物的分子生物学研究进展进行了综述.孢子体自交不亲和性植物S位点上至少存在3个基因,即SLG、SRK和SCR基因.其中SLG、SRK基因控制雌蕊自交不亲和性,而SCR控制花粉自交不亲和性.配子体自交不亲和植物雌蕊S基因产物为S-RNase,具有核酸酶活性;配子体自交不亲和植物花粉S基因产物尚未找到.     

樱桃品种S基因型及自交不亲和性分子机制研究进展

系统介绍了樱桃S基因型鉴定的主要方法,全面列出上百个已知甜樱桃品种的S基因型,其中共涉及16个S基因;着重讨论了樱桃S基因座内S-RNase和SFB基因的研究概况、结构特点及位置关系,并提出该领域善待解决的问题。     

利用S倍点多态性快速测定甘蓝自交不亲和性及其S等位基因系

根据Ⅰ类和Ⅱ类ＳＬＧ基因两端序列合成了特异引物,对西南农业大学和ＨＲＩ（Ｈｏｒｔｉｃｕｌｔｕｒｅ Ｒｅｓｅａｒｃｈ Ｉｎｔｅｒｎａｔｉｏｎａｌ,Ｗｅｌｌｅｓｂｏｕｒｎｅ）提供了不同亲和指数的甘蓝９Ｂｒａｓｓｉｃａ ｏｌｅｒａｃｅａ Ｌ．）材料进行了ＰＣＲ分析。结果表明：具Ⅰ类ＳＬＧ基因的材料是强自交不亲和系,也包括弱自交不亲和系。因此,Ⅱ类ＳＬＧ基因的存在可作为区别甘蓝交亲和系和自交不亲和系的分子     

泛素/26S蛋白酶体途径与显花植物自交不亲和反应

植物的生长和发育离不开短命调控蛋白的有选择性降解,其中一种重要的降解方式就是泛素,26S蛋白酶体途径。在这个途径中,泛素（ubiquitin）和26S蛋白酶体起着至关重要的作用,需要被降解的蛋白会通过E1-E2-E3酶接合反应由Ub进行标记,随后标记蛋白会被26s蛋白酶体识别并降解。自交不亲和反应也正是通过此途径实现的,ARC1（arm repeat containing 1）和SCFs（skp1-cul1-F-box-proteins）作为E3s分别在孢子体自交不亲和和配子体自交不亲和反应中起作用。本文综述了就泛素/26S蛋白酶体途径的组成及其在自交不亲和反应中的作用。     

泛素/26S蛋白酶体途径与显花植物自交不亲和反应

植物的生长和发育离不开短命调控蛋白的有选择性降解, 其中一种重要的降解方式就是泛素/26S蛋白酶体途径。在这个途径中, 泛素(ubiquitin)和26S蛋白酶体起着至关重要的作用, 需要被降解的蛋白会通过E1-E2-E3酶接合反应由Ub进行标记, 随后标记蛋白会被26S蛋白酶体识别并降解。自交不亲和反应也正是通过此途径实现的, ARC1(arm repeat containing 1)和SCFs (skp1-cul1-F-box-proteins)作为E3s分别在孢子体自交不亲和和配子体自交不亲和反应中起作用。本文综述了就泛素/26S蛋白酶体途径的组成及其在自交不亲和反应中的作用。     

萝卜自交不亲和基因SLG6的CAPS标记的开发

萝卜是我国的主要蔬菜之一,其杂种优势十分明显,培育自交不亲和系是萝卜杂种优势育种的主要途径之一.本研究根据萝卜自交不亲和基因SLG6序列设计特异引物,以8个自交系为材料,其中自交不亲和系和自交亲和系各4个,扩增SLG6基因第232～711bp之间的单拷贝片段,8个材料均获得了一条480bp的特异片段.用限制性内切酶TaqⅠ对该片段进行酶切,自交不亲和系均产生约125bp和244bp的片段,其中,244bp的片段为自交不亲和系所特有,可作为SLG6基因的CAPS标记用于萝卜自交不亲和基因SLG6的检测;而自交亲和系则具有与自交不亲和系相同的125bp的片段和不同的多态性片段.     

确定梨自交不亲和基因型研究的技术进展

综述了运用杂交授粉试验和分子生物学方法等技术确定梨品种自交不亲和基因型研究的技术进展,分析了这些技术在确定梨品种自交不亲和基因型方面的优点和不足之处,并初步探讨了研究前景。因为HV区氨基酸的不同,不同S基因型也有所差异。因此,除了在分子生物学的水平上进行研究外,其他方法如mRNA、蛋白质和杂交授粉等水平上的研究在确定S基因型上也同样重要。     

11个苹果新品种自交不亲和基因的分离与鉴定

以11个苹果品种为试验材料,根据保守氨基酸序列"FTQQYQ"和"anti-1/WⅠPNV"设计苹果自交不亲和基因引物,利用酶切分析和目的片段DNA测序方法鉴定了9个新的S-等位基因,将该9个S-等位基因分别标记为:S34-、S35-、S36-、S37-、S38-、S39-、S40-、S41-、S42-等位基因,在GeneBank中的接收号依次为:EU310474、EU391605、EU391606、EU391607、EU391609、EU391610、EU391611、EU391612、EU391613。11个苹果品种的自交不亲和基因型分别为:桑萨(S40S40)、芳明(S1S9),烟嘎1(S38S27)、红金嘎拉(S39S27)、烟嘎2(S38S27)、青9号(S41S42)、阿斯(S36S36)、皇家嘎拉(S37S27)、静香(S1S9S34)、高岭(S38S9)、红奥(S35S35)。     

中国梨2个自交不亲和新等位基因(S等位基因)的分子鉴定

自交不亲和是显花植物的一种重要生殖生理现象,为探明中国梨的自交不亲和特性,对‘锦香’(Pyrus bretschneideri cv. Jinxiang)和‘鹅酥’(Pyrus bretschneideri cv. Esu)2个中国梨品种进行了基因组PCR特异扩增、S基因序列分析及田间杂交授粉试验。结果确定它们各含1个新S-RNA酶基因,分别命名为S37-和S38-RNase,GenBank序列号为DQ839238和DQ839239。生物信息学分析结果表明,S37-和S38-RNA酶的推导氨基酸序列与S1-至S36-RNA酶36个梨S基因具有相同的、高度保守的C1和C2区,但其高变区与S1-至S36-RNA酶差异较大,其中与S15的差异最小,只有3个氨基酸不同。在推导的氨基酸水平上,S37与S38有96%的序列相似性,但两者与S15的相似性更高,皆为98%,与S32的相似性最低,都只有63%;S37和S38的内含子较大,分别为786bp和723bp,与S15的777bp大小接近。最后,经分析验证确定‘锦香’和‘鹅酥’的S基因型分别为S34S37和S15S38。     

Expression and Possible Role of S4(SSM4) Genes in the Styles of Self-incompatible Pear Cultivar and Its Self-compatible Mutant

Stylar soluble proteins in self-incompatible “Nijisseiki” (S2S4), self-compatible “Osa-Nijisseiki” ( S2SSM4, SM means stylar-part mutant) and its progeny were analyzed by isoelectric focusing polyacrylamide gel electrophoresis (IEF-PAGE).SSM4-allele associated protein, SSM4-protein, existed in the style of “Osa-Nijisseiki” and its progeny. The SSM4-protein expressed only in the stigma of “Osa-Nijisseiki”, whereas in its original variety “Nijisseiki”, S4-protein expressed in the upper and lower parts of the style as well as in the stigma, and its expression amount decreased from the upper part to the lower part. The protein bands analyzed by IEF-PAGE were subjected to RNase activity staining. The results showed that the S4- and the SSM4-proteins have the similar molecular weights (approximately 30 kD) and RNase activity. The specific-activities measured with yeast RNA were similar, equivalent to approximately 275 U·min-1·mg-1 protein. The S SM4-protein showed almost the same inhibitory effects as the S4-protein on the pollen germination and the pollen tube growth with S4- and SSM4-alleles in vitro . From the above results, the reasons of the self-compatibility of “Osa-Nijisseiki” are considered as (1) low expression of the SSM4-gene and (2) the SSM4-gene expression only in stigma.     

培养基组分及pH值对梨花粉萌发和花粉管生长的影响

采用花粉液体培养法研究不同培养基组分和pH值对梨花粉萌发和花粉管生长影响.结果表明:培养基内硼酸、氯化钙、PEG-4000、蔗糖、葡萄糖、麦芽糖、山梨醇、果糖在一定浓度范围内,对花粉萌发及花粉管生长起促进作用,但超过一定浓度时起抑制作用;最适的培养基组分为:30mmol/LMES、0.01%硼酸、0.03%CaCl2·2H2O、15%PEG-4000、5%果糖 或5%山梨醇、10%蔗糖 ,最适的pH值为6.5.在该培养基内梨花粉萌发率约为59.2%,花粉管生长长度为966.3μm.     

‘晚大新高’梨授粉及受精过程的显微动态研究

应用荧光显微法和石蜡切片解剖法对‘晚大新高’梨授粉受精过程进行了系统观察研究。结果表明：‘晚大新高’梨自花授粉不结实;异花最佳授粉品种为‘黄花’,其次为‘翠冠’和‘丰水’。与选用‘黄花’为异花授粉品种相比,自花和异花的授粉受精过程存在明显差异,自花花粉在授粉后2h开始萌发,8h花粉管生长至离柱头约1／3处停止生长,顶端膨大呈球形,表现出自交不亲和性;异花花粉在授粉后1h开始部分萌发,8h花粉管生长至花柱中部,24h到达花柱基部并进入子房,48h进入胚囊,72h完成双受精过程。     

梨远缘花粉原位萌发及生长特性

应用荧光标记方法对梨远缘花粉在‘丰水’和‘噢嗄二十世纪’柱头上萌发及花粉管生长特性进行观察,结果表明:(1)梨远缘花粉均能在柱头上萌发,但其萌发率不同,授粉后24 h,在‘丰水’柱头上‘红叶桃’花粉萌发率最高,达62.8%,而‘盖县大李’花粉萌发率仅为12.0%,各种远缘花粉在‘丰水’柱头萌发率均高于‘噢嗄二十世纪’柱头。(2)各种远缘花粉管在梨柱头或花柱内生长情况也有差异,‘红叶桃’等核果类花粉管在梨柱头上均表现为扭曲、盘绕等现象,不能穿过柱头;‘红星’和‘红富士’花粉管虽然有少量穿过柱头,但不能进一步在花柱内生长,表现为扭曲变形、先端膨大等不亲和性现象。因此,梨与远缘果树杂交不亲和在柱头上就已发生,这与梨自交不亲和反应发生在花柱内的现象不同。     

植物生长调节物质对丰水梨花粉萌发和花粉管生长的影响

采用花粉液体培养法研究了植物生长调节物质对梨花粉萌发和花粉管生长的影响,结果表明：较低浓度的赤霉素、三十烷醇、吲哚乙酸及2,4-D均能促进花粉萌发和花粉管生长,而超过一定浓度时却起抑制作用,最适宜于花粉萌发和花粉管生长的赤霉素浓度为50～300mg／L,三十烷醇为3～100mg／L,吲哚乙酸为5～25mg／L,2,4-D为5～10mg／L。萘乙酸对花粉萌发和花粉管生长有抑制作用,抑制程度随培养基内其浓度的增大而加强。多效唑和脱落酸对花粉萌发有抑制作用,其抑制程度随浓度的上升而增强,但他们对花粉管生长却有促进怍用,其最适宜于花粉管生长的浓度分别为400mg／L和60mg／L,超过此浓度后,促进作用又有所下降,甚至出现抑制作用,如多效唑浓度达到1000mg／L时,能强烈地抑制花粉管生长。     

Structure and development of the stigma, style and ovary of Caesalpinia pulcherrima (L.) Sw., post-anthesis, pre- and post-pollination

The stigma of Caesalpinia pulcherrima is crateriform. The crater continues as a slit-like canal through the style and into the ovary. Both crater and canal are lined by several layers of fusiform and thin-walled cells which are continuous in two narrow regions in the ovary. Postanthesis and before pollination, the middle lamella of cells lining the stigmatic crater and stylar transmitting tissue undergoes dissolution. This occurs in a progression down the style with cells separating partially or wholly from neighbours. Dissolution is initiated at intercellular junctions where wall fibrils loosen and variously-sized and -shaped holes appear. Cytoplasmic changes include increased dictyosome activity, increased rough and smooth endoplasmic reticulum at the periphery of cells and accumulation of electron opaque deposits at the plasma membrane. The crater fills with stigmatic fluid and the diameter of the stylar canal increases. Pollen germinates in the secretion-filled crater, and pollen tubes grow down the style between the cells of the transmitting tissue but do not enter the canal. They emerge at the entrance to the ovary cavity and grow over one or two narrow strips of ovarian transmitting tissue cells which are present throughout the length of the ovary close to the ovules. This ensures that tubes grow in close proximity to the micropyles.     

Genes outside the S supergene suppress S functions in buckwheat (Fagopyrum esculentum)

BACKGROUND AND AIMS: Common buckwheat (Fagopyrum esculentum) is a dimorphic self-incompatible plant with either pin or thrum flowers. The S supergene is thought to govern self-incompatibility, flower morphology and pollen size in buckwheat. Two major types of self-fertile lines have been reported. One is a type with long-homostyle flowers, Kyukei SC2 (KSC2), and the other is a type with short-homostyle flowers, Pennline 10. To clarify whether the locus controlling flower morphology and self-fertility of Pennline 10 is the same as that of KSC2, pollen tube tests and genetic analysis have been performed. METHODS: Pollen tube growth was assessed in the styles and flower morphology of KSC2, Pennline 10, F1 and F2 plants that were produced by the crosses between plants with pin or thrum and Pennline 10. KEY RESULTS: Pollen tubes of Pennline 10 reached ovules of all flower types. The flower morphology of F1 plants produced by the cross between thrum and Pennline 10 were thrum or pin, and when pin plants were used as maternal plants, all the F1 plants were pin. Both plants with pin or short-pin flowers, whose ratio of style length to anther height was smaller than that of pin, appeared in F2 populations of thrum x Pennline 10 as well as in those of pin x Pennline 10. CONCLUSION: The results suggest that Pennline 10 possesses the s allele as pin does, not an allele produced by the recombination in the S supergene, and that the short style length of Pennline 10 is controlled by multiple genes outside the S supergene.     

The Role of Chemical Cues in Host and Mate Location in the Pear Psylla Cacopsylla bidens (Homoptera: Psyllidae)

Chemical communication was shown to play a role in the pear psylla, Cacopsylla bidens. Electrophysiological (EAG) and behavioral responses were investigated in males and females pear psylla . Males were found to be attracted to females, and especially to those on host plants, but not to males, uninfested host plants, or plants infested with conspecific larvae. On the other hand, females were not attracted to males or females but displayed some attraction to host plants. Furthermore, females showed a preference for uninfested pear versus plants infested with conspecific larvae. The antennae of males gave highest electroantenographic response to volatiles from pears infested with females but not males, while females, responded also toward the volatiles of pear alone. These results indicate that females of C. bidens emit sex pheromones that are attractive to the males and suggest that, host volatiles may play a role in host selection by pear psylla females.     

水稻msp1-4突变体的鉴定及其UDT1和GAMYB基因的表达分析

通过对粳稻‘9522’辐射诱变,得到一隐性雄性不育突变体msp1-4（MULTIPLE SPOROCYTE）,用遗传定位方法将该基因座位定位在分子标记WY-4和WY-8之间,相距0．8cM,物理距离247kb。测序分析证明这247kb区间中的MSP1基因的编码区在第758bp到767bp之间发生了10个碱基的缺失。形态学观察结果表明该突变体和已经报告过的msp1突变体的表型基本一致。为分析水稻其它与花药发育相关的基因在msp1-4中的表达变化,用半定量RT-PCR技术检测到影响绒毡层和花粉发育的重要基因UDT1和GAMYB的表达在突变体中比在野生型水稻中低,说明这2个基因可能位于MSP1基因的下游。     

The Role of the Cytoskeleton and Dictyosome Activity in the Pulsatory Growth of Nicotiana tabacum and Petunia hybrida Pollen Tubes

Pollen tubes of Nicotiana tabacum and Petunia hybrida show pulsatory growth. Phases of slow growth lasting minutes are interrupted by pulse-like elongations lasting 10–20 seconds involving an increase of growth rate by up to 24-fold. Inhibition of dictyosome activity with brefeldin A or monensin did not result in an inhibition of pulsatory growth but eventually stopped pollen tube elongation. In contrast to this the inhibition of the cytoskeletal elements with cytochalasin D and colchicine caused the pollen tubes to abandon the pulse-like elongations. It was concluded that the activity of the dictyosomes does not have a controlling function in the mechanism of pulsatory growth, even though it is necessary for pollen tube elongation, since cell wall material is provided by secretory vesicles deriving from the Golgi apparatus. In contrast the cytoskeletal elements, actin and microtubules, seem to play an important regulatory role in the pulse-like elongations. In addition, it was observed that during the experiments several pollen tubes burst upon the completion of a pulse-like expansion, indicating on the one hand that the internal turgor is the driving force of the pulse-like expansions. On the other hand, the bursting shows that the pollen tube cell wall is rather weak at the end of a pulse, indicating that at this point of time it is either thinner or less stable than during the slow growth phase or at the beginning of a pulse.