Alterations of Panicle Antioxidant Metabolism and Carbohydrate Content and Pistil Water Potential Involved in Spikelet Sterility in Rice under Water-Deficit Stress

Two rice genotypes with different drought tolerance, namely Jin 23B （drought tolerant） and Zhenshan 97B （drought sensitive）, were used to study the antioxidant enzyme activities, soluble sugar and starch contents in spikelets, pistil water potential and pollen number on a stigma under water-deficit stress at the flowering stage, which were involved in the spikelet sterility. Compared with respective controls, drought stress induced more serious decreases of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） activities and more significant increase of malonaldehyde （MDA） content in spikekets of Zhenshan 97B than in Jin 23B on 9 and 12 days after water stress （DAWS）. The soluble sugar and starch contents increased significantly in spikelets of Jin 23B, but decreased significantly in spikelets of Zhenshan 97B during 9-12 DAWS. The pistil maintained higher water potential in Jin 23B than in Zhenshan 97B during 3-6 DAWS and 9-12 DAWS. In addition, water stress induced more significant decrease in the pollen number on a stigma as well as the percentage of unfilled grains in Zhenshan 97B than in Jin 23B. Thus, it is suggested that water stress induced spikelet sterility by damaging antioxidant enzyme activities, reducing carbohydrate content in spikelets and decreasing pistil water potential at the flowering stage in rice.

Brassinosteroids mediate the effect of high temperature during anthesis on the pistil activity of photo-thermosensitive genetic male-sterile rice lines

Brassinosteroids(BRs)play critical roles in a wide range of plant developmental processes.However,it is unknown whether and how BRs mediate the effect of high temperature(HT)stress during anthesis on the pistil activity of photo-thermosensitive genetic male-sterile(PTSGMS)rice(Oryza sativa L.)lines.This study investigated the question.Three pot-grown PTSGMS rice lines were subjected to HT stress during anthesis.The contents of 24-epibrassinolide(24-EBL)and 28-homobrassinolide(28-HBL),the major forms of BR in rice plants,and levels of reactive oxygen species(ROS)or antioxidants(AOS),hydrogen peroxide(H2O2),1-aminocylopropane-1-carboxylic acid(ACC),ascorbic acid(AsA),and catalase activity in pistils,were determined.HT stress significantly reduced the contents of both 24-EBL and 28-EBL relative to those under normal temperatures,but the reduction varied by PTSGMS line.A line with higher BR contents under HT stress showed lower contents of ACC and H2O2,higher catalase activity and AsA content in pistils,and higher fertilization rate,seed-setting rate,and seed yield when the line was crossed with a restorer line,indicating that higher levels of BRs increase HT stress resistance.Applying 24-EBL,28-HBL or an inhibitor of BR biosynthesis confirmed the roles of BRs in response to HT stress.The results suggest that BRs mediate the effect of HT stress on pistil activity during anthesis and alleviate the harm of HT stress by increasing AOS and suppressing ROS generation.

Identifi cation of a novel male sterile wheat mutant dms conferring dwarf status and multi-pistils

Plant height and fertility are two important traits of wheat (Triticum aestivum L.), whose mutants are ideal materials for studies on molecular mechanisms of stem and lforal organ development. In this study, we identiifed a dwarf, multi-pistil and male sterile (dms hereafter) wheat mutant from Zhoumai 18. Simple sequence repeat (SSR) marker assay with 181 primer pairs showed that only one locus of GWM148-2B was divergent between Zhoumai 18 and dms. There were three typical phenotypes in the progeny of dms, tal (T;ca. 0.8 m), semi-dwarf (M;ca. 0.6 m) and dwarf (D;under 0.3 m) plants. Morphological investigation indicated that the internode length of M was shortened by about 20–50 mm each;the internode number of D was 2 less than that of T and Zhoumai 18, and its internode length was shorter also. The pol en vigor and hybridization test demonstrated that dms mutant was male sterility. Segregated phenotypes in progeny of M suggested that the multi-pistils and sterility were control ed by one recessive gene locus which was designated as dms temporarily, and the plant height was control ed by a semi-dominant gene locus Dms. Therefore, progeny individuals of the dms had three genotypes, DmsDms for tal plants, Dmsdms for semi-dwarf plants and dmsdms for dwarf plants. The mutant progenies were individual y selected and propagated for more than 6 generations, thus a set of near isogenic lines of T, M and D for dms were developed. This study provides a set germplasms for studies on molecular mechanisms of wheat stem and spike development.

Genetic mapping and expressivity of a wheat multi-pistil gene in mutant 12TP

We identified a wheat(Triticum aestivum L.) multi-pistil mutant from an F_2 breeding population in 2012, named 12 TP(three pistils in one floret). Genetic analysis showed that one dominant gene locus controlled the multi-pistil trait. Using homozygous normal and multi-pistil lines(near-isogenic lines; NILs) derived from the original mutant 12 TP, a simple sequence repeat(SSR) marker assay located the 12 TP locus on chromosome arm 2 DL. Four SSR markers were linked to 12 TP and their order was Xcfd233→Xcfd62-12 TP→Xwmc41→Xcfd168 at 15.85, 10.47, 2.89, and 10.37 cM, respectively. The average genetic expressivity of the trait ‘three pistils in one floret' was more than 98% in seven homozygous 12 TP lines; however, the average genetic expressivity in heterozygous F_1 plants was about 49%. Thus, the 12 TP is a semi-dominant gene locus, which differ from all previously reported multi-pistil mutants. Mutant 12 TP is a new useful germplasm for study of wheat floral development and for breeding of high yield wheat.

Separation and Identification of Stage-specific Proteins in Pistillate Flowers of Mulberry

In order to excavate the function genes of stage-specific proteins in the development process of mulberry pistillate flowers, using fruit mulberry cuhivar ＇ Da 10＇ as experiment material, two-dimensional electrophoresis and mass-spectrometric technology were used to investigate specifically expressed proteins of mul- berry pistillate flowers in different flowering periods. The results showed that 471 ± 4,450 ± 15 and 446 ± 14 protein spots were determined in mulberry pistil- late flowers at full-bloom stage, initial flowering stage and terminal flowering stage respectively, including nine protein spots with characteristics of stage-specific ex- pression and clear electrophoretic bands.. By mass spectrometry analysis, database retrieval and bioinformatics analysis, five components were successfully identi- fied as lactoylglutathione lyase-like protein, perchloric acid soluble translation inhibitor protein, ubiquitin-conjugating enzyme 1 like protein, putative ethylene re- sponse protein and 3-hydroxyisobutyrate dehychngenase, which were involved in stress resistance reaction, protein catabolism, signal transduction, glycometabolism and other biological processes in plants, which indicated that these proteins might play an important biological function in the normal development and pollination fertilization of mulberry pistillate flowers.

Flower morphology of Allium(Amaryllidaceae)and its systematic significance

Allium is a complicated genus that includes approximately 1000 species.Although its morphology is well studied,the taxonomic importance of many morphological traits,including floral traits,are poorly understood.Here,we examined and measured the floral characteristics of 87 accessions of 74 Allium taxa(belonging to 30 sections and nine subgenera)from Central to Eastern Asian countries.We then examined the taxonomic relationships between select flower characteristics and a phylogenetic tree based on ITS sequences.Our results confirm that floral morphology provides key taxonomic information to assess species delimitation in Allium.We found that perianth color is an important characteristic within the subg.Melanocrommyum,Polyprason,and Reticulatobulbosa.In subg.Allium,Cepa,and Rhizirideum,significant characteristics include ovary shape,perianth shape,and inner tepal apex.For species in subg.Angunium,the key taxonomic character is ovule number(only one ovule in per locule).In the subg.Allium,Cepa,Polyprason,and Reticulatobulbosa,which belong to the third evolutionary line of Allium,hood-like appendages occur in the ovary,although these do not occur in subg.Rhizirideum.Our results also indicated that the flower morphology of several species in some sections are not clearly distinguished,e.g.,sect.Sacculiferum(subg.Cepa)and sect.Tenuissima(subg.Rhizirideum).This study provides detailed photographs and descriptions of floral characteristics and information on general distributions,habitats,and phenology of the studied taxa.

青皮竹花形态结构与雌、雄配子的发育研究

[目的]揭示青皮竹自然条件下不同发育阶段花器官的形态及其雌、雄配子体的解剖结构特征。[方法]采用形态解剖及石蜡制片的方法对青皮竹花器官的各部分外观形态特征以及雌、雄配子体的发育过程进行观察与描述。[结果]青皮竹小穗为无限花序,下部的小花先发育,但因小穗基部具有潜伏芽,因此又具有有限花序的特征。每个小穗约有8~10朵小花,顶端小花不育,小穗基部含有2~3枚黄棕色苞片。每朵小花均有内、外稃各1枚,浆片3枚,雄蕊6枚,雌蕊1枚。雌雄异熟,异花授粉。子房呈花瓶状,下部光滑不具棱,上部有绒毛。子房1室,侧膜胎座,倒生胚珠,双珠被。短花柱长柱头,花柱具绒毛,三分枝羽状柱头。花药呈黄色,4药室。未成熟的花药的花药壁由外向内依次为表皮、药室内壁、中层和绒毡层。绒毡层为腺质型,花药成熟后绒毡层退化,仅剩表皮和纤维层。花粉成熟后2或3核花粉粒,花药壁纵裂散粉。[结论]青皮竹花器官形态与解剖结构发育正常,而雌、雄配子体发育过程中出现多种败育情况,可能是青皮竹结实率低的重要原因。

新疆南疆5个杏品种开花的生物学特性

以新疆南疆库买提等5个杏品种为试材,对其花期、花粉生活力、雌蕊败育率、柱头可授性及坐果率进行了调查,为该地区杏栽培授粉品种配置及高产稳产提供参考。结果表明:5个品种中,大白油杏花芽萌动期最早,吾候其和大白油杏始花期均最早,吾候其盛花期最早;同时品种间花芽萌动期变异系数最大,为51.35%,末花期变异系数最小,为5.66%。库买提花粉萌发率最高,与晚熟佳娜丽存在显著差异。雌蕊败育率在不同品种间差异显著,雌蕊败育率最高的是大白油杏,最低的是库买提。柱头最佳授粉时期具有差异,其中,库买提、晚熟佳娜丽、吾候其分别在花后第2 d和第3 d柱头达极强可授性。坐果率与雌蕊败育率呈极显著负相关关系,与花粉生活力呈正相关关系。5个杏品种花期持续6~9 d,吾候其、库买提的花粉生活力、坐果率均较强;大白油杏、晚熟佳娜丽雌蕊败育率均较高;库买提、晚熟佳娜丽、吾候其的柱头在最佳授粉时期均表现出极强的可授性。

Morphogenesis of Pistillate Flowers of Cercidiphyllum japonicum(Cercidiphyllaceae)

Floral morphogenesis and the development of Cercidiphyllumjaponicum Sieb. et Zucc. were observed by scanning electron microscopy （SEM）. The results showed that the pistillate inflorescences were congested spikes with the flowers arranged opposite. Great differences between the so-called ＂bract＂ and the vegetative leaf were observed both in morphogenesis and morphology. In morphogenesis, the ＂bract＂ primordium is crescent-shaped, truncated at the apex and not conduplicate, has no stipule primordium at the base but does have some inconspicuous teeth in the margin that are not glandular. The leaf primordium is triangular, cycloidal at the apex, conduplicate, has two stipule primordia at the base, has one gland-tooth at the apex occurring at first and some gland-teeth in the margin that occur later. In morphology, the ＂bract＂ is also different to the vegetative leaf in some characteristics that were also illustrated in the present paper. Based on the hypothesis that the bract is more similar to the vegetative leaf than the tepal, we considered that the so-called ＂bract＂ of C.japonicum might be the tepal of the pistillate flower in morphological nature. Therefore, each pistillate flower contains a tepal and a carpel. We did not find any trace of other floral organs in the morphogenesis of the pistillate flower. Therefore we considered that the unicarpellate status of extant Cercidiphyllum might be to highly reduce and advance characteristics that make the extant Cercidiphyllum isolated from both fossil Cercidiphyllum-like plants and its extant affinities.

Anatomical studies of ovule development in the post-bloom pistils of the 'Zuili' plum (Prunus salicina Lindl.)

In order to investigate the cause of poor fruit set in 'Zuili' plums,anatomical examinations of post-bloom pistils were conducted and the dates of young fruit drop were recorded during the growing seasons of 2008 and 2009.Pistils of cv.'Black Amber' were also examined as an abundant setting control.Two major dropping periods were detected in 'Zuili':one during the first 5 d after full bloom (DAF) and another between 10 and 17 DAF.Anatomical analyses of the pistils at the full bloom stage revealed that half of the ovules had not developed embryos,which may have caused their early drop.In most dropped pistils collected at 17 DAF,the micropyle had not been penetrated by a pollen tube,indicating that they were not fertilized.'Zuili' ovules initiated embryo division at 10-12 DAF,although thereafter embryo development was retarded when compared to the rates observed in 'Black Amber'.Ovule fertilization failure and inactive embryo development after ovule fertilization may be the major causes of the later fruit drop observed in 'Zuili' plum trees.

毛蕊异黄酮对氧化损伤的星形胶质细胞增殖与凋亡的影响

目的 探讨毛蕊异黄酮对氧化损伤的星形胶质细胞(astrocyte, AS)的增殖、凋亡的影响。方法 原代分离大鼠脊髓星形胶质细胞,并利用免疫荧光检测胶质纤维酸性蛋白(glial fibrillary acidic protein, GFAP)进行鉴定。分别加入5、10、20μmol·L^(-1)毛蕊异黄酮预处理脊髓星形胶质细胞12 h,然后加入过氧化氢(H_(2)O_(2))处理24 h,造成氧化损伤模型,CCK8检测各组细胞增殖情况,选择合适的毛蕊异黄酮处理浓度。实验分组包括空白对照组、模型组、模型+毛蕊异黄酮预处理组。CCK8检测各组细胞增殖情况,流式检测各组细胞凋亡和周期情况,免疫荧光检测各组细胞样本中BrdU水平,蛋白免疫印迹法(Westernblot)检测各组细胞中蛋白酪氨酸激酶2(januskinase2,JAK2)、信号转导和转录激活因子3 (signal transducers and activator of transcription3,STAT3)、糖蛋白130(recombinant glycoprotein130,GP130)、白细胞介素-6 (interleukin-6,IL-6)的蛋白表达水平。结果 H_(2)O_(2)处理能够抑制脊髓星形胶质细胞的增殖并诱导其凋亡(P<0.05),氧化损伤模型细胞组中p-JAK2、p-STAT3、GP130、IL-6的蛋白表达水平显著增加(P<0.05),而毛蕊异黄酮预处理后能够减轻H_(2)O_(2)造成的氧化损伤,促进增殖和抑制凋亡(P<0.05),并显著抑制了p-JAK2、p-STAT3、GP130、IL-6的蛋白表达水平(P<0.05)。结论 毛蕊异黄酮能够促进氧化损伤的星形胶质细胞增殖并抑制其凋亡,可能通过抑制JAK2/STAT3通路磷酸化起作用。

小麦 Tappc3A 基因克隆及功能预测

PEPC可催化磷酸烯醇式丙酮酸(PEP)生成草酰乙酸(OAA)进入三羧酸循环,对植物的生长发育和逆境适应发挥重要作用。但目前尚无关于PEPC参与植物器官发育的报道。发掘并研究小麦Tappc3A在花发育中的生物学功能,为探究小麦雄蕊同源转化为雌蕊性状的分子机制提供新的线索。通过PCR技术从CM28TP和HTS-1中克隆Tappc3A基因,使用生物信息学工具分析基因序列及系统进化关系,利用qRT-PCR技术分析Tappc3A在小麦幼穗不同发育阶段和不同生殖器官中的表达水平,通过原核表达分析Tappc3A基因编码的蛋白功能是否正常,利用小麦RNA-Seq数据库分析Tappc3A与其他调控花器官发育基因之间的共表达情况。Tappc3A基因的ORF长2901 bp,编码966个氨基酸残基,具有典型的磷酸烯醇式丙酮酸羧化酶(PEPase)保守结构域,N端具有保守的丝氨酸(Ser,S)可逆磷酸化位点(SIDAQLR),C端具有植物型PEPC蛋白特征序列(QNTG),第774位氨基酸为C3植物PEPC典型的丙氨酸。聚类分析也表明,Tappc3A属于C3型PEPC家族。qRT-PCR分析表明,在小麦幼穗发育的3个阶段,二棱期至小花分化期和药隔时期,HTS-1中的Tappc3A基因的表达量高于CM28TP,且Tappc3A在雌蕊(P)和雌蕊化雄蕊(PS)中的表达量显著高于雄蕊(S)。原核表达结果显示,Tappc3A基因编码的蛋白能催化PEP生成OAA,并且在IPTG诱导后活性明显增强。基因共表达分析显示,Tappc3A可能参与了小麦花器官的形态发生。小麦Tappc3A可能参与小麦雌蕊发育,其在雄蕊中的过量表达可能与雄蕊同源转化为雌蕊性状形成有一定的关联。

蔷薇科果树自交不亲和性分子机制研究进展

植物自交不亲和性是植物花粉—雌蕊相互识别,防止其近亲繁殖的重要机制,是植物发育生物学的研究热点之一。蔷薇科果树如梨、苹果、李子等表现出自交不亲和性,该反应由S位点(S-locus)的一对S等位基因,即雌蕊和花粉的S基因控制,分别为S-RNase和S-locus F-box/S-haplotype-specific F-box基因。本文综述了蔷薇科果树雌蕊和花粉S基因的鉴定及其结构和进化的特性、自交亲和性突变机制及自交不亲和性反应发生过程中花粉生理生化变化及其信号转导机制等,以期为深入系统研究蔷薇科果树自交不亲和及亲和性机制提供参考。

山楂受精能力与其花粉和雌蕊生理生化特性的关系

用受精能力强的野生山楂的花粉给受精能力差的 3个栽培品种‘面楂’、‘敞口’、‘大金星’授粉 ,并对野生山楂和栽培山楂花粉与雌蕊的部分生理生化指标进行了比较。结果表明 ,野生山楂的花粉能显著提高栽培山楂种子含仁率。栽培山楂与野生山楂花粉生活力无显著差异 ,但栽培山楂花粉萌发率较低 ,花粉管生长速度较慢 ,其中‘大金星’花粉在 2 5℃培养 2 4h不能萌发。栽培山楂雌蕊提取液对栽培山楂和野生山楂花粉萌发都有抑制作用。与野生山楂相比 ,栽培山楂花粉中类胡萝卜素、游离脯氨酸和可溶性蛋白质含量较低 ,酚类化合物含量和POD活性较高 ,其中‘大金星’花粉中类胡萝卜素和可溶性蛋白质含量最低 ,酚类化合物含量和POD活性最高。雌蕊中IAA氧化酶活性明显高于野生山楂 ,而可溶性糖含量低于野生山楂。‘敞口’、‘大金星’和‘面楂’雌蕊中POD同工酶分别比野生山楂多 2、3、4条酶带 。

油菜诸葛菜属植物杂交亲和性研究

以雄不育系甘蓝型油菜Ad2为母本,诸葛菜、湖北诸葛菜和铺散诸葛菜为父本,进行属间杂交结果表明,不同生态型诸葛菜与母本的亲和性基本一致。湖北诸葛菜与甘蓝型油菜杂交可能存在受精前障碍,铺散诸葛菜与甘蓝型油菜有较弱的亲和性,杂交种与其亲本与甘蓝型油菜的亲和性略有差别。父本的基因型对远缘杂交花粉萌发和花粉管的生长有一定影响。远缘杂交中可能存在受精延迟现象。蕾期授粉是克服属间杂交不亲和性的有效方法。

磷对板栗结实性能及产量的影响

试验结果表明,磷对板栗(Castanea mollissima Blume)雌花的形成数量有重要影响,结果母枝含磷量与母枝抽生结果枝数量和着生雌花数量呈显著正相关。板栗结果母枝含磷量比雄花母枝和营养枝分别高5.19％和5.27％。树体磷素含量水平与板栗雌、雄花枝比例和结果枝结栗苞数量也存在密切的相关性。在不同施磷水平下,结果枝粗度与果枝结栗苞数均具有显著的回归关系,但b值差异大。本研究结果在鄂东大别山区进行了大面积施磷肥示范,生产实践证明,施磷肥对板栗具有一致的增产效益。

核桃优良品种雌雄花授粉活力的研究

在核桃花期,柱头的可授性和花粉活力直接决定着座果率和当年产量。本文采用具有代表性的核桃优良品种‘温185’、‘强特勒’和‘清香’,在记录柱头授粉受精形态变化的同时,用联苯胺--过氧化氢法确定了柱头的可授时期;用MTT染色法确定了花粉活力期限和花粉活力最高的条件和时期。结果表明:柱头可授时期在柱头微张至出现棕色条纹之间,最佳时期在柱头开张后3～5d;自然状态下花粉可保存96h,但4h后生活力即降至33%,雄花刚开放时花粉生活力最高,达95%。花粉在4℃条件下可延长生活力,120h平均生活力为63.3%。

薄壳山核桃无性系开花物候特性观测

通过对6个薄壳山核桃无性系开花物候、花期长短、雌花开花数量以及雄花序数量等进行观测。结果表明,不同薄壳山核桃无性系雌雄花开花物候差异明显,6个无性系间雌花差异最长为10 d,差异最短为2 d;6个无性系间雄花差异最长为9 d,差异最短为1 d。6个薄壳山核桃无性系雌花、雄花序数量差异极显著(P<0.01),无性系21号、28号和104号雌花开放数量大,可以将其定为高产、丰产的主栽品种;无性系5号、27号、35号雄花序数量大,可以将其定为授粉品种,为其它花期相遇的无性系授粉用。根据试验的研究结果,无性系5号、27号、35号可以作为无性系21号、28号和104号的授粉品种。