云南紫稻细胞质雄性不育系花药发育过程中Ca2+的分布特点

运用焦锑酸钾沉淀法研究了云南紫稻细胞质雄性不育系和保持系花药在发育过程中Ca^2 的分布特点。结果表明,保持系的花粉母细胞和小孢子的胞质内部基本无Ca^2 的沉淀,后期花粉外壁出现Ca^2 的沉淀;保持系早期的绒毡层细胞形态正常,胞内有少量Ca^2 沉淀,后期绒毡层细胞开始凋亡,胞质凝集,胞内出现大量Ca^2 的颗粒。不育系花粉母细胞在减数分裂时期败育,胞质液泡化,内部出现大量Ca^2 的沉淀;不育系绒毡层细胞形态正常,胞内无Ca^2 的沉淀。绒毡层与花粉母细胞、小孢子之间出现大量Ca^2 颗粒。探讨了不育系花药花粉母细胞中以及与绒毡层细胞之间Ca^2 的异常积累与雄性不育的关系。     

水稻马协不育与可育花药ATPase定位（简报）

Pb3 (po4)2-precipitation was used to study the ATPase activities both in fertile and sterile anthers of rice (Oryza sativa L. cv. Marxie). At big-vacuole pollen stage, tapetum of the fertile anthers showed high ATPase activity in their nuclei. In fertile pollen, ATPase was localized on the outside surface of the exine and in the nucleus both at big-vacuole and at bi-nucleate pollen stage. At late bi-nucleate pollen stage, a large amount of Pb3 (PO4)2 precipitated in endintine of the fertile pollen. In sterile anthers, tapetum was fully degenerated at big-vacuole pollen stage. In sterile pollen, ATPase was localized both on the plasmamembrane and in intine. These phenomena lasted to the bi-nucleate pollen stage. In addition, most of the sterile pollen did not show well-developed endintine. Based on the above results, we suggested that abortive tapetum could not provide enough nutrition for pollen development, and the high ATPase activity both on plasma membrane and in intine would likely result in ATP shortage in sterile anthers.     

水稻马协不育与可育花药ATPase定位(简报)

马协不育系系朱英国等用农家品种“马尾粘”的不育株与“协青早选”测交和回交选育成功的。超微结构研究表明马协不育花药单核边位期绒毡层提前解体,液泡膜破裂;不育花粉外壁基粒棒少,且分布不均匀;线粒体有大的电子透明区,二核期不育花粉中央大液泡崩溃。不育花药绒毡层提前解体可能影响花粉外壁合成及花粉营养供应,大量研究表明绒毡层发育异常与花粉败育密切相关,而液泡膜的破坏会导致水解酶类的泄     

Calcium distribution in fertile and sterile anthers of a photoperiod-sensitive genic male-sterile rice

Potassium antimonate was used to locate Ca²⁺ in fertile and sterile anthers of a photoperiod-sensitive genic male-sterile rice (Oryza sativa L. japonica). During the development of fertile anthers, abundant calcium precipitates accumulated in the anther walls and on the surface of pollen grains and Ubish bodies at the late developmental stage of the microspore, but not in the cytoplasm of pollen grains. Following the accumulation of starch grains in pollen, calcium precipitates on pollen walls diminished and increased in parenchymatous cells of the connective tissue. In sterile anthers, calcium precipitates were abundant in the middle layer and endothecium, but not in the tapetum, as was found in fertile anthers. A special cell wall was observed between the tapetum and middle layer of sterile anthers that appeared to relate to distinctive calcium accumulation patterns and poor pollen wall formation in the loculi. The formation of different patterns of antimonate-induced calcium precipitates in the anthers of photoperiod-sensitive genic male-sterile rice indicates that anomalies in the distribution of calcium accumulation correlate with the failure of pollen development and pollen abortion. Received: 30 May 1997 / Accepted: 5 July 1997     

New acritarch species from Holocene sediments in central West Greenland

Anther development, microsporogenesis, and microgametogenesis were studied using both light and TEM microscopy in the six accessible subdioecious/cryptically dioecious species of Consolea (Cactaceae). Anther wall development, microsporogenesis, and microgametogenesis are uniform in staminate flowers of all six species, and are typical for Cactaceae. Breakdown of microsporogenesis in male‐sterile anthers occurs early, at the onset of meiosis, and results in anthers bearing no pollen grains. The abortive process follows a common pattern in all investigated species. The tapetum is the first layer to deviate from normal male‐fertile anther development. Tapetal cells in male‐sterile anthers elongate at an early stage and have abundant rER with atypical configurations. Ultimately, the tapetum becomes hypertrophied and non‐functional. Male‐sterility in pistillate flowers appears to be directly related to these anomalies. In addition, other anther layers and tissues are affected, and normal patterns of programmed cell death (PCD) are disrupted. The relationship between these patterns and the pattern of PCD in normal male‐fertile anthers is discussed. We hypothesize a single origin for the cryptically dioecious/subdioecious breeding system of Consolea based on the uniformity of the anther's abortive processes in pistillate flowers.     

Male sterility and restored fertility in annual mercuries, relations with sex differentiation

The paper summarizes the researches conducted on male sterility in Mercurialis annua. Totally sterile individuals are very scarce in the dioecious species showing as the other Mercuries, unisexual flowers devoid of rudiments of the opposite sex. From one sterile male mutant, a ‘sterile series’ was conducted and genetics was studied. Sterile, semisterile, restored fertile male lines were constructed as well as female lines containing the inducer gene of male sterility, both fertility restorers and the sensitive cytoplasm. Morphology and ontogeny of these isogenic lines were presented. Male sterile anthers (empty) present a splitted tapetum and an abnormal meiotic end. Restored fertile male lines were normal. The relative abundance of auxin and cytokinins was studied. A specific cytokinin pathway measured as a background in fertile lines, the cis-oxidized pathway characterised the ‘sterile series’. Restoration of normal meiosis and tapetum appeared for the highest quantities of cis-zeatin (669 ng instead of 192 ng/100 g fresh weight in totally sterile). Auxin quantities were abundant compared with the normal males. Gene expression in the ‘sterile series’ was also compared with the fertile lines. t-RNAs specific for normal females were expressed in the male ‘sterile series’. Hybridization kinetics and in vitro translations pf poly(A)⁺RNAs demonstrate specific sequences for each line. Comparisons between identical organs (normal fertile male/restored fertile male or normal female/female of the ‘sterile series’) exhibited nearly 10% differences. The results suggest that for stamen development, a cascade of regulators probably exists: sex genes acting on the induction of stamen or pistil, then genes for sterility/restoration of fertility acting in anthers. Fertility-sterility regulators control the synthesis of a specific cytokinin pathway. The new hormonal signals are linked to several specific genes expressed in the floral morphology characterizing each line of the ‘sterile series’.     

水稻非花粉型细胞质雄性不育系及其保持系花药发育过程中Ca2+的分布变化

钙在高等植物中被称为第二信使,与植物的有性生殖有关。为了研究水稻（Oryza sativa L.）花药中钙的定位与花粉败育的关系,利用焦锑酸钾沉淀法研究了非花粉型细胞质雄性不育系G37A及其保持系G37B花药的发育过程及其细胞中Ca^2＋ 的分布变化。研究发现,在2个材料间花药中钙的分布存在大量差异。G37B的可育花药在花粉母细胞时期及二分体时期,很少看到有Ca^2＋的沉积;而在单核花粉时期,Ca^2＋沉积急速地增加,主要定位在绒毡层细胞、花粉外壁外层及乌氏体的表面;随后花药壁上沉积的Ca^2＋减少而花粉的外壁外层仍然有很多Ca^2＋沉积物。相反,G37A的不育花药在花粉母细胞时期和二分体时期有大量的Ca^2＋沉积在小孢子母细胞和花药壁,中间层和绒毡层特别多。在二分体时期之后,不育花药的Ca^2＋沉积减少,特别是绒毡层内切向质膜附近的Ca^2＋几乎消失。但是同时期的可育花药中,有大量的Ca^2＋沉积在绒毡层。不育花药的Ca^2＋沉积在开花几天后消失。根据研究结果推测在不育花药发育早期中更多的钙离子与花粉败育有一定的关系。     

Mechanism of male sterility in Petunia

Summary The free amino acid contents in the anthers of male fertile, cytoplasmic male sterile (cms) and genic male sterile (gms) petunia lines were compared at different developmental stages of the male gametophyte. Quantitative differences in the amounts of free amino acids were found between the fertile and male sterile lines and between the cms and gms lines. The differences between the sterile lines were correlated with the different developmental stages at which the breakdown in microsporogenesis occurred. In the Rosy Morn (RM) cms line, where breakdown of microsporogenesis occurred at the end of prophase 1, there was an associated increase in asparagine and decrease in the other amino acids. In the RM gms line, in which breakdown occurred at the tetrad stage, an accumulation of asparagine in the anthers corresponded with an accumulation of glutamine beginning at prophase 1. Compared with fertile anthers, the sterile anthers accumulated much proline at the early meiotic stages, but no -aminobutyric acid. Comparison of the free amino acids of the fertile and the male sterile lines indicates that certain biochemical events leading to breakdown of microsporogenesis precede the observed cytological breakdown. The results from adding asparagine and glutamine to extracts of anthers at different developmental stages suggest that the amino acid balance may contribute to the changes in pH in the fertile and male sterile anthers which we observed previously.Contribution from the Volcani Center, Agricultural Research Organization Bet Dagan, Israel. 1972 Series, No. 2083 E.     

The persistence and lignin-like appearance of the primary cell wall of microsporocytes in male-sterile (CMS) sweet pepper,Capsicum annuum L

Using differential staining of cell walls the anatomy of microsporogenesis was investigated on cross-sections of anthers of fertile plants of the sweet pepperCapsicum annuum L. cv. Severka, as well as of its sterile analogues. The lignin-like staining as observed in the microsporocyte primary walls of fertile plants disappears with their getting independent in the course of meiosis. On the contrary, in sterile plants the stain increases in intensity, the thick-walled microsporocytes usually form a continuous block up to the period of tetradogenesis, and so far as microspores originate, they are not dissociated outwards. Moreover, in sterile anthers the external tapetum is usually not differentiated.     

ORGANELLE SIZE AND NUMBER IN FERTILE AND T-CYTOPLASMIC MALE-STERILE CORN

Anthers of inbred F₄₄ fertile (N) and cytoplasmic male-sterile (T) corn plants (Zea mays L.) were compared cytologically. No differences between fertile and sterile anthers were observed in size and number of mitochondria or plastids until after the start of anther degeneration. A rapid division of mitochondria was observed, however, in the tapetum and sporogenous cells of both fertile and sterile anthers during early growth stages. This rapid increase in mitochondrial numbers per cell (some 20-to 40-fold) preceded tapetal breakdown in sterile anthers and did not occur in other anther cells or in plastids. Limited observations on the megagametophyte and nucellus revealed that mitochondria in ovules remain relatively constant in size and number during gametogenesis and do not undergo degeneration.     

Microsporogenesis in male sterile Rosmarinus officinalis L. (Lamiaceae), an ultrastructural study

Within an extensive reproductive biology program on Rosmarinus officinalis a study of microsporogenesis in male sterile plants has been carried out. Two events, related to the two types of male sterile flowers found in this species (MS; Male sterile and INT; Intermediate male sterile flowers), are described. The first event is characterized by the early appearance of necrotic areas in the anther tissues during the final differentiation phases of the MS flowers, before meiosis takes place. Initially, these necrotic areas are small, later on they enlarge affecting the sporogenous tissue and tapetum. All the anthers in which necrosis has begun finally become aborted and lack pollen grains. The second event is manifested in the anthers of the INT flowers. Previous to the release of the microspores from the callosic envelope, vacuolisation of the tapetal cells takes place. The tapetum does not properly carry out its secretory function. It accumulates some substances in vacuoles and starch granules in plastids. The microspores degenerate in the vacuolate stage. In the epidermal and endothecial cells modifications are observed which may be related to the carbohydrate metabolism. Indehiscent, whitish anthers containing inviable microspores result. We have not found significant differences between the mitochondria in the anthers of the fertile flowers and MS or INT flowers. But we suggest, for both events, a metabolic failure, possibly controlled by cytoplasmic genes as the origin of male sterility. Paracrystalline material has been detected in microspore nuclei of developing INT anthers, though it does not seem to be related to the expression of male sterility.     

Histological aspects of microsporogenesis in fertile,cytoplasmic male sterile and restored fertilePetunia hybrida

Summary A comparative histological study is made of microsporogenesis in fertile, cytoplasmic male sterile and restored fertilePetunia. Microsporogenesis in sterile anthers proceeds normally until leptotene. The development of the restored fertile type at 25°C is normal until the tetrad stage. In both types sporogenesis arrests and the meiocytes, c.q. microspores ultimately degenerate. The first phenomena of deviation are found in the tapetum. The effects of degeneration on cellular structure, vacuolation and cytoplasmic organization of the tapetal and sporogenous cells are variable. The deposition of callose around the meiocytes appears independent of the process of degeneration. The absence of an increase in callase activity possibly explains the remnants of callose found at late stages of development. The failure of callose wall dissolution appears to be the result of metabolic abnormalities in the tapetum and is regarded as an indirect effect of sterility.     

Effects of Petunia cytoplasmic male sterile (CMS) cytoplasm on the development of sterile and fertility-restored P. parodii anthers

The developmental defects causing cytoplasmic male sterility in Petunia parodii are described in isonuclear fertile, sterile, and fertility-restored plants using both light- and scanning electron microscopy. The aberrant development of the sporogenous tissue and tapetal layer caused by the cytoplasmic male sterile cytoplasm in both Petunia hybrida and P. parodii nuclear backgrounds is similar in onset and progression. The degeneration of the sporogenous tissue and tapetal layer of sterile anthers is first apparent late in meiosis and results in highly abnormal sterile sporogenous tissue by tetrad stage of fertile anthers. The stomium and endothecium do not show major developmental differences between fertile and sterile anthers, but the inner connective tissue of sterile anthers contained calcium crystals not found at high abundance in fertile anthers. Ovoid bodies containing magnesium and phosphorus were seen only in the vascular bundles of fertile anthers. Material prepared for the scanning electron microscope by freeze drying showed better retention of fragile morphological features, while critical-point drying permitted examination of nonvolatile structures, such as cell walls.     

ABA and IAA control microsporogenesis in <Emphasis Type="Italic">Petunia hybrida</Emphasis> L.

The formation of fertile male gametophyte is known to require timely degeneration of polyfunctional tapetum tissue. The last process caused by the programmed cell death (PCD) is a part of the anther program maturation which leads to sequential anther tissue destruction coordinated with pollen differentiation. In the present work, distribution of abscisic acid (ABA) and indole-3-acetic acid (IAA) in developing anthers of male-fertile and male-sterile lines of petunia (Petunia hybrida L.) was analyzed by using the immunohistochemical method. It was established that the development of fertile male gametophyte was accompanied by monotonous elevation of ABA and IAA levels in reproductive cells and, in contrast, their monotonous lowering in tapetum cells and the middle layers. Abortion of microsporocytes in the meiosis prophase in the sterile line caused by premature tapetum degeneration along with complete maintenance of the middle layers was accompanied by dramatic, twofold elevation in the levels of both the phytohormones in reproductive cells. The data obtained allowed us to conclude that at the meiosis stage ABA and IAA are involved in the PCD of microsporocytes.     

Cytochemical investigation of genic male-sterility in Chinese cabbage

A genic male sterile Chinese cabbage, Brassica campestris L. ssp. chinensis Makino, was examined using cytological and cytochemical methods to characterize the process of pollen abortion in this plant. Thick sections of both fertile and sterile anthers at different developmental stages were stained using Toluidine Blue O, Periodic Acid-Schiff’s (PAS) reaction and Sudan Black B to detect cytochemical changes that may occur in the distribution of insoluble polysaccharide and lipid storage bodies. Pollen abortion in sterile anthers occurs at an early stage of microspore development. During early microspore development, reductions in the number of starch grains in the connective tissue of fertile anthers coincide with the accumulation of starch grains in cells of the anther wall. In the late microspore stage, a large vacuole forms in the microspore, and tapetal cells synthesize and accumulate lipid droplets. The cellular organization of tapetal cells in sterile anthers appears similar to that in fertile anthers, except for the absence of lipid droplets in cells of sterile anthers and diffusely labeled tapetal polysaccharides, suggesting defects in nutrient storage. Supported by National Natural Science Foundation of CHINA (30170060)     

Proteolytic activity in anther extracts of fertile and cytoplasmic male sterile petunia

Proteolytic activity is compared in anther extracts from Petunia parodii fertile and cytoplasmic male sterile lines. It is characterized relative to developmental stage of the anthers, effect of variable incubation times, pH of isolation buffers, and degradation of marker proteins. In fertile anthers, proteolytic activity increases at the end of microsporogenesis and peaks early in microgametogenesis. Degradation is most severe in extracts of fertile anthers and in high molecular weight proteins and reaches its maximum within 20 minutes. Degradation of marker proteins is greatest at pH 5.6 to 8.0 in fertile anther extracts and is eliminated under strong acid conditions (pH 2.8 to 4.0) in both fertile and cytoplasmic male sterile anther extracts. Marker proteins degrade more severely in extracts of fertile anthers; however, the order of substrate sensitivity—myosin > phosphorylase b > bovine serum albumin and ovalbumin > β-galactosidase—is the same in extracts from fertile and cytoplasmic male sterile anthers.     

Differences on the microsporogenesis and tapetal development of male fertile and cytoplasmic male sterile pepper (Capsicum annuum L.)

To clarify the time and cause of pollen abortion, differences on the microsporogenesis and tapetum development in the anthers of male fertile maintainer line and cytoplasmic male sterile (CMS) line pepper were studied using transmission electron microscopy. The results showed that CMS line anthers appeared to have much greater variability in developmental pattern than male fertile maintainer line ones. The earliest deviation from normal anther development occurred in CMS line anthers at prophase I was cytomixis in some microspore mother cells (MMCs), and vacuolisation in tapetal cells. Then, MMCs in CMS line anthers developed asynchronously and a small part of ones at the different stage degenerated in advance appearing to have typical morphological features of programmed cell death (PCD). Most MMCs could complete the meiosis, but formed non-tetrahedral tetrad microspores with irregular shape and different size and uncertain number of nuclei, and some degenerated ahead of time as well. Tapetal cells in CMS line anther degenerated during meiosis, and were crushed at the tetrad stage, which paralleled the collapse of pollens. Pollen abortion in CMS line anthers happened by PCD themselves, and the premature PCD of tapetal cells were closely associated with male sterility.     

DNA synthesis and cytoplasmic differentiation in tapetal cells of normal and cytoplasmically male sterile lines of Petunia hybrida

Summary A new method is described by which tapetal cells may be isolated from anthers of cytoplasmic male sterile (CMS) and fertile lines of Petunia hybrida. Using a combination of stereometry and Feulgen densitometry it has been possible to chart DNA synthesis and nuclear division with great precision within these cells. Results are presented which show CMS lines both to synthesize far less DNA than the fertiles and also to undergo less cell division. These differences in DNA kinetics and cytokinesis are obvious long before any differences between sterile and fertile lines may be detected in the meiocyte mass. In addition to these difference in nuclear behaviour, the tapetal cells of CMS lines also synthesize far lower levels of rough endoplasmic reticulum than do their fertile counterparts. Again, this difference is evident at a very early stage of anther development when all other cell components, including mitochondria and plastids, appear normal. These data are discussed in terms of the very special differentiation undergone by tapetal cells in angiosperms, and the conclusions drawn are considered in the perspective of current hypotheses proposed to explain the operation of CMS.     

雄性不育与可育楸树花发育的细胞学比较研究

楸树（Catalpa bungei C.A.Meyer.）属紫葳科(Bignoniaceae)梓树属(Catalpa),落叶乔木,是我国特有的珍贵优质用材树种。本文用石蜡切片法对可育株和雄性不育株楸树的大、小孢子发生及雌、雄配子体发育过程进行了详细地比较观察。结果表明：可育株和不育株楸树雌蕊的发育基本相同,胚珠倒生,薄珠心,单珠被,胚囊发育为蓼型。可育株雄蕊花药四室,药隔薄壁组织发达;异型绒粘层,由药壁绒粘层和药隔绒粘层组成;花药壁表皮细胞在小孢子母细胞减数分裂前后开始径向伸长加厚,直到花药开裂并不降解,这可能与花药开裂有关;成熟花粉为四合花粉。雄性不育株花药的早期发育到次生造胞细胞时期与可育雄蕊的相同,小孢子母细胞减数分裂前绒毡层发育不充分;四分体时期,绒毡层细胞高度液泡化,细胞质稀薄,已提前降解,小孢子四分体因绒毡层结构和功能异常而不能正常发育,因此楸树雄性不育为结构型雄性不育。